Guys, how do you do?
This is my first post. I wish I could colaborate with this forum.
I`m building a Masco MAP15 Clone, you know, the combo, but in a head way.
I have been reading some stuff, like the paper of Gerald Weber about harp amps, and Randy`s article that`s here: Lone Wolf Blues Company 6L6SE Amp Project

I`m thinking about making some mods to the amp.
Listen it.

YouTube - MASCO MAP15 GUITAR
YouTube - MASCO MAP15 HARP

Schematich
http://img257.imageshack.us/img257/3774/mascomap15.jpg

Some Photos:
http://img837.imageshack.us/i/p1020020.jpg/
http://img821.imageshack.us/i/p1020019v.jpg/

Now, I`m working on this mods.

1. Lower the gain of the first stage.
I think it`s not necessary, they are low enough
ImageShack® - Online Photo and Video Hosting

2. Replace the power supply filter caps and increase the values.

3. Replace coupling caps with harp friendly caps.
I`m using .01uF, is that right?

4. Change the bypass cap of the cathode resistor. I`m using 10uF with 220ohms, what do you think about 33uf?

5. Mod of Weber: waveform non-symmetrical with a Pot

6. Connect the speaker reverse polarity with respect to which half of the waveform is bigger

Well, thanks a lot, actually i apreciate you spending time in this post, and giving your advice.

Thanks,
Santiago.