7027's

[GenghisChron]

I have a few early 60's RCA 7027's that all tested good. Does anyone know of a good schematic that could utilize these? This will just be my second project, so I apologize if this seems trivial to you guys.

[KT66]

7027s are really just 6L6s, except that pins 5&6, and 1&4 are connected internally, so you could use them in any circuit that takes 6L6s - just remember not to use the normally unused pins on the tube sockets as tie points unless you want lots of smoke. Here is an article that goes into a little detail about this : http://www.triodeel.com/7027.htm

[paulster]

The correct answer, notwithstanding the evidence presented above, is an Ampeg of course!

[KT66]

The correct answer, notwithstanding the evidence presented above, is an Ampeg of course!

Of course that is what first comes to mind, but maybe something like a V2 as a second project might be a bit much . Although, if you go that route, here is a guy you can get the 6K11 socket from : http://pacifictv.ca/socket.htm#compactron

[selloutrr]

V4
VT-22
VT-40


Hands down the "TONE" for 7027s

[paulster]

That's exactly what I was thinking!!

[KT66]

V4
VT-22
VT-40


Hands down the "TONE" for 7027s

Mark, are you saying that you don't subscribe to the 6L6 theory ? Don't get me wrong, a DIY V4 would be kick-ass, I've never seen one. A bunch of the parts, like the panel, etc you can get at http://fliptops.net/ , and there are a few Ebay sellers that have that duodecar 12 pin socket cheaper than the link I posted above.

I just think the OP might be better off doing something simpler, like an AB763 type thing, or an octal Rocket. If you check out the Trainwreck discussion Gehngis there is a lot of info about that, like these threads for example : http://ampgarage.com/forum/viewtopic.ph ... er&start=0

http://ampgarage.com/forum/viewtopic.ph ... erb+rocket

[selloutrr]

I've rebuilt about dozen V4 / VT22 / VT40 series ampegs and service regularly 35 more. They are not an easy amp to work on but they are the "TONE" of the 7027 tube for guitar amps.

The 7027 tube can work in place of a 6L6 as long as you mod the circuit to except it. I haven't noticed a benefit in using the 7027 in place of a 6L6, since the 6L6 is a cheaper easier to replace tube.

IMHO the fender circuits, were not very impressive with a 7027 though very easy circuits to build.

I'll have to dig up my template and pics of the restoration of a couple V4's I had one come in that was burned up on the inside and had to strip the boards and fabricate the PCB from scratch using the old one as a guide. I've offered it to fliptops several times but due to the amount of board tweeks and revisions ampeg did to the V4 series he didn't feel it was worth stocking. I've also rebuilt two V4 on turret boards, lots of under board jumpers but it turned out to be a very reliable setup.

I'm not sure the V4 is a good pick for a first time build the voltages are high and circuit is rather in depth. If you want to hear what a V4 (vt40 - 4x10" combo) sounds like cranked up and cocked back with a Wah listen to Queens of the Stone Age or Kyuss.

[paulster]

I've rebuilt about dozen V4 / VT22 / VT40 series ampegs and service regularly 35 more. They are not an easy amp to work on but they are the "TONE" of the 7027 tube for guitar amps.

This is probably why you can't find one outside of SoCal then! The desert/stoner rock scene just loves these amps, and with good reason.

I'm not sure the V4 is a good pick for a first time build the voltages are high and circuit is rather in depth.

Yep, I'll definitely agree here. It's a complicated build with very little support available in terms of layout, experience with these amps (other than basic repairs and your own), the high voltages, and a couple of funky tubes to boot. Lead dress around the Compactron could be a challenge for a new builder too. It would be a great achievement though.

If you want to hear what a V4 (vt40 - 4x10" combo) sounds like cranked up and cocked back with a Wah listen to Queens of the Stone Age or Kyuss.

Or for the other end of the tonal spectrum the Rolling Stones around the Exile timeframe when they were using V4s as well. Completely different, but equally awesome, recorded guitar tones.

[jaysg]

I don't see why a 450V V series amp in a heavy aluminum chassis with power scaling, wouldn't sound good. Custom PT from heyboer and you're there. I believe Andy Fuchs has a midrange inductor for sale. The rest can all be done with 12ax7 and 12au7 tubes, so you don't need to worry about 12dw7s and the compactron.

Alternately, please send me all your 7027a's. They're a terrible biohazard and should be disposed of by a professional.