Matchless Lightning?

[chuckb]

Hey Guys, I'm looking at building another Matchless Lightning clone using the Ceriatone layout. I would like to use 6v6's instead of el84's and was wondering what changes would I have to make in order to accomplish this? I have attached the layout that I have already have done. Any help would be greatly appreciated.

Chuck.

http://www.ceriatone.com/images/layoutPic/matchlessLayout/Lightningceriatone.jpg

[chuckb]

anyone?

[Jazz P Bass]

Have you done your homework?
What is the heater requirements of a 6V6 compared to a EL84?
Is the present transformer sufficient?
What is the effective ac plate resistance of a 6V6 compared to a EL84?
Will your output transformer match up?
What are the bias requirements of a 6V6 at the plate voltage you have?
See where I am going with this?

[chuckb]

hey jazz p bass, yes, I hear ya, point taken. Homework!

[chuckb]

I'll just stick wth el84's, the transformers I have are new matchless trannys with a 6.3CT/4A hearter winding,5V/3A winding and a 564 CT/.08A. The out put tranny is 4,8,and 16 ohm tap with 4k ohm B+voltage. So I figure 6v6's would be no provlem for these trannys.

chuck.

[trevorus]

I have done some conversion work on a Valve Jr, and putting a 6V6 in was relatively easy. Just do a little homework. 6V6's and EL84's need similar signal levels to drive properly, so it's not a tough one.

[chuckb]

hey trevorus, I went ahead and used el84's as the layout called for but I'm not liking the brightness of this amp. I want to cut down the brightness and the volume as well. The amp is super loud for fifteen watts. I can barely touch the vol control and it's loud, I would like to tame this high volume as well as the brightness.The amp is really to clean and sparkly for my tastes. when the vol is turned up past 6 I get a god overdrive/tube saturation though. Any suggestions on how to tame the brightness and less vol on lower setttings?

Chuck.

[trevorus]

Take that 100 pf capacitor off of the volume control. That should tame the brightness a bit. You could also make it switchable. As far as power goes, you could add a triode mode switch that would drop the power down to about 5-7 watts. That would definitely drive earlier, and at less volume. That will change the tone a bit, though.

[chuckb]

Hey Trevorus, yes, i'll remove the cap from the vol pot and see how tah works, I coulda triode mode switch, athough my experience with cutting the power in half diffinately kills the tone.

Chuck.

[pdf64]

A 5Y3 rectifier (old production / USA made) will bring the VB+ down some and so will reduce power output significantly. But even a few watts is freakin loud in a domestic situation!

[Chuck H]

6V6's and EL84's need similar signal levels to drive properly

Huh? IMHE 6V6's need as much as twice the drive voltage as EL84's.

[olddawg]

You might want to talk to the posters on 18watt.com. They have a couple of layouts there for 6v6 complements and several amp builds.

[chuckb]

Yes, thanks olddawg,I'll check it out. I did use the el84's for the lightning build as per the schematic. I do have another set of 15 watt Matchless tranny's though and I would like to explore the idea of a build with 6v6's. Thanks guys for all your replies,much appreciated.


Chuck.

[trevorus]

Huh? IMHE 6V6's need as much as twice the drive voltage as EL84's.

I stand corrected. Sorry 'bout that.

[Chuck H]

I stand corrected. Sorry 'bout that.

Well, it's different strokes more than anything. Many EL84 amps drive the grids TOO much. A swap without changing grid drive would probably yield very acceptible results going from EL84's to 6V6's. Going the other way may well be way too much drive though.