OT - Revised Firefly Chassis Layout

[Paul Marossy]

OK, I revised the Firefly chassis layout to show connections for a 6.3V heater supply and correct connections to the 12AU7. I also removed the resonance control because it doesn't seem to do anything the way it was shown. If someone can tell me how it should be connected to the circuit, then I could give it a try and report back.

http://www.diyguitarist.com/PDF_Files/FireflyChassis.pdf

I think this is fixed now. I did this here and there while at work. A second set of eyes would be helpful.  

(I know it still says "w/ Resonance Control" at the upper left had corner, I'll remove it later)

[Paul Marossy]

Here's an update. I found some time this evening to rewire my Firefly per my revised chassis layout, and it works just fine. Measured 6.9V on the heater supply and I've got the 12AU7 wired up right now. I must say that it is quite a pain in the rear to change these wires after the fact! Sorry once again.  :oops:

Anyhow, it sure does sound a lot different now. I thought something seemed a little funny with the way it sounded before, but I haven't played it very much yet, and I thought maybe it was just my speakers or something. It definitely sounds much more lively now and there is a major improvement in the level of hum. I only hear some hum when I crank the gain way up. I like it a lot better this way!

One interesting thing to note... the "sag switch" I installed that adds a 1K resistor in series with the B+ supply makes the amp sound different still. It almost makes it like having two amps in one, IMO. I am very happy with the tones I can get out of this little amp. Love my 2x8 speaker cab, sounds very nice.

I still would like to make this resonance control work, though. I'm not sure how to do it, though...