For those who dig this stuff: my YGM-3 chassis, before & after

[Jon Silberman]

Before:

http://pic10.picturetrail.com/VOL326/682310/4310808/53859630.jpg

After (note especially added bias trim pot to left of middle blue cap):

http://pic10.picturetrail.com/VOL326/682310/4310808/53757980.jpg

The beautiful work (as always) is by Pete Cage. Large replacement caps are LCRs, smaller ones are Sprague Atoms. New resistors are a variety of Ohmites and ceramics. With bias pot added and adjusted to taste, V+ = 410, Vp = 406, Vg = 18.7, lk = 24MA avg., Po = 22W @ 8 ohms.

More on this "new" amp of mine to follow in the Amps section in a few days time. :)

[JohnnySavant]

What EL84s are you using that can take the voltage?

[Jon Silberman]

JJs.

The voltage now is actually considerably lower than how the amp came stock.

[kevmin]

Yeah, I retubed one of those with Russian output tubes. The paint on the tubes was brown within seconds. Lots of heat... The adjustable bias is a good idea.

[Jon Silberman]

The amp shipped out to me with Sovtek EL84s. It sounded awful, no power and distorted. When Pete checked 'em out, one was shorting and the other weak. The choices were clear: NOS Philips (max headroom/power handling) or JJs (bang-for-the-buck current stock). I went with the JJs, I'm tired of spending big bucks on NOS tubes, my new motto is the "95% rule" - if it gets me 95% of the way there, it's enough.

[Jon C]

JJs are excellent IMO, they made my Blues Jr. come alive and sound great in the Bad Cat Cub.

JC