Davis 201-A Donor amp - Suggestions Please?

[statorvane]

I've been on a SE amplifier kick for the last several years and am turning my attention back to push-pull amplifiers. I acquired a Davis 201-A PA amplifier a few years ago, with the intention of cannibalizing it for a guitar amplifier. It has an (advertised) 20 watt power section, and three 6EU7 preamp tubes (low noise 12AX7s).

My intention is to turn this into a 15-20 watt push-pull guitar amplifier. There are a lot of possibilities in this power range:

• 20 Watt Marshall - based on PA amplifier
  18 Watt Marshall variations (Superlite TMB, Lite II B, 1974, TMB)
  15 Watt Liverpool
  15 Watt Rocket
  Matchless Spitfire

My intention is to give this to my son. He plays through a JCM-800 clone (doesn't use anywhere near the available power) and a Fender FM 212. Ideally he'd scrap the FM 212 and use this instead. He likes effect pedals; wah, leslie simulator, chorus, flanger, ring modulator(s), fuzz, various overdrives - you name it he's got it. My guess is the pedal friendly amplifiers would probably be one of the 20 watt Marshall PA variations, or the Rocket.

Did I miss anything? What amplifier would you guys suggest if you were in my shoes? He's mostly in to classic hard rock and old-school metal. I occasionally hear him playing Tool riffs too.

Thank you kindly.

BTW, here is a link to some info on the Davis 201-A: http://www.sotxampco.com/Schematics/JW-Davis/201A.pdf

[martin manning]

Lots of options. Maybe you can enlighten the lad to the sound of pure tube distortion if the power level is low enough to run it cranked up. I can't get my Marshall Studio 15 away from my son... that's another circuit you could do, BTW, and you have enough preamp tubes to do more than one.

Interesting and fun document on the PA amp, thanks for posting it.

[Leo_Gnardo]

I'd put those 6EU7's aside & build with 12AX7 or its relatives. So you or Junior can easily substitute pre tubes in the future. Also 6EU7 are getting rare and expensive. You'll have a couple EU's on hand in case you run across some old EU-equipped Gibson or similar amp or tube Echoplex. Or $ell 'em off to someone who does need 'em.

[dorrisant]

Yep... Dump the 6EU7s like Lou said.... Build a Hoso56! It has the range of tones your son would find very useful. I'm totally digging mine right now!!!

[Stevem]

X3 on ditching the eu7s !

[Phil_S]

I think I'm going to buck the group on the 6EU7's. They are identical to the 12AX7 in spec, but different pin out. I guess you could say they are like the 7025. Anyway, none of that matters. What's wrong with giving the "good stuff" to your kid?

I tend to use what I have on hand. Nothing lasts forever. What's the point of trying to prolong forever? I might go deaf in old age and be stuck with good sounding tubes I can't hear. When 6EU7's get too scarce, you can easily rewire for 12AX7's. That goes for the current build as well as the old Gibson you may or may not ever own.

Just my 2¢.

Good luck with your build. You've got lots of great choices. I'll put in a bid for a Marshall TMB-18W. It has the normal channel with one tone and one volume, and the TMB channel. It's two flavors in one box. You can do it with whatever power tubes you like.

[martin manning]

I think Leo's point was that there would be lots of options available for tube rolling with a 12AX7 pin out. Those 6EU7's might sound really good, or they may be spent.

[Phil_S]

I think Leo's point was that there would be lots of options available for tube rolling with a 12AX7 pin out. Those 6EU7's might sound really good, or they may be spent.

Yes, that's a really good point. Of course, I'm assuming the 6EU7's are still good and not everyone has a stash of tubes for tube rolling.

[Stevem]

Well also some of the new ax7s are also made with a nice quite spiral wound filament!

[Structo]

Man, I wouldn't hesitate to build him a Tweedle Dee.

To me this amp sounds more Marshall than anything Fender.

You can easily tweak the values to your son's taste.

Some people scoff at a 15-20 watt amp, but these hot rodded deluxe amps are pretty darn loud.

[Leo_Gnardo]

I think Leo's point was that there would be lots of options available for tube rolling with a 12AX7 pin out. Those 6EU7's might sound really good, or they may be spent.

X-actly, thanks Martin!

[statorvane]

The amp's last gig was as the house PA at a local American Legion - probably for the last 40 years or so. I'm sure the power tubes and rectifier are worn out. My son and I fired it up when I first got it a few years ago, and the sound wasn't great. We popped in some new Sovtek EL84s and there was a definite improvement, but we didn't have a rectifier tube to swap so couldn't really judge the preamp tubes. The B+ was lower than shown on the schematic. A friend of mine has tried them out for me in an amplifier he has and thought they were fine. I'll just go ahead and give them to him. I will probably just use the transformers from the amplifier.

Thank you all kindly for the suggestions. We pretty well have the Marshall territory covered here, so I was thinking about a 15 watt Liverpool or Rocket; something with a Vox vibe. Curious about the Hoso56 though. I'll have to check it out.

Yes, these 15-20 watt amps are perfect for the basement. My last two amplifiers (Single Ended) are around 20 watts:
http://s165.photobucket.com/user/JKCavi ... t=3&page=1
http://s165.photobucket.com/user/JKCavi ... t=3&page=1
The 50 watters we have...
http://s165.photobucket.com/user/JKCavi ... t=6&page=1
http://s165.photobucket.com/user/JKCavi ... t=3&page=1
are way over the top!

Thanks again.

[zozoe]

Got it,, I think

[statorvane]

Here you go. Hope this helps.

Davis 201.pdf

FWIW I found the PT produced ~300 VDC. I built a clone Marshall 2061X using the OT and a spare Hammond PT. I still need to build a head cab for it.

[zozoe]

Greetings all~ I've been scouring the web & the chats for a Schematic for my Davis 201-A amp, but I'm striking out, & would greatly appreciate a hand and a link that still works.
Thanks in advance, & be well~