favorite old gear to buy for parts

[eleventeen]

Is there a good reason to take that apart if 98% of the value is in the tubes that just yank out?


You should probably buy more 214A's, put the glunky tubes you get in them, and relist them. Move them units, LOL.


I once bot a $10 Tek scope that was loaded with 6DJ8s but 3/4 of them tested very weak.

[Paul1453]

It appears there is not much interest in HP 214As.   

They are quite old.  The 1st one had most of it's cap cans sitting on broken insulators.

It is quite easy to just pull the tubes though.  I couldn't get to 1 6DJ8s without removing the big clunky switch.
Once I get to tearing things apart, I guess I just get a little carried away.
I will probably not strip this one naked like the last one.

The chassis does seem to be a decent platform for a rack mounted guitar amp.

Did the low testing 6DJ8s not sound good?  My 12AX7WAs tested low but sounded just as good as my Mullard or Bugleboy.

[eleventeen]

I have no piece of audio gear that uses 6DJ8s and you are correct, they are more or less 12AU7s which are sub-useful, gainwise. I just one day found myself with a dozen or so 6DJ8 and decided to test them all on my (now ill) Hickock 600. So I have no way to report on audio performance. I think I had 6-8 6DJ8 that were 30-40% = very sketchy. *And* uneven. The stinkers were real stinkers.

[Paul1453]

My tester is a Heathkit TC-1 which even using the TC-2 tube listings doesn't show tester settings for most of the tubes in the 214A.   

It does list settings for 12AX7s.  My 3 tubes tested remarkably balanced.  5 readings were like 39, 6th reading 40.
My other 12AX7s test closer to 50, but when I put the WAs in my K10, they all sounded great.

You wouldn't happen to know where I can get settings for more tubes for my tester would you?
If not, I'm thinking of just listing some of these with returns accepted.
Let the buyer try them out and if not completely satisfied just pay to ship them back for a full refund.

I'm pretty confident in the quality of the parts HP used in this gear.   

I found a better settings list for my tester.  It had settings for 6922/6DJ8/ECC88.
I had 12 tubes, from PQ Amperex 6922 with gold pins to Sylvania 6DJ8s.
All tubes tested well balanced, and the range was only 38-42 for all 12.
Most tested 40/40, worst 38/40, best 40/42.  Pretty sure this means all are good to go.   

Still can't find tester settings for the PQ 7534s. 
Data sheet shows those are powerful audio tubes.
The pair is capable of 60W output!

[Paul1453]

Only selling 2 tubes from my hockey puck analyzer has netted me a profit and lots of free high quality parts.

Maybe I should just focus on scavenging parts to resell at a profit and use those profits to buy pre-made amps.   

Naah, I am actually enjoying myself rekindling my old electronics training learning more about guitar tube amps. 

[Paul1453]

Another HP 214A?  Really   

After selling off a few tubes to net my costs,

Free high quality used HP parts can't be beat!

It does take some work, but it is worth it to me.   

[Paul1453]

Are some of you lurkers starting to bid on HP 214A's?   

Up to this point I was usually the only bidder on these items.   

I couldn't blame you if you are, the 214A does have an impressive lineup of tubes and assorted parts.   
But it is definitely not a guitar amp in disguise.

Some people think they can still get a lot of money for these.  I don't see that happening.
I just wait for them to get tired of relisting their item and finally price it to go.   

[Paul1453]

Any feedback on my latest purchase?

Hammond big iron on sale.   

Here's what I make of this item.

1 beefy PT.
2 PP 20+W OTs for EL84 or 6V6 amps.
1 PP 30+W OT for 6L6 or some kind of Bass amp OT?   

The questionable OT is being driven by 2 7591s at +400V to an 8 ohm speaker.
It is labeled Bass amp and has 130 ohm coils on each side of the CT.
7591 data sheet shows 6.6K plate load at 400V for 32W output.
Any idea if this is OK for 2 6L6s?
If not, any suggestions for what it might be used with it besides the 7591s?
I saw 6GM5s listed as a 9 pin equivalent of the 7591.  I don't think I have any of those either.
I'll have to double check my tube inventory.  LOL

PS.
I think the seller has 1 more of these available at the BIN price of $29.95   
With my sale he sold 3 of these in the last 24 hours.  They are going fast.   

[PRR]

> Hammond big iron on sale.

Just so you know: I think Hammond Organs and Hammond Transformers are totally different companies.

[HotBluePlates]

Here's what I make of this item.

1 beefy PT.
2 PP 20+W OTs for EL84 or 6V6 amps.
1 PP 30+W OT for 6L6 or some kind of Bass amp OT?   

Stereo.

The EL84 OT's are for left & right of the stereo spectrum. I've not had one of these amps but I'll venture a guess these OT's are small for their power through-put. That's because there's no low end for either the left or right channel being passed through them... That's been shaved off by the 3 C-R (high-pass) filters between the input jack and the 7199 pentode driver of the output stage.

The bass for both left & right channels is passed through 3 R-C (low-pass) filters between the input jacks and the 7591 channel's pentode driver. The bass-only sound is amplified and applied to a much bigger OT for connection to the woofer. This works because bass is generally omnidirectional, which is why stereo mixes evolved to sitting the bass right in the middle of the stereo picture... If you have any deep lows, it doesn't convincingly sound like it's coming from only the left or right speaker (and also why you have a single subwoofer speaker in a modern stereo setup).

Any feedback on my latest purchase?

It would seem a shame just to rip it apart. You never wanted to hear your tunes through a tube stereo? All you need are the speakers, tubes and a check that electrolytic caps are still good... Then verify you have or can make all needed power supply voltages.

7591 data sheet shows 6.6K plate load at 400V for 32W output.
Any idea if this is OK for 2 6L6s?

7591 is a 19w 6L6 in a 6V6-sized bottle, with a much-twitchy-er gas pedal. Has ~70-80% higher Gm, so it take less drive signal and bias to make its output power as compared to the 19w 6L6.

7591's used to be $75-80 a bottle; now there's new production as cheap as ~$18/bottle. Or you could ebay them & find some on occasion for less. Switching to 6L6 means bias supply re-design and possibly an added gain stage or changed/redesigned inverter to give them sufficient drive to produce low end to match the EL84 channels. Buying some 7591's is the shorter path to joy.

[Paul1453]

My first inclination when looking at this was to keep it all together as a stereo amp, but then I considered not having all the necessary tubes and a speaker cab with the 3 speakers, so I then evaluated just the transformers instead.  I concluded that the transformers alone were worth considerably more than I had to pay, so I pulled the trigger.   

I have a need for at least two EL84 PP OTs for my current stock of premium tubes.
I don't want to kill any more little unknown wattage OTs, and only have 1 PP OT I'd like to reserve for my breadboard set up.
I don't think that OT could handle 2 6L6s, so the Bass amp OT seemed like it might be a bonus item.

I have at least two extra PTs in stock that would easily work with the EL84s.
I hoped I could use this beefy PT and unknown OT to make a PP 6L6 amp.

I did read something about this particular Hammond model having some failure issues.
Is this really a shame to part this out to make 3 amps instead of 1?   

[Paul1453]

> Hammond big iron on sale.

Just so you know: I think Hammond Organs and Hammond Transformers are totally different companies.

Yes, I think you are correct about that and everything else you post about tube gear!   

Hammond Organs did use quality transformers that were designed and matched well with their output tube circuits, correct?

With so many people converting Hammond Organs into guitar amps, I'm guessing these transformers work well for that?

[sluckey]

There is no PT on the AO-70 chassis.

[Ed_Chambley]

> Hammond big iron on sale.

Just so you know: I think Hammond Organs and Hammond Transformers are totally different companies.

Yes, I think you are correct about that and everything else you post about tube gear!   

Hammond Organs did use quality transformers that were designed and matched well with their output tube circuits, correct?

With so many people converting Hammond Organs into guitar amps, I'm guessing these transformers work well for that?

Usually you will find Inductor (Choke) inputs on organs and organ cabs.  This will give you a voltage multiplier of .08 to 9.  Also it makes for much smoother DC and will make for a very different Guitar amp.  If you are looking to build a very clean Guitar amp this is a good way to go.

I have one which I used 12Ax7 to a 12aU7 PI and 4, 6v6 tubes from a JR20 Tone cab.  Hooked up to a Hepner 12 AlNico sounds very much like a Standel.

[Paul1453]

There is no PT on the AO-70 chassis.

Really?  I see four transformers.
Three OTs and a Choke then?
Then the big black one is for the 7591s?
I think you are correct in that PS components are labeled 7xx and power amp 3xx.
I'm having a hard time locating that (choke) on the power amp schematic.

It's all good.  I happen to have an excess of PTs at this time.
So I have a PT for each proposed amp already in stock.

[Paul1453]

There is no PT on the AO-70 chassis.

You are correct, Sir.   

This shows a more complete setup, and that really is a beefy PT.   

[Paul1453]

So, if I have a 7199 for V305 I'm thinking I can check channel A's amp by:

Lifting C329, attaching input jack to R350 + C330.

Use my Bench PS to provide the +310, +300, and +275 to the circuit.

Attach 8 ohm speaker to channel A output, and strum away.   

Similiar setup for channel B.   

If I had some 7591s, I could check bass amp by:

Lifting R406, attaching input jack to C364 + C365.

Use my Bench PS to provide the +400, +350, and +305 to the circuit, with -24V attached to the bias circuit.

Attach 8 ohm speaker to bass channel output, and strum away.   

If that all worked it might be rather simple to chop this up into 3 amps.   

[sluckey]

The choke is not on that partial schematic you posted. The choke is the plate load for the reverb driver. There's a lot of other stuff on the chassis that's missing from your partial schematic. You can find a complete schematic by searching for Hammond H100.

[Paul1453]

So far my Google searches have only come up with a zip file that has those schematic segments.

I did look at each page, but I guess I missed that choke.  That is OK.

That one segment contains the important power amp info I needed.

I am hoping that choke will also be adequate for a low amperage PS design.   

The main parts I wanted were the two EL84 PP OTs.  The rest is icing on the cake.   

[sluckey]

This is on the same page as the partial schematic you posted. I used that same choke on my Plexi6V6. There's still a lot more stuff on that AO-70 chassis that's not shown on your schematic. And a lot of the stuff that's on your schematic ain't on that chassis. But if all you want is the iron, it really doesn't matter. A tube set for that chassis would be expensive. And that still doesn't have a power supply.

[Paul1453]

Great! and thank you.

The choke goes in the +1 column, and it appears the bigger black OT will work for a pair of 6L6s.  +2 

I think I will try to test the EL84 circuits as outlined above, if I can find a 7199 in my tube inventory.

I am interested to see how that single 7199 tube pentode/triode configuration sounds as a guitar amp.

Maybe it just needs a 12AX7 with tone stack added to the front of this circuit to be more guitar friendly?   

[Paul1453]

Another HP 214A?  Really   

After selling off a few tubes to net my costs,

Free high quality used HP parts can't be beat!

It does take some work, but it is worth it to me.   

Well the HP 214A came through for me again.

It was loaded almost exclusively with HP labeled Amperex tubes made in Holland this time.   
Selling off just the 9 6DJ8s should net me nearly double my costs.

Everything else are free parts then, including the 3 HP labeled Amperex made in Holland 12AX7 tubes.
The cheapest listing for I could find for one of those was BIN at $57 including shipping.   

About the PQ 7534s otherwise known as E130Ls, does anyone know of an audio amp circuit for these?
I have been searching for one, but so far have come up empty handed.
They are 10,000 hour audio tubes capable of 60W output for a pair.
The Ebay market won't pay me half as much for one of these as it will for a 12AX7.
So with 4 of these PQs and the other 2 being Mullards I'd like to find a design to use them in.
It could be a stereo Hi-Fi design if that is the best use for them.
I can't see listing these tubes multiple times just to get $15 a piece for them.

[Paul1453]

Back to the Hammond now.

No wonder all the tubes were pulled from this.

The 7199 is out of production, 7591s are very expensive, EF86 same, only EL84s are still reasonably available.

I don't have any 7199s, but have read the 6GH8 and 6AN8 are subs with the proper pin reassignments.

I have at least 1 6GH8 and a few 6AN8s.  It seems some HiFi'ers prefer the 6GH8 over the 6AN8 as a sub.

All seem to say to pay the price for the 7199s if you can still get them, as they sound much better than the subs.   

Now it seems the only economically feasible use of this Hammond is to chop it up and redesign for more readily available parts.

Would any of you experienced members think it is worth my efforts to sub in the 6GH8 to test the EL84 circuits as they are?   

I'll end up chopping up these EL84 circuits anyway because I don't have enough subs for the 7199s.
I'm pretty good at tearing things apart, putting them back together is another story. 
I'll be going to a more standard 12AX7, 12AT7, 12AU7 well-known preamp design. 
At least, these tubes are widely available at reasonable prices.

[Paul1453]

I guess when it rains it pours. 

Poor seller should have set a reserve or higher opening bid.   
I hope he doesn't try to cancel the sale.   

Obviously two different Hammond PP OTs.

This should satisfy my lower wattage PP OT needs for a while.

Unless, of course, I can get more of these for less than $4 a piece including shipping.   

[Paul1453]

No complaints from the seller and marked as shipped. 

For only $.01 I might have had compassion on this poor seller and let him out of the deal if he had enough.

He will definitely get positive 5 star feedback from me!   

[Paul1453]

Decided to pick up a 7199, since I got it for less than a 12AX7.

Much easier to just plug this in than try to pin swap for a sub.

I definitely will try the EL84 circuits as they are before any disassembly now.

I am very interested in how they sound.  Clean with lots of headroom, is cool.
Adding a pedal or two to the input is an easy way to get the sound you want, in that case.
Much easier than redesigning the circuit to get that sound, IMO.

[TIMBO]

Hi guys, Still a lot of great old stuff out there.
Never thought I'd see another one (or two)of these.



These old "PYE" TV's were in just about every home in Australia and as a lad (around 1968)spent my share of time holding the spiral antenna trying to get some sort of watchable picture. We had four stations with one of these you could only get if you lived on top of a hill.
Lots of mustards, but not the usual guitar type. Good PT. Small OT, couple of watts. Decent choke. Another transformer that is marked as "VERTICAL OUTPUT TRANSFORMER" don't know if it is useable.
I can see where the local amp builders got there tubes.
6CM5
6BL8
6DX8
6BM8

[Paul1453]

Nice!

The best thing about something like that is people will sometimes just give it to you.
They know that a TV like that is not worth fixing.

Bogen has some PAs that use the 6BM8.
I think the 6CM5 can also be used as an output tube. 
The little OT will work with it's current output tube.
If your vertical output transformer is like the one I have it is 1:1.5 windings.
Maybe useable in a reverb/tremolo circuit?   

No Marshal stack conversions here, but many parts for a simple bedroom amp.   

[PRR]

> "VERTICAL OUTPUT TRANSFORMER" don't know if it is useable.

A V-sweep circuit "is" an audio power amplifier. It has to cover 50Hz-5KHz so the picture looks OK, and typically does a bit better; half to several Watts depending on the CRT size.

Main question is the output impedance. Sweep yoke impedances didn't come standardized like speakers; often the yoke, V-sweep, and H-sweep parts were made and sold as sets. Measure turns ratio. That paper tells what tube is the V-sweep output. See if the impedance into available speakers works out anywhere near reasonable.

There's obviously a speaker amplifier on there, but I don't see the tube type.

"6CM5" is better known as EL36. Also EL6 (diff base) and PL36 (diff heater).

[TIMBO]

Hey PRR, The small sound output transformer was connected to the 6DX8 and applying 9.6v to the primary gave me a Z of 3600. I don't know what the speaker ohms was but with an 8ohm load would work with the 6DX8, 6BM8 ......
I was looking to use these small transformers for reverb drivers with tanks that have 8ohm inputs.
The VOT has a few wires attached.
Blue orange and red have continuity with 121ohms between red and orange and 397ohms between orange and blue.
Applying 9.6v to blue and orange as these were connected to pins 7 and 6. The only reading I get is on the short black and orange of 1.4v.
Going off the tube chart the 6BM8 is the vertical output tube. 

[Paul1453]

My Hammond organ chassis and the other OT order came in.
I actually got 3 OTs for $.01 in that deal.   

I'm waiting for the 7199 I ordered to come in to test the 2 EL84 circuits as the are.
The guts of it look clean, no obvious burnt or removed parts.

I'm gonna pull the big black OT, test it manually, and then find a simple PP 6L6 circuit to try on my breadboard.

[Paul1453]

How about a simple mod project?

Says it's a working 12AX7 driving 2 EL84s PP OT for I'm guessing 12-15 Watts output power, AM/FM tuner amplifier.

A simple modification to the Phono or Aux jack input should turn it into an AM/FM tuner / guitar amplifier.   

For less than $40 including shipping I have a hard time making myself not buy these items.   

More of my items will need to get listed on Ebay before this weekend, to more equally balance the flow of funds before my wife gets mad.   

[Paul1453]

Selling a pair of tubes that covers the last purchase should keep the  to a minimum.   

Buying good deals and selling items at a considerable profit keeps my junk gear enterprise rolling along.

Building a nice inventory of cheap/free high quality used parts to use in my projects.

I still need to make some profits to spend on some tools.
Drill press/bits, saws and other wood working items.   

[Paul1453]

How about a simple mod project?

Says it's a working 12AX7 driving 2 EL84s PP OT for I'm guessing 12-15 Watts output power, AM/FM tuner amplifier.

A simple modification to the Phono or Aux jack input should turn it into an AM/FM tuner / guitar amplifier.   

For less than $40 including shipping I have a hard time making myself not buy these items.   

Well, the AM/FM tuner appears to be out of alignment, but I didn't buy it for that anyway.

The PP EL84 output section works very well.   
No major hum or other problems noted.
The Bass and Treble pots seem to have a nice effect on the tone.
I used 2 adapters, 1 stereo to RCA and the other to convert to 1/4" plug.

When I come in through the tape port, the signal goes through a 6AU6 to the 12AX7 to the EL84s.
Very similar to the Bogen K10, with what seems to be a better tone stack and a little more output from the 6BQ5s compared to the 6AQ5s.
The seller had listed his tube tester results for all the tubes in this.
The 6BQ5s appeared to be significantly mismatched, so I swapped in a closely matched pair of Channel Masters from one of my other junk gear purchases.
Sounded pretty darn good like that, but swapping the 12AX7 for one of my premium tubes made it sound even better.
Next I need to find one of my Mullard 6AU6s to swap in.   

It has a switch for internal and external speakers, or external only.
It didn't come with an internal speaker, and it appears to like the external speakers as 2 x 12 at 4 ohms over 1 x 12 at 8 ohms.
With some preamp line and gain boost added into the tape input she really shines, for a low watt amp.
With the boost and internal volume dimed she sounds great, with a nice sounding easily controllable feedback available by pointing the guitar at the speakers.   

Now for my dilemma on what to do with her.   
I could purchase the Photofacts service manual/schematic for this.
It is Montgomery Wards Airline Model WG-2661A, if any of you have access to that schemo and wouldn't mind sharing it with me.   
I would appreciate that greatly, otherwise my searches so far have come up empty and I'll need to purchase it.

I'm pretty sure I could follow the service manual instructions to re-align the AM/FM tuner.
It's been about 25 years since I have done that type of thing, but I do have experience with this type of procedure.
The question is "Is it worth it?"  Do you think someone would pay more for a low watt guitar amp with a built in AM/FM tuner?

Otherwise it would be simple enough to:
Change tape input to 1/4" jack
Make a speaker cab to mount this in
Mount a 1 x 12" speaker I already have
Remove the tuning dials/display and pot
Remove function switch, leaving On/Bass Treble and Volume pots out front
Guitar input and speaker output jack with internal/external or external only speaker switch would be on the side of the amp

I think just mounting this in a decent cab with a 1 x 12" speaker would make this a $250+ value amp.
I'm not sure anyone would be willing to pay significantly more for an aligned AM/FM tuner with switchable functions on a home guitar amp.   

What do you guys think?
Just make a guitar amp, or get the service manual and make all the features function properly again?   

[Platefire]

The Hammond PR-40 Tone Cabinet is a treasure trove of speakers, vintage hook up wire, tubes, transformers, cab parts and all kind of miscellaneous parts. I've had two. It had three EL84 push pull amps in it. One I got for free and the other I paid $20.00 for. Believe it or not, one I made an interface for and used it for a guitar practice amp for a couple of years--big practice amp. After I finish having my way with them, parted them out. I'm presently selling the last of the parts on e-bay including the interface I made. One or the PT's and choke is going on my present Plexi project. Platefire

BTW- Here is a pix of the interface I made to hook my guitar up to the PR-40. It's made out of an old battery charger and supplies fused AC power to the PR-40 and power switch to turn it on and off plus preamp input jacks that goes G1 and G2 Grids all through a 5 pin female connector to the Pr-40's Power Supply chassis.

[Paul1453]

It really wasn't a difficult decision on what to do with the Airliner.
With todays technology someone could just use an adapter to connect their Ipod or smartphone to play their tunes or radio on it if they really wanted.
Actual value perceived added by realigning tuner = 0.  Cost of Photofacts is > 0.  Realignment procedure is a NO GO.   

Have any of you considered adding an Audrino card to your tube amplifier circuits. 
That could add Bluetooth connectivity and possibly signal processing effects if designed properly.   

This thing actually sounds really good.  The bass and treble pots can have a dramatic effect on the quality of the sound output.
I currently have this hooked up to my computer for listening to music and Youtube videos.
Listening to a talk show, you can really improve the quality of the audio with these tone controls.
Even when the recording qualities are poor you can adjust the tone to closely match how you know that persons voice sounds.

With a guitar, just a little level/gain boost is needed on the input to really rock out. 
This one is a little cleaner and louder than the K10.  The K10 doesn't need any boost on the input to rock out.
I've got the Airliner currently driving 3 Peavey 12" guitar speakers, and it sounds rather impressive for a bedroom amp.
I am quite pleased with this Airliner!  Now to spend some time designing and constructing a decent cab for it.
A single 12" speaker will be what goes in the cab with it.   

[Paul1453]

I guess I needed to climb up on a hilltop to really see all the territory I've gained.   

A picture is worth a 1000 words, see below.   

Looking over my captured territory, I need to see if I have the proper wells for my houses, and where the outhouse's need to be placed to not contaminate any of the wells.

This all makes much more sense if you are hip to PRR's house plumbing analogy for guitar amps.   

I really don't need to gain any more territory until I have completed building some houses with the proper plumbing.   

The Bogen K10 and the Airliner are both working fine, and will be kept as test bench reference amps.
The circuits for these are quite similar except for the output section.
It looks like I may already have most of the parts I need to make two more of each of these.

The other two are much different.  A simple 12AX7/6AQ5 SE output conversion.
On the other, I'd like to use that Hammond organ chassis as my platform for a 6L6 PP output circuit.
I'm not really sure what to go with on that, and am strongly leaning towards buying a turret board from Doug on this one.
I'd like to try at least once to make a nice cleanly laid out amp that looks as good inside as it sounds outside.
If I could learn to build them as nice and clean as mscaggs, I might think I'd have died and gone to Heaven.   

I need some metal and woodworking tools to really make good progress .
The crappy SS 10W conversion works as it is now, but those tools would allow me to finish it up right.
I checked a local Pawn shop for things like a table saw, a drill press with good bits and some clamps and other junk amp housings and speakers.
Maybe when I get paid I can try to get a package deal on those items, and anything else that is needed to help me fully finish a few amps. 
It's one thing for me to have an open amp sitting next to me on my bench to play when I want.
It's another thing completely, for me to sell an amp like that on Ebay to some young and dumb guitar head
that might have little children running around.  I've got to encase those potentially lethal voltages in something before I can sell it with a clear conscience.

Behold, a portion of the territory I've captured is displayed below.   

[trobbins]

Timbo, was the 6DX8 used for SE power amp stage?

I found a nice radiogram with a chassis just for power supply and stereo 6DX8 PP - that chassis converted very nicely.  A control panel strip also provided a 12AX7 and 6N8.

[TIMBO]

Hey Tim, Yeah the 6DX8 was the sound output and the 6BM8 for the vertical output.

[trobbins]

Ok, so it would be a single ended output stage.  Interestingly the recommended SE and PP stage output transformer loading are both about 16kohm.  Could make yourself a nice midget 1-1.5W bedroom amp!

[Paul1453]

It's not like I really need another project to work on.   

I just cannot pass up what I know to be a good deal on Ebay.

So, for $60.07 delivered I picked up a "working" Wurlitzer Model 7011 organ amp.

Here's what the seller had to say about it:
This is a vintage Wurlitzer 7011 amplifier out of a model 4602 organ.
This amplifier was working when it was removed last year from the organ.
This amp has 2 6L6 tubes, 1 5U4G, 3 6SN7GT, 1 6SL7GT, 2 6SQ7.

I paid $40 for a new pair of Peavey 6L6GCs before.
With a 5U4G and 1 6SL7GT that should pretty much assure I got my $60 worth in tubes alone.   
I don't have any 6SL7s and am interested to hear how they sound after hearing many good reports about them.

If it proves to be in working condition, it should not be too big of a project to convert it into a guitar amp.

[sluckey]

The guy you bought the AO-70 from now has the matching power supply listed...

http://www.ebay.com/itm/Vintage-Hammond-H100-Series-Organ-Power-Supply-/121872907690?hash=item1c6030fdaa:g:kuEAAOSwLnlWonkc

[Paul1453]

Thanks

It might have been useful to me if I was actually making an organ.   

I've got the thing stripped.  I've made a Hoffman Stout with one of the OTs on my BB.

Almost ready to put that in a real chassis now.

And I just finished making a Wards Airline design PP 6L6 amp on my BB with the bigger OT.

It's working but I'm not sure this is the design I want to build in a chassis yet.

I've got another similar PP schematic that is negative voltage grid biased I may have to try.   

Luckily I've got a few PTs from my other junk buys that will work for the 6L6s.

This one is really big iron and expensive to ship.

[Paul1453]

Well I did it again.   

I didn't need another project but for $63.15 delivered how can I pass this up. 

4 Vintage 6V6GT tubes, and what looks like 2 5U4 tube rectifiers to me.
Just those tubes pretty well justifies my purchase price.   

My K10 might sell locally for $200 this week.
And I hope to have a bare chassis Hoffman Stout ready to go by this weekend.   

[Paul1453]

And again?   

A Bugleboy rectifier tube, a 12AX7 that looks like it has the premium X on top, 1 blown 6BM8 and 1 good?, a PT, OT, a reverb tank, and free shipping for $60???

 Done!

 I think I have at least one or two of those 6BM8s in my tube stash.

 I'm praying some of my amps start selling soon, Please God?

 I do get the pay after delivery which gives me another two weeks before I really have to pay.     

[eleventeen]

This was quite an excellent score at the local e-waste place. $40.


Entirely unmolested Voycall model 25KR PA amp. Original, clean, with cage with just some minor chassis gloin, little tranny rust. All RCA tubes, RCA 6SJ7 *2 and two RCA Blackplate 6L6GC! Prelim research says the amp wants a 5V4 versus the 5U4 that is in there. S'OK. As yet untested. Just got it home in exactly this condition. Very cool.


I was a bit hesitant but when I turned it around and saw those RCA 6L6's there was nothing further to think about.


One wonders: The front panel with the tone controls and the metal plates with the legends, that looks 30's-40's. Looks pretty cool, too. Indeed, the stencil around the 6L6 tubes says "6L6G". So why am I finding 30-40's front panel styling; 6SJ7 tubes (late 40's-50's) and yet 6L6GC? Probably all the tubes were replaced in this with RCA's shotgun style sometime in the mid-60's.

[Paul1453]

Indeed, a very nice score!   

Those 6L6s were probably replaced at some time.

My 6L6Gs are a different shape from the GB/GCs it appears you have in there.

If it is older, then it was probably built with 6L6Gs.
These have the same specs as the metal 6L6 as far as I can tell, and can't take the higher voltages of the newer ones.

If your plate voltage is like +380 or a little less than even the metal 6L6s can go in there.   

Really nice score!  A few simple mods into a Rocking guitar head, and I'd guess it would be worth at least $300 to someone.

[eleventeen]

Yeah, you can see the metal 6SJ7s and 6L6's in this example. Not pretty! http://www.radiomuseum.org/r/voycall_amplifier_25dr.html


Yes, 6L6G's are bowling pin shape; they can be large or small. I have a pile of NOS JAN Sylvania 6L6G. The 6L6GCs are worth as much or more than the amp to fetshists. Untested. My Hickock tester is on the fritz.


Other than bring it up slowly on a variac, I have to decide what to do with this. I will replace the 5U4 with a 5Y3 to get a 2 amp rectifier instead of a 3 amp one in there and keep the B+ lowish while I test it out. Fortunately electronics has a way of waiting patiently. It's really pretty clean, I don't want to ravage it. OTOH, it's not like a '57 Strat.

[Paul1453]

Yes, the metal tubes look rather industrial.   

But in a circuit designed for the 6L6G,
I cannot hear any difference in the metal, Gs, or GCs.   
The metal ones are significantly cheaper to replace.   

[eleventeen]

You're actually making the same very good point I think I made to you; on general principles, it's better to do whatever I'm gonna do to this with old but good 6L6Gs I have lying around instead of the GC's. Just in case something blows and takes out a tube. I even have metal ones.