Opinions on a 5E3 - too loud, decreasing headroom

[belf]

I have had a new 5E3 build for a few days now and even though I'm pleased with the nature of its sound, there's 1 aspect that's killing it for me: It is very loud for home use. So I get nice break-up only when it's really loud (that's on the 2-3, guitar volume control halfway through). What do I really want ? Dirt, minimized headroom. On V1 I'm using a 12ay7. I tried and didn't like a 12AX7 on V1.

The speaker I'm using is a brand-new Jensen P12R, sensitivity-rated at 95db.

So, after some initial research, my options are : VVR, Attenuator or less efficient speaker.

What do you guys think ?

I think a VVR is relatively inexpensive to build, so I'm willing to build one. Though I think perhaps I could achieve a lot with a less efficient speaker. Could you recommend one ?

Cheers

[tubenit]

Dana Hall's VVR is easy to install and inexpensive. You could also use a PPIMV  (post phase invertor master volume).

http://www.el34world.com/Forum/index.php?topic=6899.0

You can try a 5751 in V1.   Ironically, I usually see people asking how to increase headroom on a 5E3.

With respect, Tubenit

[belf]

Ironically, I usually see people asking how to increase headroom on a 5E3.

I know, it's quite ironic. I really love the sound but I really feel it in my belly, if you know what I mean.

You think the VVR (or the Master Volume) is a better solution than a less efficient speaker ?

[tubenit]

You think the VVR (or the Master Volume) is a better solution than a less efficient speaker ?

Yes, I do!  And much less expensive. I personally would probably add a PPIMV.

You could also try 6K6's in the amp if the plate voltages are around 300v? Of course, with the VVR, you can get the volts down to 250v for a 6K6.

Another option is to use a 5751 and simply parallel the V1 tube for 30% more gain with little to no increase in floor noise.

With respect, Tubenit

[belf]

Understood ! Do you recommend building one myself or getting a kit like https://www.grangeramp.com/ppivmv_kit.php ? Actually, taking a look at your other thread, you built a VVR and not a PPIV Master Volume on your 5E3, is that right ?

[Platefire]

I've built several 5E3's over the last few years. My last build just recently finished, I did away with the extra channel and just did a one channel with the bright channel tone stack. I added the pre-PIMV and a hot switch using the 12AY7's extra gain stage that normally supports the other channel.

1-Pre-PIMV(with the hot switch off)-This works good for getting more breakup and sensitivity at a lower volume. The only catch to that is as you turn the pre-gain up and turn the MV down you begin to loose the bottom punch that the power tubes contributes and even though you can get a nice grind with the pre-gain cranked way up and the MV way down--it's a little hollowed out an mushy at the most extreme settings with the power tubes mostly dialed out. With the MV at 100%(full volume) it's more or less as if you have no MV and the pre-gain operate like a normal 5E3 volume. This is your cleanest sound and would be handy if you ever play in a larger room and need more headroom. With the this pre-PIMV there are some very good usable sounds in between cleanest and most extreme.

2-Hot Switch Mode---The good, bad and unstable  

Bad--It has it's good points and bad points. With the pre-gain cranked up past 2:00 the amp becomes unstable sound-wise and starts motor boating. Also with the tone control past about 2:00 with the pre-gain that high you get a squeal from the tone stack. You can correct this by simply backing off slightly until it quits. The vol and tone settings are usable as long as you stay away from past 2:00 oclock range. There are measures/modifications you can take to reduce gain with the hot switch stage to fix this but so far I haven't taken these measures and choose just to use the usable area of adjustment from 7:00 to 2:00 on the pre-gain and tone. I'm still expermenting with this.

Good--With the pre-gain set a slightly above 7:00 oclock(barely on) and the MV full up, I get a very bottom heavy crunch that's very defined and not sloppy. This is blow out the walls power cord stuff that has a good sound but is very loud that is controlled by the pre-gain and is very touchy because the slightest movement clockwise increases the volume much. But as far as a heavy rock sound it is great but from a practical side of controlling volume, not practical for bedroom practice.
  From this point you begin to turn the MV down and increase the pre-gain for lower volume playing. As already mentioned in non-hot switch mode, as you begin to turn the MV down and pre-gain up the sound is good as long as there is an element of power tubes still engaged and are pleasing tones but the more
preamp gain involved and less power tube--it starts to get mushy in the extreme settings.

General Conclusion. Both modes work best IMHO by strongly using your guitar volume to go between clean and OD/distortion. With the hot switch off, you can get some good clean tones when backing of your Guitar volume but in hot switch mode those clean sounds are harder to find even when you back off. I'm mostly a clean player so the hot switch off is more usable to me. If you like more distorted tones and don't need a truly clean sound to back off to, the hot switch mode would probably work for you.  

This is just sharing a little of my latest 5E3 experience That may or may not be useful. Hope you can get it working like you want. Attached is the schematic.  Platefire

EDIT: I modified PPIMV in this post to read Pre-PIMV now that I understand the first "P" in PPIMV is    post and not pre. I do feel that my description above is pretty accurate maybe more on the positive side rather than negative on how the Pre-PI MV works on the 5E3. IMHO it's better with the Pre-PIMV than no MV at all and when you turn that MV up 100%, it's like it's not there and operates like a normal 5E3.

[belf]

Thank you very much indeed for this very detailed information, sir. I'm going to open the .sch as soon as I'm home, can't install stuff at work due to government policies 

[eleventeen]

Yeah, the NSA is into death metal.

[tubenit]

Do you recommend building one myself or getting a kit like https://www.grangeramp.com/ppivmv_kit.php ? Actually, taking a look at your other thread, you built a VVR and not a PPIV Master Volume on your 5E3, is that right ?

You don't need a kit. Just buy the 250k dual gang pot and two 2.2M resistors (and any wire or shrink tubing you'd need) from Doug.

I've never owned or built a 5E3.  I have used VVR in 4 or maybe 5 different amps?  I've used PPIMV in quite a few also. I like both.

With respect, Tubenit

[Ed_Chambley]

Do you recommend building one myself or getting a kit like https://www.grangeramp.com/ppivmv_kit.php ? Actually, taking a look at your other thread, you built a VVR and not a PPIV Master Volume on your 5E3, is that right ?

You don't need a kit. Just buy the 250k dual gang pot and two 2.2M resistors (and any wire or shrink tubing you'd need) from Doug.

I've never owned or built a 5E3.  I have used VVR in 4 or maybe 5 different amps?  I've used PPIMV in quite a few also. I like both.

With respect, Tubenit

The 2 resistors (2m2) can be small like 1/4 or 1/8 watt.  This helps give a little extra room on the dual pot.  Really helpful if you find it necessary to use shielded cable.  I always use the shielded since I have had problems with noise.  Lots have just twisted wires and report working well, but I have not been that lucky.

[phsyconoodler]

A regular post phase inverter master won't work on a 5E3 cause of its type of phase inverter(split load). I find master volumes on the 5E3 suck bad.
   Build a nice attenuator.The one I build has two switches: one for a 6db drop and the other for a 12db drop.Very transparent sound. Google attenuator layout and look at the 'guitar player version' that was submitted by Gerald Weber.Works great,far better than an L-Pad type or just about any of the commercial ones I've tried.

[tubenit]

 

regular post phase inverter master won't work on a 5E3 cause of its type of phase inverter(split load).

My understanding is that a 5E3 has a concertina phase invertor.  My understanding is that Divided by 13 uses something like a PPIMV on
one of their amps that has a concertina phase invertor?  So IF that is correct, maybe some individuals like the PPIMV on that type of phase invertor?

http://www.dividedby13.com/cj11.html

I will state that typically I don't like a PPIMV dialed below around "4-5" range. It sounds somewhat weak below that. So maybe that is what Physconoodler is referring to?  However, I don't like a VVR below 4 either.

OK, I did a search to see if anyone had done a 5E3 Deluxe with a PPIMV and found this  "I have the LarMar PPIMV with dual 250k on my Deluxe and it works perfectly and I use it all the time FWIW."

With respect, Tubenit

[darkbluemurder]

A PPIMV can be used on a concertina/split load in the same way as with a long tailed pair after the PI output couplng caps. No difference at all. I have a LarMar PPIMV in 5 homebuilt amps, 4 have the long tail, one has a direct coupled concertina. Works well in each and every one.

Cheers Stephan

[sluckey]

Split load = concertina = cathodyne. Just different names for the same circuit.

[Ed_Chambley]

regular post phase inverter master won't work on a 5E3 cause of its type of phase inverter(split load).

My understanding is that a 5E3 has a concertina phase invertor.  My understanding is that Divided by 13 uses something like a PPIMV on
one of their amps that has a concertina phase invertor?  So IF that is correct, maybe some individuals like the PPIMV on that type of phase invertor?

http://www.dividedby13.com/cj11.html

I will state that typically I don't like a PPIMV dialed below around "4-5" range. It sounds somewhat weak below that. So maybe that is what Physconoodler is referring to?  However, I don't like a VVR below 4 either.

OK, I did a search to see if anyone had done a 5E3 Deluxe with a PPIMV and found this  "I have the LarMar PPIMV with dual 250k on my Deluxe and it works perfectly and I use it all the time FWIW."

With respect, Tubenit

I have used this on numerous amps including 5E3.  I prefer it to a VVR.  I do however prefer it with a triode switch on a 5E3. Then I have a lower volume clean.  I like a linear dual pot.  Reducing the .1 coupling caps is necessary IMO to keep the woofey tone away.  The master is sort of funky in the stock circuit and goes from very thin to overly bassy very easily which makes it seem as if there is not much useable adjustment.

[Platefire]

I guess I'm getting confused on terms. I thought a PPIMV was a pre-phase inverter Master Volume---does that actually mean "Post Phase Inverter Master Volume"? If so what is pre? Platefire 

[sluckey]

I guess I'm getting confused on terms. I thought a PPIMV was a pre-phase inverter Master Volume---does that actually mean "Post Phase Inverter Master Volume"? If so what is pre? Platefire 

PPIMV = Post.

Pre would be a simple volume control connected in the grid of the phase inverter.

[Platefire]

Thanks! Don't want to belabor the question but if the acronym for post is PPIMV what is the acronym for pre? MV? yes I'm hard headed   Platefire

[sluckey]

Marshall JCM-800 2204 calls it "Master Vol"   

[Platefire]

I give up   

[Ed_Chambley]

Some call the pre master GAIN just to complicate things more.

[sluckey]

Actually Plate, I had the same question about PPIMV 10 years ago when I got back into this stuff. That is a relatively new acronym. I don't recall any such thing back in the '60s and '70s. Marshall and Fender both had a MV and they were both before the PI. So, is PPIMV pre or post?

Well I found out just as you did. I asked on AGA and some smart ass (like me   ) came along and told me.

Thru the years the use of the MV has kinda changed. Today it's all about getting grind by running preamps and PIs wide open and cutting the drive just before the power tubes. And I came to realize the PPIMV was better suited for that than the old style MV.

We didn't really need any MV back in the '60s cause we ran everything wide open any time we could get away with it.    

[Platefire]

Now that I know that PPIMV is post and not pre, I guess the only amp I got that has it is an Allen Accomplice that works really well but is a modified one channel AB763 without vibroto and raw added. We are talking 5E3 here but I was pretty happy with the regular MV on the Hoffman Record Player project. It may not meet everyones criteria of what they expect out of a MV but IMHO it's a lot better amp with the MV as oppose to having no MV at all. Platefire

[1rebmem]

I'm wondering what his plate voltages are? And if lowering them will yield the result he is after.
Maybe a different rectifier tube to lower B+?  Don't know what he is using currently.
I just tried different rect tubes in my 5E3 and a NOS RCA dropped B+ which gave lower volume and earlier break-up.

Perhaps using zeners to lower B+ ??  No drilling the chassis this way and cheap.

Am I off base?

[Willabe]

I'm wondering what his plate voltages are? I just tried different rect tubes in my 5E3 and a NOS RCA dropped B+ which gave lower volume and earlier break-up.

Perhaps using zeners to lower B+ ??  No drilling the chassis this way and cheap.

Am I off base?

Not off base at all, very good question, IMO.

Using zeners to drop B+ is usually a last resort.


            Brad     

   

[phsyconoodler]

Ok.Still,a Lar-Mar master volume will not work on a 5E3.I also have put a master volume on amps like a Princeton Reverb and a 5E3 and they sound hideous to me.Hence my use of the two step attenuator.
  We went through the master volume for the split load PI in the past and you cannot wire it like a conventional master for a long tailed pair PI.

[belf]

ok, i just took the plunge and ordered a 250k dual gang pot  I will keep you informed ...

I'm going to measure the B+ when I arrive home...so I measure DC on pin 8 of the rectifier tube to ground ? All controls maxed out ? Stand-by switch on the amp doesn't work...


By the way, anyone knows of an extensive document with voltages listed for different test points ?

[tubenit]

Hoffman has a voltage chart.  There are several 5E3's on that list. Look at their voltages.

http://www.el34world.com/charts/valve/ValveDataIndex.php

Short version is you measure B+ nodes,  plates and cathodes as a starting place.

With respect, Tubenit

[jjasilli]

1.  Less efficient speaker:  2 or 3dB difference is equivalent to doubling (or halving the) the power of the amp.  But power is logarithmic, and goes by factors of 10.  A mere factor of 2 is barely noticeable.  Not likely to solve your vol. problem.

2.  The 5E3 is a very simple amp.  There's very few spots to generate overdrive, so power tube distortion is a must.  IMHO this rules-out a MV for this amp.  I realize that others may heartily disagree. But for me, MV is appropriate for modern amps with more complex preamps in which all the overdrive tone you want can be generated there; then only a clean boost is needed by the power amp to drive the speaker.  A 5E3 is not in that category.

To me, this leaves 3 choices for a 5E3: a pedal in front of the amp; VVR; or an attenuator after the amp.

[Platefire]

Good thing about this thread is I'm learning more about MV's than I ever knew before. I've been putting MV's in a lot of old builds because I just really like them--so I'll be looking closer at PPIMV's now than ever. With a dual gang pot in the same 1M MV hole and a little re-wiring, wouldn't be too hard to get there. Platefire

[SILVERGUN]

belf,,,,please don't let me distract you with my questions, but I had an idea while reading over your thread, that relates to a recent experiment that I was trying by reducing the gain in the phase inverter.......conventional wisdom says "get the most output power from the fewest parts for the least amount of money", BUT if we're not concerned about getting max power for the buck than it might make sense to lose power where we would normally be trying to make it.....

So guys,,how about increasing the value of the cathode resistor on the PI to reduce the gain to significantly less than unity gain?
Kinda like the 18 watt "power dampener" (LTPI) switch in sluckey's scrapbook.....will that work Ok with the cathodyne PI?...just as a fixed value of lets say 4.7K or as high as 10K?.....it might actually cause a little bit of "favorable" clipping  

OR

Another idea would be to replace the 12AX7 in the V2 position with a 12DW7 as a "plug and play" mod that he could switch out when he wanted full volume....so he would retain the 12AX7 triode as the pre PI gain stage, but have the 12AU7 triode as the PI.....

OR, a combination of both ideas?

Obviously we would have to make sure that his pin-out matched up for using the DW7, BUT whadda ya think?.......(there's always that reverse 12DW7,,,the JJ ECC823 if his pins don't match up)

belf, I can't say I have tried either of these ideas,,,but I have tried the "power dampening", and it does lower the output volume of the amp and changes the response of the PI...good or bad would be for you to judge...
the 12DW7 is a unique "special design" tube that houses a 12AX7 in one half, and a 12AU7 in the other half.....the 12AU7 has an amplification factor of 20 compared to the 12AX7 of 100

***now that I have read jjasilli's post,,,I would like you to know that my ideas would be reducing the chance of output tube distortion......so it might be a cool idea to also switch to 6K6GT's (as suggested earlier by tubenit), which are a lower wattage output tube, and a little easier to overdrive, that also seem to break up sooner than the 6V6***

[sluckey]

So guys,,how about increasing the value of the cathode resistor on the PI to reduce the gain to significantly less than unity gain? Kinda like the 18 watt "power dampener" (LTPI) switch in sluckey's scrapbook.....will that work Ok with the cathodyne PI?...just as a fixed value of lets say 4.7K or as high as 10K?.....it might

I think that will be futile. First off, if you need significantly less than unity gain, you would use a voltage divider, rather than a choked gain stage. But, anytime you take an output from the cathode of a gain stage that output will be slightly less than the input regardless of the value of the cathode resistor. Well, within reason. I'll bet you could go from 10K to 500K without changing the output signal voltage on the cathode. But there's another factor too. The plate resistor must be the same size as the cathode resistor if you want to have equal signal levels to send to the PA.

You have an amp built up on your breadboard, right? Take a few minutes to replace the PI with this 5E3 PI and tinker with it.

But really. My 5E3 is a loud amp. Way too loud to get that overdriven sound in my house (except when I'm home alone). I think an external speaker attenuator is gonna be the best bet for this amp in the bedroom.

[SILVERGUN]

First off, if you need significantly less than unity gain, you would use a voltage divider, rather than a choked gain stage..

So, in this case, maybe just a pre-PI master like in the Hoffman "Devinator" that Plate posted above?........but wouldn't the choked gain stage possibly "reduce headroom"?

anytime you take an output from the cathode of a gain stage that output will be slightly less than the input regardless of the value of the cathode resistor. Well, within reason. I'll bet you could go from 10K to 500K without changing the output signal voltage on the cathode. But there's another factor too. The plate resistor must be the same size as the cathode resistor if you want to have equal signal levels to send to the PA.

good lesson.....I was taking some of my "idea" from Merlin's page, and just wasn't seeing the whole picture....he does talk about balancing:
http://www.valvewizard.co.uk/cathodyne.html

How about the 12AU7 triode suggestion,,,how does that affect the gain of the PI?.....I realize it changes the "personality" of the amp

You have an amp built up on your breadboard, right? Take a few minutes to replace the PI with this 5E3 PI and tinker with it..

That's a great next step, because Jack Hester's version of the amp on the board has this PI, so that tinkering will be dually beneficial....it's just that I'm at such a great point with this current experiment, that I can't turn around just yet......guess I have to build another one 

I think an external speaker attenuator is gonna be the best bet for this amp in the bedroom

I agree, but just wanted to throw a possibly different approach out there in hopes of learning something new,,,and I have 

belf,,,here's a common attenuator plan, as created by Gerald Weber....as suggested by phsyconoodler above 
I built one and I "like" it, for certain situations......maybe yours

[sluckey]

How about the 12AU7 triode suggestion,,,how does that affect the gain of the PI?.....

The gain of the cathodyne, split load, concertina, (or whatever else you may want to call this circuit) is FIXED at slightly less than 1. There's no way to get around that fact. Anytime you take a signal output from the cathode that signal amplitude will ALWAYS be slightly less than the input signal at the grid. Sure, you can supply more current, and drive a lower impedance load from the cathode, but the signal voltage will be slightly less than the grid signal. Tube type, resistor values, supply voltage, none of that matters.

[SILVERGUN]

The gain of the cathodyne is FIXED at slightly less than 1. There's no way to get around that fact.

There it is...now I get it...I was reading into the statement "The main drawback of the cathodyne is that its gain is limited to slightly less than unity to each output"

...and thinking limited meant MAX, and that there would be a way to reduce the signal to MIN with component or tube variations 

Sorry to detract from your thread belf  .....I had to learn that sooner or later....public schooling can be embarrassing 

[belf]

So, here are the voltages, do they seem normal ?:



I did some comparisons and doesn't it seem weird that I ve got voltage on only 2 pins on the rectifier ? Perhaps I've measured something wrong...

[belf]

The gain of the cathodyne is FIXED at slightly less than 1. There's no way to get around that fact.

There it is...now I get it...I was reading into the statement "The main drawback of the cathodyne is that its gain is limited to slightly less than unity to each output"

...and thinking limited meant MAX, and that there would be a way to reduce the signal to MIN with component or tube variations 

Sorry to detract from your thread belf  .....I had to learn that sooner or later....public schooling can be embarrassing 

No problem, i'm always happy if a discussion helps other people as well !

[SILVERGUN]

Just for the record.....you could do an even simpler version of that attenuator I posted and eliminate 1 switch and 2 resistors if you wanted to settle for a "single stage" attenuator,,,meaning you would just switch in one set of 2 resistors, and have only one set amount of attenuation...

There's also this, if you like modern technology and have room for a 12" speaker:
http://www.eminence.com/pdf/maverick.pdf

[belf]

I'll probably build the attenuator as well....and a tube screamer ts 808 :) The eminence could possibly do what I want......only problem is that I'd have to buy it without testing it first and then all the hassle to send it back in case I don't like it. Thank you for pointing it out though, I'll keep it on my watchlist. Any comments on the voltages ?

[sluckey]

I did some comparisons and doesn't it seem weird that I ve got voltage on only 2 pins on the rectifier ? Perhaps I've measured something wrong...

You have to switch your meter to measure AC voltage to get the readings on pins 4 and 6.

[belf]

ok, pins 4 and 6 on rectifier 324 VAC....

[belf]

Comparing my 5e3 to an original 59` found here http://www.el34world.com/charts/valve/ValveData.php?e=view&f=14613

it seems that the voltages are fine...

[Platefire]

I checked my 5E3 voltage readings with yours and yours are about 10VDC above mine across the board but I would say your voltages are good. Platefire

[belf]

Yesterday I recorded a short video to demonstrate the hissing when turning the volume knob past 1 or 2. Dialing the tone knob back a bit makes things slightly better, but the hissing's still there. Is that normal ? Isn't it hissing too much ?

https://www.youtube.com/watch?v=BYI_41DYOh0

[SILVERGUN]

Yes, it does sound like too much noise....I would suggest starting a new thread so you will get more/new attention to your new concern.

[Willabe]

Probable noisy tubes.


         Brad