Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Mongrel714 on May 28, 2026, 04:57:38 am
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Hello all,
Try this again, I am building my first amp, I'm using the chassis from a Hammond organ, An AO-37, not a prime amp to convert, but I have cut down the chassis, and re arranged the components, I'm ordering some parts and getting ready to solder, I look forward to learning this craft, please take a look and see if I'm going in the right direction as far as wiring and parts, Ill have al new components except for the transformers, any parts that are on there now are place holders! Thanks in advance!
(https://i.postimg.cc/J0GTgB0S/IMG-20260526-063112844-HDR.jpg)
(https://i.postimg.cc/cCnJJr2D/IMG-20260527-062710366-HDR.jpg)
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Ok cool, I have seen the "Go her first" page so I will be looking through that as I go along, Thanks again!
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Hey guys, I do have a question here, The way the Heater twisted pairs are running, and the Blue and red from the Output tranny, with that as it is will the wires to the speaker jacks be ok were they are? in general will all the wiring be ok how it is run?? Thank you!!
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Your heater wires are nicely twisted. The priority is to keep your signal wires away from your AC (heater and mains) wires -- that's where you will have real problems.
Avoid running your output wiring in parallel with AC. If you need to run output wires across heaters, which most designs will do, cross at or near 90 degrees and separate in the Z dimension, just like Leo did back in the day.
Don't get stuck on the wiring at this stage. Do understand that this is a learning process, and have fun with it.
You should have a plan drawn out. Much easier to erase pencil lines than desolder wires and re-drill holes!
For a first amp, I always favor Doug Hoffman's plans -- go to https://hoffmanamps.com/MyStore/perlshop.cgi?ACTION=enter&thispage=PartsListIndex.htm&ORDER_ID=!ORDERID!#google_vignette (https://hoffmanamps.com/MyStore/perlshop.cgi?ACTION=enter&thispage=PartsListIndex.htm&ORDER_ID=!ORDERID!#google_vignette) to find an amp similar to your design, and then check out the project links on the right, which will give you some ideas.
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If this was my project, I'd relocate the output transformer closer to the middle of the chassis, so that the wires could be run in more of a straight line to the power tubes and output jacks. That hole you have near V2 and V3 would be where I'd put it.
By the way, what amp model are you aiming to build? Looks like a push-pull of some sort. Knowing that would help people give you advice.
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I believe your OT is wired wrong. That OT has three primary wires. Blue and Brown should go to the output tube plates and red (center tap) should go to B+.
I agree with dogburn. That OT is located in a bad place. I suggest putting it between the rectifier socket and the output sockets. That will simplify those long wiring runs and the problems they may cause.
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acheld and Dogburn, and sluckey, Thank you for the reply's!
What I was hoping to build is a JCM 800 type 50w circuit, I don't know yet if the transformer is the proper voltage, The circuit I'm looking at is posted below,
I have been debating on moving the output transformer, so now Ill do that, and the signal wire advice will be taken acheld!
and sluckey, thank you for noticing that, I will correct that, mentioning the rectifier socket, using the diagram below, should I use the tube rectifier, or go with a Solid state rectifier here? I have already ordered a components kit with all the smaller resisters and caps, diodes, so whichever I should use would be fine with me!
The turret board I'm using is 10" long so its a little cramped but should work, will there be a problem running anything under it given enough clearance?
I installed the proper fuse holder next to the power inlet, I have another on the way for the H.T. Thanks again guys!
Pics!
(https://i.postimg.cc/L8VxPLsP/JCM8002-diagram.png)
(https://i.postimg.cc/RZPc9RFR/IMG-20260529-124950096-HDR.jpg)
(https://i.postimg.cc/mZqWnfRX/IMG-20260529-003651750-HDR.jpg)
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From the output Tranny green and yellow wires to the speaker jacks, will the center tap (Black wire) go to ground?
THX!
Phones dead, Ill post the pic tomorrow!
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Are you planning on a set of EL34's in there?
I think those Hammond AO 20936-5 output transformers are for a pair of 6V6, not sure if one of the green and yellow wires may be for a specific feedback loop for that type of organ it came from [see this post on Hammond S6 from this forum]
https://el34world.com/Forum/index.php?topic=28335.0 (https://el34world.com/Forum/index.php?topic=28335.0)
The output transformers secondary wiring should be black to ground and green to hot on the output jack socket for 8 ohms, then the yellow is for a loop
I would recommend doing a JCM800 with 6V6 pair, 15w is plenty for home playing, I'm rocking a 2w JCM micro at the moment and its awesome!
Have a good read through these pages:-
https://www.sluckeyamps.com/6v6plexi/6v6plexi.htm (https://www.sluckeyamps.com/6v6plexi/6v6plexi.htm)
https://mhuss.com/Plexi6V6/ (https://mhuss.com/Plexi6V6/)
It would be worth researching the transformers first, testing the mains transformer to get the power specs [which should be good for 2x 6V6 and a few preamp tubes]
Good to check the measurements from the output transformer, DC resistance measurements on the black green and yellow wires can help identify which order they go in, but a test with a small amount of AC into the transformer will help even more to get an accurate measurement of the ratios
Don't get stuck on the wiring at this stage. Do understand that this is a learning process, and have fun with it.
Take your time with the base layer of the amp, sometimes it feels like the most boring bit, just drilling holes and endless filing but it is the foundation it all sits on....
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For your question on rectification, I would stick with solid state, since that was part of the Marshall design. If you switch to a tube rectifier, you would have to re-think the filter/reservoir caps to make sure they are appropriate for the rectifier and you'd have to make sure the power transformer can provide enough current for the 5V heaters of the rectifier.
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Hey guys, Thank you, this is the information Im needing, I am a noob at this so any info you guys can give me is greatly appreciated! Rontone, There is a lot of great info in these posts, I've read and will re read it several times.
The amp originally was running 6BQ5 tubes, (EL84's?) and the amp did work, you could hit the power button and jam out on some organ music! But I'm a guitar player soooo..The amp will spend the rest of its life amplifying guitars!
I've been watching Kley de Jongs videos to kind of get my footing here on where the hookups should be made, mainly this one:
it show a lot of the hookups he has made, but I will be concentrating on the pages you've sent me now to figure this out, the DC resistance on the OT is as follows:
Primary
Brown-Red:.102K
Blue-Red: .1127K
Brown-Blue- .219K
Secondary
Yellow-Black:0.2 ohms
Black-Green: 0.2 ohms
Yellow-Green: 0.4ohms
I have to de solder the leads on the PT to get the Resistance on it,
and I will be working on the VAC testing this evening to see what its putting out.
Thank you dogburn, I will be removing the Rectifier tube socket as my parts will be arriving on Mon. by the way the rec tube was a 5U4GC if that info is needed.
And gentleman, I am having a blast doing this, I have wanted to build a guitar amp for a very long time now, since I was on the road in the 80's Hair Metal craze!
Back then I ran through a JCM 800 100 watt, Traded that for a 100W early 60's Plexi, and the last road band I was in I ran two early 60's 50W Marshall heads with a double stack, nothing like standing in front of 16-12" speakers and feeling the air move! But I digress,
Thanks again guys, you dont know how much I appreciste the help!
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And by the way, I did move the OT guys,
(https://i.postimg.cc/RNWFmj68/IMG-20260529-140248665-HDR.jpg)
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...the DC resistance on the OT is as follows:
Primary
Brown-Red:.102K
Blue-Red: .1127K
Brown-Blue- .219K
This confirms my earlier comment that the OT was wired wrong. Do not connect the red wire to a output tube socket!
I believe your OT is wired wrong. That OT has three primary wires. Blue and Brown should go to the output tube plates and red (center tap) should go to B+.
Another thing... Those transformers are designed for 6BQ5s or 6V6s. They will not be happy trying to work with EL34s!
And one more thing... The JCM800 2204 is a high gain amp. It will be very picky about layout. Your layout is far from optimized for a 2204.
BTW, the new location for the OT is much better.
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Thanks sluckey, I always aim a little to high, So Ill get measurements from the PT and well go from there.
I can live with a lower wattage, I'm not playing out now anyway, I just want to make something that sounds good and learn along the way!
and yes, the old setup used 6BQ5 tubes, (Those are equivalent to EL84's?) but since I have the Octal sockets installed I would rather go for the 6V6!
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Hey guys, I have all the leads from the PT un hooked, Can I Check each set of leads by hooking up the multi meter and pluging the cord in? Forgive me if this is a dumb question as I have not done this, but I will search now and see what comes up!
Well everything I've read says not to do this, so I'll wait and see what you guys say!
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OK as far as PT resistance we have:
Red to red HV: 92.7ohms
Red to Red/yellow CT: 47.6 ohms
red to red/yellow CT: 45.1 ohms
Yellow to yellow: 0.2 ohms
Large brown vinyl
to Large brown Vinyl: 0.2ohms
LBV to Grey CT:0.2 ohms
LBV to Grey CT: 0.2 ohms
Braided orange to
braided orange: 19.4 ohms
Black to black: 1.9 ohms
No continuity to any other lead, no continuity to ground.
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I did a search to check the AO-37's original setup, saw your reply on 18watt forum, so was this amp from a F100 Extravoice Organ?
With this schematic? [page 24 for Power Supply and Power Amp] - https://archive.org/details/HammondOrganF-100ExtravoiceServiceManual/page/n24/mode/1up (https://archive.org/details/HammondOrganF-100ExtravoiceServiceManual/page/n24/mode/1up)
I was just wondering what those other taps on the power transformer were for
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Yes that's the one, It had a bank of 10-12AU7s with small transformers I assume for the "Extravoice" ? Maybe that was the 25V tap, (the two braided orange wires), the 5V to the rectifier socket (yellow), two large brown pvc are 6.3V, two red are B+ to rectifier socket, red and yellow CT ran to B- terminal, (Will that run to the center tap B+ on the PT?) Two black to power switch/fuse, Here's some pics that may or may not help!
(https://i.postimg.cc/KzfKR2f2/IMG-20260513-001327713-HDR.jpg) The PT was in a separate small enclosure on the bottom with a terminal strip on the outside.
(https://i.postimg.cc/rsvqpnv9/IMG-20260512-215741610-HDR.jpg) This is that strip, on the prior pic it runs top to bottom, switch end at top. It also had a separate socket maybe a test plug socket?
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That's got to be a pretty massive PT, and it will certainly have the current to run all the tubes you have planned. Since it used a 5U4, the 5V tap should be rated for at least 3A.
Looking back at your photos, it looks like the amp model is AO-27, not 37.
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It would be worth researching the transformers first, testing the mains transformer to get the power specs [which should be good for 2x 6V6 and a few preamp tubes]
Good to check the measurements from the output transformer, DC resistance measurements on the black green and yellow wires can help identify which order they go in, but a test with a small amount of AC into the transformer will help even more to get an accurate measurement of the ratios
Ok, Im going with the 6V6 version, On the OT, do I need a variac, or is there another way to apply power to these, all the plug in power supplies I have including a 12V laptop power supply switch the power to DC. Ill research this see if I can find out what to use.
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I think I have the same PT. There was like 20 preamp tubes in the schematic I have, and 2 6V6 so you'll likely have quite high plate voltage. Probably somewhere between 400-450V. Mine reads 474 unloaded.
You will have to knock down the heater voltage with some series resistors, the heater winding is built for a lot of current to bring the voltage down to 6.3V.
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I think I have the same PT. There was like 20 preamp tubes in the schematic I have, and 2 6V6 so you'll likely have quite high plate voltage. Probably somewhere between 400-450V. Mine reads 474 unloaded.
You will have to knock down the heater voltage with some series resistors, the heater winding is built for a lot of current to bring the voltage down to 6.3V.
Ah thank you Al, I was kinda wondering about that being so many 12AU7s!! Ive got enough sockets to last awhile!
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Yeah, you're smart to change to 6v6 over el84's. The PT could handle el34's or 6l6's easily, but the OT kind of confines you to the smaller wattage model. That being said, you'll have to also adjust your signal voltage to work with the smaller output tubes compared to the 2204 schematic.
Personally I'm holding on to that transformer for some sort of stereo audio amp, but it comes in handy now for testing other circuits.
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Yeah, you're smart to change to 6v6 over el84's. The PT could handle el34's or 6l6's easily, but the OT kind of confines you to the smaller wattage model. That being said, you'll have to also adjust your signal voltage to work with the smaller output tubes compared to the 2204 schematic.
Personally I'm holding on to that transformer for some sort of stereo audio amp, but it comes in handy now for testing other circuits.
Thanks again Al, At the moment Im trying to figure out how to check the output on the Power Transformer, was watching one guy use a lightbulb current limiter to test the individual taps, I know the big brown tap is 6.3V, The yellow should be 5V, the orange colored is 25V, The B+ circuit is kind of what Im trying to find out, not very comfortable with this procedure though, just dont want to blow up my transformer!
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Ok, Finally got the guts up to test voltage, On the OT I have
120VAC in on primary blue and brown wires= secondary Green and black wire=1.3 V
"" "" "" "" "" """ """ """ "" "" "" "" = Secondary Yellow and black wires=1.3V
On the PT we have:
120 VAC in on black wires= 2 orange wires=28.8V output
2 yellow wires= 5.3V output
2 B Brown wires=7.3V output (You were right Al)
2 Red HV to Red/yellow CT=336V output
So to figure ratios, Divide input by output, but on the OT Gr Bl,,Yel/bl do you use 1.3 V or add the two together and use 2.6V?
Thanks for the help all!!
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Yes, a light bulb limiter is a good idea. Plugging into a GFI is also a good idea.
On mine, there's the 2 big brown wires, that are the heater supply. There's also a smaller green wire which is the heater center tap. The black wires are the primaries.
There's 5 red/orange wires. The smaller 2 are the bias supply, the larger 3 are the high voltage.
You can measure resistance across the 3 HV wires and find which one is the center tap. Mine is 80R across both, and 40R/side.
You can test all of this with the amp unplugged. Don't test voltages unless you're sure of what you're doing.
Then you can plug in and measure voltage from each HV winding to the HV center tap. Should be around 330V AC.
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secondary Green and black wire=1.3 V
"" "" "" "" "" """ """ """ "" "" "" "" = Secondary Yellow and black wires=1.3V
Not sure I understand this, your PT must be different than mine.
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secondary Green and black wire=1.3 V
"" "" "" "" "" """ """ """ "" "" "" "" = Secondary Yellow and black wires=1.3V
Not sure I understand this, your PT must be different than mine.
On the Output transformer, I input 120VAC into the primary Blue and brown wires, I measured 1.3V output from the secondary yellow/Black wires, and the green/black wires for 2.6V.
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I thought you were talking power transformer. No idea of your OT.
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Uncle Doug has a good video on finding the ratio and impedance of the OT.
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Uncle Doug has a good video on finding the ratio and impedance of the OT.
Was just watching that one, lots of info!
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That's got to be a pretty massive PT, and it will certainly have the current to run all the tubes you have planned. Since it used a 5U4, the 5V tap should be rated for at least 3A.
Looking back at your photos, it looks like the amp model is AO-27, not 37.
Naw, its AO-37, The chassis was so long I cut it in half! I got some goodys in, this was for JCM 800 build, but Im sure we can use some for the 6V6!
(https://i.postimg.cc/sDqgq62k/IMG-20260602-191249003.jpg)
(https://i.postimg.cc/cL3LSRgn/IMG-20260602-181542893-HDR.jpg)
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Hey Guys, I have been thinking about it and I really want to build the 50watt JCM, I'm getting a new 50 watt OT for my Birthday later this month, I'm building a Marshall correct chassis, (we have a metal break and whole metal shop, wood shop, graphics shop, were I work! I already have the amp head cabinet 70% finished, the electronics package is for the JCM 800, so here we go!!
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I'm not crazy about the bias power supply switching off with the Standby switch. Should be powered in Standby like the heaters. There are better layouts out there as was mentioned. I attached the last 50 watt I assembled. Bias power is not switched off in Standby.
acheld and Dogburn, and sluckey, Thank you for the reply's!
What I was hoping to build is a JCM 800 type 50w circuit, I don't know yet if the transformer is the proper voltage, The circuit I'm looking at is posted below,
I have been debating on moving the output transformer, so now Ill do that, and the signal wire advice will be taken acheld!
and sluckey, thank you for noticing that, I will correct that, mentioning the rectifier socket, using the diagram below, should I use the tube rectifier, or go with a Solid state rectifier here? I have already ordered a components kit with all the smaller resisters and caps, diodes, so whichever I should use would be fine with me!
The turret board I'm using is 10" long so its a little cramped but should work, will there be a problem running anything under it given enough clearance?
I installed the proper fuse holder next to the power inlet, I have another on the way for the H.T. Thanks again guys!
Pics!
(https://i.postimg.cc/L8VxPLsP/JCM8002-diagram.png)
(https://i.postimg.cc/RZPc9RFR/IMG-20260529-124950096-HDR.jpg)
(https://i.postimg.cc/mZqWnfRX/IMG-20260529-003651750-HDR.jpg)
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Thanks for the input JPK, I have totally shelved that mess, I have a new chassis built and starting to assemble, Taking my time with it, Wanting this to be closer to JCM 800 2204 style, please keep the comments and help coming, I need it!
(https://i.postimg.cc/QdGVG2yD/IMG-20260607-004356774.jpg)
(https://i.postimg.cc/Yjc27F8M/IMG-20260607-004338149.jpg)
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I'm not crazy about the bias power supply switching off with the Standby switch.
Yeah, and the fusing on the Secondary HT can be better, have a look at some standby and fusing ideas here:-
https://www.valvewizard.co.uk/standby.html (https://www.valvewizard.co.uk/standby.html)
https://www.valvewizard.co.uk/fuses.html (https://www.valvewizard.co.uk/fuses.html)
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Bias switching off with standby, does that mean the tubes are un biased when the standby is on? What effect does this have?
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Bias switching off with standby, does that mean the tubes are un biased when the standby is on? What effect does this have?
See post #13.
https://el34world.com/Forum/index.php?topic=23011.0
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I'm not crazy about the bias power supply switching off with the Standby switch.
Yeah, and the fusing on the Secondary HT can be better, have a look at some standby and fusing ideas here:-
https://www.valvewizard.co.uk/standby.html (https://www.valvewizard.co.uk/standby.html)
https://www.valvewizard.co.uk/fuses.html (https://www.valvewizard.co.uk/fuses.html)
That makes sense, I wondered why my current amp had a couple fuses inside, now I know, still a little confused as to the location of the fuse to protect the PT, I'll re read that a few times till it sinks in my thick skull, I remember nights on the road and blowing a fuse in my Plexi, "give me some aluminum foil!!" Sometimes it would get me through the night, other times It didn't!! Anyways, thanks guys! Keep the knowledge coming!
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Neither layout in this thread gets the standby switch correct to the schematic they're noted to be based on.
Both disable the bias supply whilst in standby mode, thereby causing an enormous cathode current surge when standby is flipped.
Because the bias supply takes much longer to charge up than the anode and screen grid HT supply nodes.
Ok, got it!
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I'm not crazy about the bias power supply switching off with the Standby switch.
Yeah, and the fusing on the Secondary HT can be better, have a look at some standby and fusing ideas here:-
https://www.valvewizard.co.uk/standby.html (https://www.valvewizard.co.uk/standby.html)
https://www.valvewizard.co.uk/fuses.html (https://www.valvewizard.co.uk/fuses.html)
(http://I made some changes to the diagram for safety reasons....
Moved put the power switch before the fuse and made sure the "hot" side for both fuse holders was on the tip and not the ring.
I had it the way I did in the diagram for convenience then realized as I was mounting the switches in the chassis that if I followed my diagram the mains fuse holder would always be hot even when the switch was off, that's the opposite of good. If someone were to replace the fuse while holding a guitar they could get a potentially lethal dose of voltage through the chest.
I also added 47k 2w resistors parallel to the standby switch for a "soft power-up".
I have joined the "standby switches aren't necessary" camp, yet want to include one to satisfy my nostalgia.)
Will this work? if not which way should I go??
(https://i.postimg.cc/KzPrRNbt/JCM8002204WHTFusing.jpg)
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'"Im not crazy about the bias power supply switching off with the Standby switch. Should be powered in Standby like the heaters. There are better layouts out there as was mentioned. I attached the last 50 watt I assembled. Bias power is not switched off in Standby."
Ok I have studied these all day and I do see what you mean, In the fuse page I was sent too it said better to fuse on the AC side than the DC side, After diodes is DC?? is that correct? and it talks about fusing both leads, I have not seen one schematic with that fusing, I see the positive about it, but is it really a must or is it ok to just use the HT fuse already on the amp? the way you and others have it wired up? Thanks guys!
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You keep quoting my posts about the standby switch wiring asking about fusing, but it was Rontone that made the fuse comment. I'll defer to him to answer the fusing questions.
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You keep quoting my posts about the standby switch wiring asking about fusing, but it was Rontone that made the fuse comment. I'll defer to him to answer the fusing questions.
Sorry bout that, having some long days at work.
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Ok I have studied these all day and I do see what you mean, In the fuse page I was sent too it said better to fuse on the AC side than the DC side, After diodes is DC?? is that correct? and it talks about fusing both leads, I have not seen one schematic with that fusing, I see the positive about it, but is it really a must or is it ok to just use the HT fuse already on the amp? the way you and others have it wired up? Thanks guys!
I was away for a few days then,
Yes, good to fuse the HT on the AC side, the diodes are the point where the AC is rectified to DC, in the case of the two layouts from further up the page, the rectifier is a two phase type,
Some manufacturers put the HT fuse in the centre tap of the HT winding, I have a few old amps with that fusing and never had a problem, and some Marshalls do it after the rectifier, so you will see two fuse holders on the rear, one for Primary and one for Secondary, but as mentioned on Merlin's Valvewizard site there are some faults which can still leave current flowing even if that centre tap fuse blows, so ideally on a "two phase" rectifier two fuses, one for each leg of the HT, just help protect the transformer a bit more...
Has the "Triode Electronics" layout above been edited, it looks like the two HT fuses have been added, along with another after the rectifier, so there is 4 altogether, also I cannot see the component legs on the board, feels like I'm going colour blind, are the component legs just a slightly darker shade of red :w2:
If the amp is well built, setup and running well you would be fine with the "old" style or the two fuse way, as long as you don't put bacofoil in those fuse holders ever again :icon_biggrin:
[I bought an old Sound City once, poor thing used to run so hot, 6x EL34's in there so I just assumed it was that at first, but then I found a Kitkat wrapper in the fuse holder, there was so much jammed in there I bet it would have done more than 10 amps through it before it burned out, it was like solid metal in the holder...]
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Ok I have studied these all day and I do see what you mean, In the fuse page I was sent too it said better to fuse on the AC side than the DC side, After diodes is DC?? is that correct? and it talks about fusing both leads, I have not seen one schematic with that fusing, I see the positive about it, but is it really a must or is it ok to just use the HT fuse already on the amp? the way you and others have it wired up? Thanks guys!
I was away for a few days then,
Yes, good to fuse the HT on the AC side, the diodes are the point where the AC is rectified to DC, in the case of the two layouts from further up the page, the rectifier is a two phase type,
Some manufacturers put the HT fuse in the centre tap of the HT winding, I have a few old amps with that fusing and never had a problem, and some Marshalls do it after the rectifier, so you will see two fuse holders on the rear, one for Primary and one for Secondary, but as mentioned on Merlin's Valvewizard site there are some faults which can still leave current flowing even if that centre tap fuse blows, so ideally on a "two phase" rectifier two fuses, one for each leg of the HT, just help protect the transformer a bit more...
Has the "Triode Electronics" layout above been edited, it looks like the two HT fuses have been added, along with another after the rectifier, so there is 4 altogether, also I cannot see the component legs on the board, feels like I'm going colour blind, are the component legs just a slightly darker shade of red :w2:
If the amp is well built, setup and running well you would be fine with the "old" style or the two fuse way, as long as you don't put bacofoil in those fuse holders ever again :icon_biggrin:
[I bought an old Sound City once, poor thing used to run so hot, 6x EL34's in there so I just assumed it was that at first, but then I found a Kitkat wrapper in the fuse holder, there was so much jammed in there I bet it would have done more than 10 amps through it before it burned out, it was like solid metal in the holder...]
Hey rontone, Thanks for the answer, I feel a little less in the dark now!! Yes, I put the two fuses before the rectifier just to see if that was the wat to go, and ya, the lines on the circuit board are darker red, didnt notice that, I will fix that and re post the original, and no worries, no more foil! that was my younger and dumber days!! Thanks so much :worthy1:
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Here we go!(https://i.postimg.cc/kXzV7gMP/JCM8002204WHTFusing.jpghttps://i.postimg.cc/kXzV7gMP/JCM8002204WHTFusing.jpg)
Just dis regard the fuses till we figure out which way to go!
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Hello al, I have always been leery of Aliexpress, I went ahead and ordered some resistors as they were so cheap really just to see if they would come and be the right thing, Now I've seen a 50watt Output transformer on there for around $60-70, has anyone tried these?? and if so, what WAS THE VERDICT?? Thanks guys!
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Hello all, Sorry I know I've jumped around from design to design, But I have settled on the Tube town JC 18 type build, I have nearly completed the build, going over voltages and startup procedures, I am using a current limiter, but getting no light in the bulb, the bulb is good, the amp comes on I can get some voltages which I will post below with pics, I get a light "pop" from the speaker now and then when removing a meter lead, any how the voltages I have are,
B+ These measurements are off the can caps,
1-405VDC
2-369VDC
3-335VDC
4-331VDC
EL84, off the pins,
Plate-403VDC
Grid-41VDC
Screen-369VDC
(https://i.postimg.cc/j5RYXLDH/tt-jc18-schem.png)
(https://i.postimg.cc/Gh9m5v0S/tt-jc18-layout.png)
(https://i.postimg.cc/cJhhCpDL/IMG-20260802-173435095.jpg)
(https://i.postimg.cc/gJ0DZg5V/IMG-20260802-173327571.jpg)
I have yet to get voltage readings from some pins due to being afraid the voltage is to high and I dont want to damage the tubes, saying that, I installed the EL84s and turned them on long enough to warm up and they looked a little to bright, so I quickly turned it off and removed them, I just need to know what to do next, any info or pics you need please let me know, will be glad to do what it takes to get this running!
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(https://i.postimg.cc/MWQZzBxF/tt-jc18-schem.png)
Noticed the Schematics would not zoom.
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Grid-41VDC
That's way too much bias voltage. Should be about -15v for EL84s.
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Grid-41VDC
That's way too much bias voltage. Should be about -15v for EL84s.
How do I go about fixing that?, Ive noticed Ive left off some ground wires, Im fixing that, then I will re check.
Thanks for the comment !!
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Is that +41 or -41V? Looks like your bias diode is backwards. Fix that and double check before you put the tubes in again! The bias voltage should be negative relative to ground.
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Is that +41 or -41V? Looks like your bias diode is backwards. Fix that and double check before you put the tubes in again! The bias voltage should be negative relative to ground.
Ah ok, thank you, will do!
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The bias resistors are backwards!
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Well didnt help much, heres what were running now,
B+ These measurements are off the can caps,
1-405VDC-405
2-369VDC-369
3-335VDC-335
4-331VDC-328
EL84, off the pins,
Plate-403VDC-405
Grid-41VDC-25
Screen-369VDC-370
I'm running 100k resistors on pin 2 The grid, what really bothers me is there is 404VDC going to the Stand by switch, rated for 250VAC, I'm kinda baffled here, do I add some more dropping resistors? Thanks for any help!
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Looks like your bias diode is backwards.
Let me repeat, this time a little louder... YOUR BIAS DIODE IS BACKWARDS!!!!!
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Looks like your bias diode is backwards.
Let me repeat, this time a little louder... YOUR BIAS DIODE IS BACKWARDS!!!!!
Sorry, I'm usually not this air headed, I did turn around the two resistors instead of the Diode, I mis read.
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Ok, now on pin 2 the volts go up to around 7 then back to zero and stay there, Ive got the meter set on 20vdc.
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Ok, now on pin 2 the volts go up to around 7 then back to zero and stay there, Ive got the meter set on 20vdc.
That's still not good. I suspect you may have damaged the two 10µF bias caps when the diode was backwards. Replace them.
Take both EL84s out of the amp and don't put them back in until you can measure approx -15V (that's negative 15 volts) on pin 2 of both EL84 sockets.
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Ok, did some research while I was at work today, I had the Bias voltage coming from the tube rectifier, which is wrong, un hooked that, soldered it to the HT lead out of the power transformer and boom, uh no, not boom, it worked, I have -41 volts! Turning the Bias pot went up to -61volts, Is that high? It was supposed to have a 50k trim pot on the board, I have a 25k Trim pot, so I wired up a 50 k pot instead, have to find out if that is wired correctly or not, You can see it in the pics, the wiper and right term wired together then to the 68k resistor, the right terminal to the 10uf cap and ground, let me know what you think ! Thanks a ton everyone!
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I've told you twice how much voltage you should have.
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I've told you twice how much voltage you should have.
Very sorry I asked again.
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No need to apologize. I'm not trying to discourage you. I know you are learning and I'm trying to help. Just wish you would listen a little more closely.
You're well on your way to having the bias voltage fixed. You just need to lower the bias voltage to work with EL84s. You can do this by increasing the size of R105. I suggest start with 220K and go up/down in size until you have about -15V on pin 2 of the EL84 sockets.
As mentioned earlier, I highly recommend replacing those two 10µF bias caps because they have been severely stressed when you had that positive voltage on them. There's a good chance that the EL84s are damaged as well.
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Thank you Sluckey, I do appreciate that, with my Job which is 10 hr days and a lot to do and take care of in my home plus car trouble and health stress I am a little frazzeled right now, I would not have started this project if I wasn't positive I could complete it, but I have stretched my self a little thin at the moment, But no worries, nothing a good nights sleep and a couple weeks vacation wouldn't cure!
But really thank you, I give you the respect for your years of knowledge and thank you for passing it along!
I will be ordering some new caps and now tubes, and changing that resistor to find the correct value (when the new caps arrive!)
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Hey guys, Another question, I have a new choke, Hammond 194G, 3H @250mA, 79.92 Ohms resistance, At the moment this amp project has a 1,5K 5Watt resistor along with a couple more 10k 3 watt resistors and a 220k 3 watt resistor, in this resistor network, can I remove the 5w resistor and replace it with the choke, and would that help the power supply, or is this a try it and see type problem? I planned to use this choke on this project anyway, so what is your opinion?
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Don't do it! That 3H/250mA choke needs to have nearly 250mA current flowing through it to be effective. There is only about 15mA flowing through that 1K/5W resistor. The resistor will be way more effective than that big ole choke.
Read this google search (https://www.google.com/search?q=will+a+choke+rated+for+3H+and+250mA+be+effective+in+a+powersupply+that+only+has+a+15mA+load%3F&oq=will+a+choke+rated+for+3H+and+250mA+be+effective+in+a+powersupply+that+only+has+a+15mA+load%3F&gs_lcrp=EgRlZGdlKgYIABBFGDkyBggAEEUYOTIHCAEQ6wcYQNIBCTkyNjA1ajBqNKgCALACAQ&sourceid=chrome&source=chrome.ob&ie=UTF-8) for more details.
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Don't do it! That 3H/250mA choke needs to have nearly 250mA current flowing through it to be effective. There is only about 15mA flowing through that 1K/5W resistor. The resistor will be way more effective than that big ole choke.
Read this google search (https://www.google.com/search?q=will+a+choke+rated+for+3H+and+250mA+be+effective+in+a+powersupply+that+only+has+a+15mA+load%3F&oq=will+a+choke+rated+for+3H+and+250mA+be+effective+in+a+powersupply+that+only+has+a+15mA+load%3F&gs_lcrp=EgRlZGdlKgYIABBFGDkyBggAEEUYOTIHCAEQ6wcYQNIBCTkyNjA1ajBqNKgCALACAQ&sourceid=chrome&source=chrome.ob&ie=UTF-8) for more details.
Ahh, thank you, Ill save it for a bigger amp build, I knew you would have the answer!
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Working on the amp and my rectifier tube got mangled. I thought I would try a SS rectifier but even with a power resistor and a couple 10k 3watt resistors voltages coming off the rectifier is 413VDC,
at the EL84 screen grid its is 379V still -15 at pin2, But I guess Im ordering a new rec tube to get the voltages back down to a manageable level, unless there is another fix out there?? let me know, and thank you!
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I have ran over and over the schematics for the amp I am trying to build, and I'm finally seeing how the schematics applies to the layout, and the more I check the work I've done on this thing, the more correct it seems, as far as how I have it all hooked up, If I can get the voltage right, barring any bad solder joints or failed parts, I believe when I load up the tubes I will have a positive out come, even with the voltage as it is, there are no parts burning or smoking when I'm testing, My current limiter bulb is not lit, I've just got to get my new Rectifier tube and my new caps in and hopefully we'll be making some noise with this thing!
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Nobody really knows what you've built at this point. Tubes won't burn, they'll just break down, and when they do, they could wipe out every other part in the circuit they're attached to. I suggest you copy the schematic you used, and use a program like paint to indicate any changes you made to the design, and then make a voltage chart at idle for every node on the power supply and pin on the tubes.
It seems to me you're running pretty high voltage for EL84's.
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Just going to chime in to say it sounds like your current limiter is likely mis-wired. Given the other issues you've had, I would think you would absolutely want that working, just in case.
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Nobody really knows what you've built at this point. Tubes won't burn, they'll just break down, and when they do, they could wipe out every other part in the circuit they're attached to. I suggest you copy the schematic you used, and use a program like paint to indicate any changes you made to the design, and then make a voltage chart at idle for every node on the power supply and pin on the tubes.
It seems to me you're running pretty high voltage for EL84's.
All right, thank you for the reply, I will do that, The circuit Im using is the "Tube Town" JC 18, I listed earlier, but yes Ive changed out some resistors so I will do the layout and voltage as asked, do I measure with tubes in or out? as it is right now, I have my B+1 and B+2 in the ballpark for voltage, my Neg bias is at -15VDC also, But I will sit down tonight or sometime tomorrow and layout all this and post it, thank you again!
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Just going to chime in to say it sounds like your current limiter is likely mis-wired. Given the other issues you've had, I would think you would absolutely want that working, just in case.
Yes I would say your right, I am working on that right now, hopefully will have that fixed soon.
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Although I think you may have skipped this step, normally it's a good idea to follow some sort of start up procedure. Here's a link to a good thread.
https://el34world.com/Forum/index.php?topic=2376.0
Once you've found out everything is running properly, then measure voltages with tubes in. Hopefully you haven't damaged your power tubes already when your bias voltage was missing.
You installed the 1R resistor at the cathode of the power tubes? That measurement is important. Otherwise, you'll have to measure resistance across the transformer to find current of the power tubes.
Don't forget to measure AC voltage at the heaters.
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Although I think you may have skipped this step, normally it's a good idea to follow some sort of start up procedure. Here's a link to a good thread.
https://el34world.com/Forum/index.php?topic=2376.0
Once you've found out everything is running properly, then measure voltages with tubes in. Hopefully you haven't damaged your power tubes already when your bias voltage was missing.
You installed the 1R resistor at the cathode of the power tubes? That measurement is important. Otherwise, you'll have to measure resistance across the transformer to find current of the power tubes.
Don't forget to measure AC voltage at the heaters.
Actually I have followed that, just have to go over it again, I have a tube tester and all the tubes are in the 90+ range, the tester was recently calibrated and resistors replaced, The 1R resistor is a bias test point on the schematics, In just about finished with the amended schematics and layout, will include the heater voltage on that
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Hey guys, here's where I'm at so far, still have not put tubes in to try, I wanted to see if the voltages were in the safe zone to try, (the "Uncle Doug" video I watched says they are in range, although the PI may be a bit low)
Rectifier-+352V
B+1-+270v
B+2-+261v
B+3-+120v
B+4-+121v
EL84
pin 7-+268V
pin 9-+257v
PI
pin 6-+122v
pin 1-+122v
Pre amp
pin 6-+122v
Filiments-3.6vac
Bias--15vdc
I have listed changes on the layout, still working on the schematic.
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No tubes?
Schematic needed.
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heres schematics, its 5:30 am, will do voltage when I'm awake this afternoon.
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Screen resistors are usually 100 to 470 ohms not 470K ohms. Typo? If you are using these values to reduce the B+ voltage they will overheat and burn. I suspect your donor power transformer makes too much voltage for your power tubes. However it might be suitable for 6V6GT???
Use separate 1 ohm resistors on each tube to measure tube bias. These numbers should be mv (millivolts).
Measure bias voltage where R21 and R22 connect to each other. This number should be volts
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In your effort to make the power supply voltages match the original schematic with no tubes installed you have really messed up the dropping resistors. I suggest putting the original resistor values back in and also removing that 20K that's between the diodes and the first filter cap. Then put the tubes in and connect the power cord directly to the wall. Your lightbulb is no longer needed. Now your power supply will have a proper load, and your voltage readings will be realistic.
All those voltage readings with the amp plugged into a lightbulb limiter and no tubes plugged in are really meaningless.
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Ok, will do that tonight, I was following a another build with the same kind of components (Hammond transformers) so that's the reason for the odd values, yes that was a typo, the amp had EL84s in it when I removed it from the organ, my lack of knowledge here has been a real handicap.
So thank you for the help guys.
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Screen resistors are usually 100 to 470 ohms not 470K ohms. Typo? If you are using these values to reduce the B+ voltage they will overheat and burn. I suspect your donor power transformer makes too much voltage for your power tubes. However it might be suitable for 6V6GT???
Use separate 1 ohm resistors on each tube to measure tube bias. These numbers should be mv (millivolts).
Measure bias voltage where R21 and R22 connect to each other. This number should be volts
AC, help me to get this through my thick skull, Do I connect the 1K resistor(s) to the points where r21 and r22 come together, and run it to the EL84 sockets on pin1? or do I replace the 100k resistors with the 1K?
Oh, and the screens on the Tube Town schematic are using a 1k/2w resistor, should I go woith the range 100 to 470ohm or stick with the 1k/2w?
Ive included the original Schematics for the Hammond organ amp, the power tubes use 6BQ5 there.
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Screen resistors are usually 100 to 470 ohms not 470K ohms. Typo? If you are using these values to reduce the B+ voltage they will overheat and burn. I suspect your donor power transformer makes too much voltage for your power tubes. However it might be suitable for 6V6GT???
Use separate 1 ohm resistors on each tube to measure tube bias. These numbers should be mv (millivolts).
Measure bias voltage where R21 and R22 connect to each other. This number should be volts
AC, help me to get this through my thick skull, Do I connect the 1K resistor(s) to the points where r21 and r22 come together, and run it to the EL84 sockets on pin1? or do I replace the 100k resistors with the 1K?
Oh, and the screens on the Tube Town schematic are using a 1k/2w resistor, should I go with the range 100 to 470ohm or stick with the 1k/2w?
I've included the original Schematics for the Hammond organ amp, the power tubes use 6BQ5 there.
All right, Duh, On the EL84 socket, pin 1 is just acting as a terminal point to connect to the resistor going to pin 2, so do I remove the existing resistor, replace with 1k, and then check the Bias voltage in mA at the junction of R21 and R22?
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In your effort to make the power supply voltages match the original schematic with no tubes installed you have really messed up the dropping resistors. I suggest putting the original resistor values back in and also removing that 20K that's between the diodes and the first filter cap. Then put the tubes in and connect the power cord directly to the wall. Your lightbulb is no longer needed. Now your power supply will have a proper load, and your voltage readings will be realistic.
All those voltage readings with the amp plugged into a lightbulb limiter and no tubes plugged in are really meaningless.
I agree with you, I've messed this up, my problem is this amp originally ran a 5U4gb rec tube which gave up the ghost, no telling how old it was, so I probably need to order another rec tube because the voltage is higher using the SS rectifier, which is where all my voltage problems are coming from, if I remove the 20 k resister the voltage will jump back up, so I guess Ill get another 5U4gb before I try this again?
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I think the drop you're expecting from the 5u4 is likely current based. Since your amp is only drawing a quarter of the rectifier's capacity, you may only drop 10-15V, compared to a perhaps expected 40-50V.
I may be wrong though.
What made you believe your rectifier is blown?
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I think the drop you're expecting from the 5u4 is likely current based. Since your amp is only drawing a quarter of the rectifier's capacity, you may only drop 10-15V, compared to a perhaps expected 40-50V.
I may be wrong though.
What made you believe your rectifier is blown?
The silver on top of the tube has "evaporated" for lack of a better word, it is gone, and the tube will not light up in the amp, or in my tube tester, which is a B&K 600 Dyna Quick, as mentioned was recently gone through, the man I bought it from was retiring, he replaced the resistors. I'm not familiar with the quality of the performance of this tester, my EL84s are showing 90 on a scale of 0 to 120, and pass a grid emission and short test.
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Please forgive my being overly cautious here, but Ive left the power caps the same for this test, will be changing them now, I did change the Screen resistors back to the schematic value of 1K/2W, the Grids back to 100k, but plugged straight into the wall here are the voltages at the moment:
PT:333 vac
Rectifier: 344vdc
Heater: 3.5 vac
EL84
Pin 2: -15vdc
pin 3:0
pin 7: +250vdc
pin 9: +233vdc
12ax7
pin 1: +14vdc
2: +0
3: +0
4: +3.5vac
5: +3.5vac
6: +24vdc
7: +0vdc
8: +1
9: +3.5vac
Phase inverter
Pin1: +34vdc
2: +17vdc
3: +23vdc
4: 3.5vac
5: 3.5vac
6: +33vdc
7: +33vdc
8: +23vdc
9: +3.5vac
from what I have read these numbers are quite a bit off,
All your help is appreciated!
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In your effort to make the power supply voltages match the original schematic with no tubes installed you have really messed up the dropping resistors. I suggest putting the original resistor values back in and also removing that 20K that's between the diodes and the first filter cap. Then put the tubes in and connect the power cord directly to the wall. Your lightbulb is no longer needed. Now your power supply will have a proper load, and your voltage readings will be realistic.
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AlNewman and Sluckey said it well.
Fix that power supply and remeasure voltages to start troubleshooting with good data.
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PAY ATTENTION! YOU'VE BEEN TOLD WHAT TO DO! MORE THAN ONCE!
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PAY ATTENTION! YOU'VE BEEN TOLD WHAT TO DO! MORE THAN ONCE!
You know I appreciate your knowledge of this subject, and that you share it so freely, but forgive me, I cant afford to replace components left and right so I am just trying to make sure I don't fry something, I was told there are no stupid questions, apparently that is not true, if my questions bother you please dont answer them.
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Guys I am sorry if I am redundant in my questions, I'm just trying to be sure I don't mess something up.
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All the power supply resistor values have been put back to schematic, JUST as a precaution I measured without tubes first,
P.T. 332vac
Rectifier: +449vdc
B+1: +450vdc
B+2: +425vdc
B+3: +357vdc
B+4: +348vdc
EL84
Pin2: -15vdc
3: 0
6: 0
7: +442vdc
9: +425vdc
12ax7
pin1: +361vdc
2: +0
3: +0
4: 3.5vac
5: 3.5vac
6: +368vdc
7: +0
8: 0
9: 3.5vac
Thank you
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I was told there are no stupid questions, apparently that is not true, if my questions bother you please dont answer them.
I mostly believe there are no stupid questions. But you have repeatedly ignored the good advice you've been given. I find that frustrating. If I had known this was where this thread was leading, I would have bailed a long time ago. Well, I'm gone now. I'll probably continue following this thread purely for my amusement. Be careful. Bye.
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With tubes in the screen and plate voltage still were +440vdc pins 1 and 6 on the 12AX7 was +357vdc.
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https://www.thetubestore.com/preferred-series-7189-premium-el84
Datasheet
https://www.thetubestore.com/lib/thetubestore/Preferred-Series-7189-Data-Sheet.pdf
Note, due to the internal connections at pins 1, 8, and 6, you'll have to reroute your screen resistors, and any other jumped connections from these pins.
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B+ is too high. What does it measure when you install a rectifier tube?
It appears that the AO39 power amp used a 5U4GB and two 6BQ5. It worked for Hammond. It should work for you. Hammond used 10 watt dropping resistors and two 30uf capacitors in the B+ feed.
Sluckey has been down this road. See his conversion!!!
https://www.sluckeyamps.com/hammond/hammond_ao39.pdf
The cap can next to the power transformer looks very old. Does it test good?
more conversion problems solved at:
https://sluckeyamps.com/index.htm
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The back-bias resistors in the Hammond power supply lower B+ by 28V.
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The layout indicates 9V caps in the Bias supply. Should be a minimum of 63V based on a calculated Bias range of -11VDC to -49VDC with a 25K Bias pot. Typo or problem?
Is the B+ high because there are no power tubes in or they are not conducting?
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The B+ is high because the transformer was designed for an organ. Organs have a massive preamp section which creates significant draw on the B+.
I tried to explain this 2 pages ago.
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The layout indicates 9V caps in the Bias supply. Should be a minimum of 63V based on a calculated Bias range of -11VDC to -49VDC with a 25K Bias pot. Typo or problem?
Is the B+ high because there are no power tubes in or they are not conducting?
Hello, The Caps in the bias supply are 63v, typo, The tubes test good, 95 on a scale of 0 to 120, emmission test is good, heaters are good, no shorts, (I have a tube tester) and it is a 50k bias pot.
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The B+ is high because the transformer was designed for an organ. Organs have a massive preamp section which creates significant draw on the B+.
I tried to explain this 2 pages ago.
Im sorry, I am new at this and taking in a lot of information, I am reading everything I can on this subject, and I am going to check out all the information all you gentleman have provided here! I really appreciate all the answers and comments, I am just learning this but I do feel im getting close here, thanks again everyone!
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B+ is too high. What does it measure when you install a rectifier tube?
It appears that the AO39 power amp used a 5U4GB and two 6BQ5. It worked for Hammond. It should work for you. Hammond used 10 watt dropping resistors and two 30uf capacitors in the B+ feed.
Sluckey has been down this road. See his conversion!!!
https://www.sluckeyamps.com/hammond/hammond_ao39.pdf
The cap can next to the power transformer looks very old. Does it test good?
more conversion problems solved at:
https://sluckeyamps.com/index.htm
My rectifier tube gave up the ghost, Have to order a new one, I will read through Sluckeys post and check out his site, the can cap does test good, probably would not hurt to replace it as it is old, on a slight budget here, but trying to pick up pieces weekly, It is the first of the week so I am not sun stroked out from my job, will cram all this info.
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The B+ is high because the transformer was designed for an organ. Organs have a massive preamp section which creates significant draw on the B+.
I tried to explain this 2 pages ago.
The OP keeps posting pin 3 is 0V. There is a 1R monitoring resistor. Is this a measuring error or is it really 0.000V? It should read 0.somethingV if the tubes are in. Is the meter on the right scale?
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The B+ is high because the transformer was designed for an organ. Organs have a massive preamp section which creates significant draw on the B+.
I tried to explain this 2 pages ago.
The OP keeps posting pin 3 is 0V. There is a 1R monitoring resistor. Is this a measuring error or is it really 0.000V? It should read 0.somethingV if the tubes are in. Is the meter on the right scale?
The meter may not have been on the right scale now that you mention that, it was on the 600vdc scale.
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New Rec tube is on the way.
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Ive got S Luckeys schematics printed out along with the original Hammond schematics from my old organ, I will study all this and try to figure this out, I really appreciate the help guys!
Oh and re tested the EL84s, they passed all the tests and on the "Quality meter" registered 100, My tube tester is a B&K Model 600Dyna Quick, prior owner said resistors were replaced (which I checked and they are new) and calibrated.
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And I did ask Sluckey if he minded that I study his schematics!
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Check your original Hammond Organ schematic to see if it had a second Power Transformer used for the preamp.
If it had two power transformers, the 140ma specification listed for the power amp power transformer may allow you to get B+ similar to the organ and similar to Sluckey's conversion.
If the organ had only a single power transformer it will not work with your plan.
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Check your original Hammond Organ schematic to see if it had a second Power Transformer used for the preamp.
If it had two power transformers, the 140ma specification listed for the power amp power transformer may allow you to get B+ similar to the organ and similar to Sluckey's conversion.
If the organ had only a single power transformer it will not work with your plan.
They have an extra input Tranny and output tranny for organ voicing but no extra PT, the PT and Rec tube itself was in a separate enclosure from the main amp.
I am re vising my plan at the moment, working towards using a 3 tube pre amp and a power section based on the organ power supply, this approach has been in the back of my head for awhile now, after looking at Sluckeys schematics it seems like the way to go, Ill have to replace some parts as I go, the 5U4GB rec tube should be here this weekend, and a new load of resistors, Ill keep going till I get it figured out with everyones help! Thank you!
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Have you figured out yet what your tubes are dissipating, or the current draw of your amp?
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Have you figured out yet what your tubes are dissipating, or the current draw of your amp?
Haven't got that far yet, not had a safe voltage for the tubes to run for any amount of time, Myself, being a noob at this, I don't know if you can or should run the plates and screens at +425vdc, was afraid of frying the screen, no body's really said if they will stand up to this voltage for any amount of time.
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Have you figured out yet what your tubes are dissipating, or the current draw of your amp?
Haven't got that far yet, not had a safe voltage for the tubes to run for any amount of time, Myself, being a noob at this, I don't know if you can or should run the plates and screens at +425vdc, was afraid of frying the screen, no body's really said if they will stand up to this voltage for any amount of time.
A JJ6V6S will handle those voltages.
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Have you figured out yet what your tubes are dissipating, or the current draw of your amp?
Haven't got that far yet, not had a safe voltage for the tubes to run for any amount of time, Myself, being a noob at this, I don't know if you can or should run the plates and screens at +425vdc, was afraid of frying the screen, no body's really said if they will stand up to this voltage for any amount of time.
Yep, If my new Rectifier tube and resister network don't do the trick, Ill up grade to the JJ6V6S
A JJ6V6S will handle those voltages.
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Hey Guys, My Rec tube will not be here until Monday, so I am going to re build the power supply, make a new board to mount the resistors on, I will get the schematic scanned in to photo shop and make it readable, if some one would check it out when I post it make sure I didn't screw something up, (I'm sure I will) once again, I really appreciate the help, all of you!