Wow.  That's a lot to take in.  I definitely see what you're talking about concerning pots.  I've used everything from Rat Shack pots with the long shaft that needs to be cut down to salvaged pots from old stereos and vintage electronics.  With the PCB aspect, I meant that the program didn't seem to allow for value editing, as in putting (for example) 1K on a resistor.  I think that some of the CAD programs take a bit more time and effort in order to understand how to use them.

Precision is absolutely key to placement.  In regards to soldering pots to the board, I prefer using short wires (solid 22 gauge) to connect.  I leave the board for the components.  Your build is absolutely amp style rather than the sometimes cramped stomp box.  I'm all about the sexy build.  It keeps wires from crossing over each other - power for example - while also giving it an amazingly professional look that most audiophiles are looking for.  It'll take me some time in order to understand how to read the schematics but, I'm definitely looking forward to the challenge.

Hey Phatt,

Do you happen to have a copy of the PCB layout?  I'm trying to convert it through PCB layout but, some of the symbols are different (phone jacks and such) while others, such as component values, are a bit difficult to locate.

Thanks

I like the PhAbbTone idea.  I'm assuming this sits in its own enclosure as a pedal of sorts, right?  I have to try and convert it to stripboard.

The P1 point.  Is that both input and output?  I'm imagining that I can use a few preamp builds I've seen around the net to insert into the schematic.  My only issue is the connecting points on the board itself.  I admit that I'm sort of intermediate with electronics - I build stomp boxes and have done a few mods to amps before. 

Ha!  Thanks.  I've already removed the reverb circuit.  It's got a couple of BC169s that I can salvage for other projects.  I don't have the tank anyway. 

Thanks, Roly.

I'm looking to add a midrange control and deepen the bass, possibly with a different cap on the bass pot?  It doesn't have a mid control.  I've seen tone stacks for Fender and Marshall amps but, they lacked the use of any transistors - this one has BC169s in it. 

Hi,

I have a Univox U50 PA head that has a 6L6 power section with a 12AX7 phase inverter.  It's a hybrid amp from the 70's.  I'm trying to see if I can alter the tone section in order to add a tone stack.  It has three knobs (four channels) - Volume, Treble, and Bass.  I'm also trying to see if I can add a tube preamp to it, taking out the solid state section.  Here's the schematic with markings - the part on the left is the tone section: