What to build with two 6V6GT's

[gayler]

Aside from the obvious, What other cool amps used two 6V6's? I just got an old Zenith chassis tha used those and a 5Y3GT, a 12av7, and some other tubes like 6av6 or something.I don't know what voltages the trany puts out yet, but was curious what else I might build with it. Thanks for all ideas!

[JoeM]

Tweed Harvard?

[imaradiostar]

Something similar to a Dr. Z Z-28. I'd use a 6au6 out front with much lower plate and screen resistor values. You won't regret it.

jamie

[gayler]

Is the Z-28 a fairly simple circuit? I want something pretty basic, but I'd also like something high gain. I know an oxymorron. Does anyone even have Dr. Z schematics?

[imaradiostar]

Basic but high gain...maybe try an Orange Tiny Terror? You could build one with 6V6's.

The Z-28 can only really be cranked for gain. It's more of a finesse/pedal amp. I would argue it's a far more useful amp with a few pedals than the Tiny Terror will ever be with or without pedals.

jamie

[Chuck H]

How about a TW Express type amp. Super simple. Plenty of gain. Does need to be cranked for disortion, but in my 20 watt amps I sometimes build in a simple but effective resistive attenuator.

It would help to know what kind of voltages you'll have. Suggesting a build based on power tube type alone is sort of like designing a house based on the water heater.

[imaradiostar]

How about a TW Express type amp. Super simple. Plenty of gain. Does need to be cranked for disortion, but in my 20 watt amps I sometimes build in a simple but effective resistive attenuator.

It would help to know what kind of voltages you'll have. Suggesting a build based on power tube type alone is sort of like designing a house based on the water heater.

I didn't see mention of whether or not the OP is an experienced builder. I'd hate to send him down the Ken Fischer path only to frustrate him when the circuit ends up oscillating or doing other crazy things.

That said, awesome suggestion. I haven't built a TW but I'd really like to. Too many projects.

jamie

[Chuck H]

True. And considering that he's working on an existing chassis that would certainly compromise layout. But what to build with only a couple of preamp tubes and a pair of little bottles??? The TW Express is RARELY used at max gain and even some KF built models that have aged now suffer instability when the gain is too high. If the OP wants a high gain amp from a conversion project He'll need to learn a lot about layout and grounding. That's certain.

[imaradiostar]

True. And considering that he's working on an existing chassis that would certainly compromise layout. But what to build with only a couple of preamp tubes and a pair of little bottles??? The TW Express is RARELY used at max gain and even some KF built models that have aged now suffer instability when the gain is too high. If the OP wants a high gain amp from a conversion project He'll need to learn a lot about layout and grounding. That's certain.

Which brings us back to a lower gain amp like the Z-28.

I wasn't crazy about my "z style" amps when I first built them but after spending some time with them I'm really convinced that every guitarist should own something similar- pentode or cascode out front, simple tone control, LTPI and quality output tubes.

It's not the heaviest sounding amp but they blend beautifully with a band and take pedals so well. I can get amazing crunch tones with any of a number of dirt boxes in front of mine- tube driver, fuzz face, ROG "thor", King of the Britons, and a Z-vex box of rock all sound amazing into one. I often use an attenuator and get that fabulous compressed slightly dirty sound that makes even the brightest of guitars sound harmonically rich. It's an incredibly rewarding amp to play.

What about something similar to your (Chuck's) El84 designs or maybe something with two cascaded stages out front into a LTPI and 6V6s? Maybe something simple with a treble roll off tone control?

I should really be asleep.

jamie

[Chuck H]

What about something similar to your (Chuck's) El84 designs

Flattering, but also layout dependant. And not un Trainwreck like. Which is a little troubling since I was protyping this circuit five years before anyone knew what the Trainwreck circuit was. It doesn't help that I DID take one good idea from the TW design and changed what was a local NFB stage to a cold clipping stage. Now my design and the Express share the same topology. I'm always worried that someone will take me for a cloner or a plagiarist.

Even a moderate gain amp needs to be pretty darned stabil if your going to overdrive it with pedals. I think we'll need some gut shots of what we're starting with and the plate voltages.

[gayler]

Not promising anything but I'll try to get some pictures and some voltages this weekend. I'm a little new to amp building as I've only built a 5F1 type amp so I want to try and stay simple. I maybe should have said moderate gain instead of high gain.

[imaradiostar]

If you want moderate gain why not build a marshall style preamp (2203/2204 style) into a fender deluxe reverb style output? It'll get to pretty high gain levels and could probably even do really crunchy metal with a boost in front of it. A little searching on the internet should easily result in a layout for a 2203 turret board.

http://metroamp.com/wiki/images/3/36/2203_MV_Layout.jpg

Like that!

jamie

[gayler]

Ok, no pictures yet. The power trany puts out 360 VAC or so on each leg and after the 5Y3GT I got 480 VDC. So at least I'm making some progress

[imaradiostar]

It'll do less than that under load but more with a Sovtek 5y3, GZ34 or solid state rectifiers. JJ 6v6's will take that voltage in stride. Try wiring up a basic cathode biased output section to see what real voltages would be like.

jamie

[gayler]

It still has the original Zenith branded 6V6GT's and GM/Delco 5Y3GT so I think they should live. What do most 6V6 based amps run for voltages?