If I wanted to play with mod'ing the build of my Allen Old Flame for clean tone, where would you recommend I start? Would any of O'Connor's books give me a clue, or are there other sources? The amp has 6L6GCs with a GZ34 rectifier tube.
Brandon - do you do this work? In other FX loop post I started, you said this:
"The Old Flame is basically an AB763 with a PPI master, it already has that tone-leach 3M3 fender reverb mixer resistor figured into the equation, what could a built in loop hurt?"
Is there something I could do there?
Here's the schematic and chassis pic (the chassic pic has some wiring errors that I fixed after snapping the photo):
A few ideas in no particular order to maximize clean tone...
-- remove the bypass cap from V1B
-- replace V4 with a 12AT7
-- change the dropping resistor values in the PS to 1K and 4.7K like a Twin
-- remove the MV circuit, or always keep it full on
-- use a solid-state rectifier
"We put a little quality in everything we build..."
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oldhousescott wrote:A few ideas in no particular order to maximize clean tone...
-- remove the bypass cap from V1B
-- replace V4 with a 12AT7
-- change the dropping resistor values in the PS to 1K and 4.7K like a Twin
-- remove the MV circuit, or always keep it full on
-- use a solid-state rectifier
Thanks for that. I did end up ordering some O'Connor books from Elderly to understand this stuff better.
I'm not a Twin fan - like the Super Reverb and Vibrolux better - so I'm guessing that I shouldn't tamper with the PS resistors? I've listened to some Cowtipper clips compared to some BFs, and like the girth of the CTs, so that's what I'm looking for (that, and winter projects).
Re the rectifier, I think I like the sag that comes out of this amp, though I can't tell you it's from the rectifier.
oldhousescott wrote:A few ideas in no particular order to maximize clean tone...
-- remove the MV circuit, or always keep it full on
I'll also point out that keeping the MV full-on introduces too much hiss, so that's not an option. Perhaps that points to some bad build on my part, or it's unavoidable.
oldhousescott wrote:A few ideas in no particular order to maximize clean tone...
-- remove the MV circuit, or always keep it full on
I'll also point out that keeping the MV full-on introduces too much hiss, so that's not an option. Perhaps that points to some bad build on my part, or it's unavoidable.
Maxing the MV should not cause hiss. Even with a 12ax7 PI. It's the "same" as not having a MV. Especially if the regular volume and reverb are down. Could be a bad tube or component causing hiss. For clean, you want no MV or keep it on 10. Or 11 for extra clean.
