$200 6V6 Amp

[greenvalve]

I was going to enter this amp in a $200 6V6 listening competition but they do not allow Ebay parts source.

So, I thought I would post the schematic here for your amusement. I have not built it yet.

[Geek]

I have a client that swears by 6V6's as pre tubes and I respect his tastes

Cheers!

[greenvalve]

Yes, many who like pentode drivers say that the 6V6 is excellent, but I have not heard it myself.
Other good 'multi-grid' drivers (used triode strapped) that I like are the 6E5P and the directly heated 46.

[Miles Prower]

Originally Posted by greenvalve

I have not built it yet.

That's a good thing. The Walton-Cockroft is a bad choice for a voltage doubler. The W-C is half wave circuit, which means DC through the secondary. This is highly likely to cause core saturation. The W-C is useful when the current demand is much lower, and when you can use it with a gapped core xfmr (think CRT flyback xfmrs here). That should be replaced with a full wave doubler.

[ErikdeBest]

Originally Posted by Miles Prower

That's a good thing. The Walton-Cockroft is a bad choice for a voltage doubler. The W-C is half wave circuit, which means DC through the secondary. This is highly likely to cause core saturation. The W-C is useful when the current demand is much lower, and when you can use it with a gapped core xfmr (think CRT flyback xfmrs here). That should be replaced with a full wave doubler.

I don't understand it. To me the original schematic is based on a full wave doubler, at least it is exactly like this schema (last schema on the page)

but, if it is not, I can explain it by the fact that it is almost two in the morning

[greenvalve]

Could be, but I don't think so. It's nearly a cut and paste from PSUDII... Notice the ground connection, I don't see DC. But if Mr. Prower says its there it must be... please explain! The only place that DC could be dawn is off ground, not through the tranny, no? This is Greinacher topology not WC.

[rdf]

Don't you find the 6V6 too microphonic for an input tube?

[greenvalve]

Originally Posted by rdf

Don't you find the 6V6 too microphonic for an input tube?

I wouldn't know, I've never heard it I spend most my time with DHT.

[Miles Prower]

Originally Posted by greenvalve

Could be, but I don't think so. It's nearly a cut and paste from PSUDII... Notice the ground connection, I don't see DC. But if Mr. Prower says its there it must be... please explain!

A full wave doubler should look like this



If that's how it works, then it'll be just fine. Don't use PSUD-II, as I do designs the old fashioned way: with a scientific calculator, and so am not familiar with the effffffffffffffff-up ways PSUD presents schemos.

That thing still looks like a W-C, and is very confuzzling.

[greenvalve]

Sorry Miles, I'm self taught and sometimes my schematics are from Mars I get that all the time! Your inquiry is very much appreciated! I'm glad there is no smoke (yet).

And happily, I have been able to source all the parts from NON-Ebay vendors, so its a go! And here is the updated schematic, still under $200!


Take a guess how it'll sound, I haven't a clue! I'm thinking maybe a little distortion cancellation of 6V6 driving 6V6 and stunning detail. If microphonics is a issue I'll adjust the driver circuit for a lower loading of 6K.



http://greenvalve.wordpress.com/file...atic.jpg?w=560