Nice job on the schematic..!!
Kind of a funny way to number the Tone Stack and PI tubes.....
Did you ever try an AT7 in the PI.? Was that still too much gain for you.?
Thanks again for sharing you schem.
Well Done

10-4
You are welcome.

Here you go.......

http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/newamps/badcat_hotcat_30.pdf

It is probably just the taper of the pot. Pull the chassis, put a ohm meter on the wiper and one other lead, turn the pot and then compare it to an audio taper pot of the same value.
Best

Is it possible you have at least one blown speaker.?
Man.....you really need to plug into a different cab. Any cab. Do you have another one, or can you borrow a cab from a friend, or plug your head into a cab at a store.?
Best

Hey Kevin -
No I did not listen to the clips. They are so often useless for defining "tone". But if your amp is REALLY sounding bad......I will give them a listen now.
If I can help you with parts, send me a PM/email, and let me know. You guys have At Least one very good tube dealer....... http://thetubestore.com/
Best

75 Watt "green backs"......?
Are you talking about the GT-75 speakers.?
Not my favorite at all. But Marshall sold a billion of them, so who am I to complain. Though, I think those speakers tend to be very "bass heavy" and mid-scooped. Just My Opinion.

I do not really know. So now we are talking about an amp that sounds "bassy" To You. Another player with another guitar and another cab might think he was in Tone Heaven. If I had to guess I would say:
speaker(s)
tubes/bias
caps
I am not a guitar guy, but you could also play with your pickup heights.
But it seems like the other things I mentioned would be more likely culprits. Do you have some speakers you can try, along with different/new tubes.?
Your first cat by-pass cap is already pretty small. It may seem counter productive, but what if you raised that value.? Maybe a 2 or 4.7 mic.
Are you really hearing too much bass, mud, boominess.? Is it possible you are hearing, thin, dull weak, flat.? Hard for me to say. We all hear things differently and use different words to describe what our ears are hearing.
I don't know man.
Guess I would start with tubes and then speakers......
Good Luck

I don't know without going through your schem and comparing it to a stock 2204/2203.....
Are your tubes up to snuff. The only real way to tell is to change them out.
maybe compare your coupling caps to stock values. Cat by-pass caps also. You can get some pretty big increases in bass response from a relatively small increase in cap values.
Other than this, I do not have much for you.
Tubes
Bias
Cap values
Good Luck

Is this the schematic of your mods.?
I assume it is a JCM 800 of some derivation. How did it sound before you modded it.?

Yeah, take your pick,  look at the layout in my previous post.
I am not familiar with the 5V4, but I imagine the one tube cannot keep up with the demands of the PS.
Like in a Mesa Boogie....they have a Dual and Triple rectifier. 50 watts has generally been the rule of thumb for rectifier tubes. So in a 150 Watt Mesa, they have 3 rectifier tubes.

http://ceriatoneforum.com/index.php?topic=18.0
Are you talking about the amp that Ceriatone makes.?
It runs either One GZ34 or Two 5V4.
Best

Have you ever tried an AT7 in the PI of your head.?

Looking forward to some sound clips.
I believe i am familiar with that supplier in Germany.....Tube World or something like that. I think he sells Hammond exclusively. If all I had to choose from was Hammond, I would not be bothered at all.
Best

Hey Dave -
Sorry about the confisuion.....
Some guys have a long lead time getting parts, depending on where they live and who they order from. I was just offering to mail you a variety of 10 watts until your order arrived. But it sounds like Mouser (I love those guys) has already got you taken care of.
Best
Chip

Hey Dave....
Help on the forum is free, but my therapy rates are 300 dollars/hour. It is 9AM straight up right now. Shall I start with your obvious hate for your parents.....:-)
Anyway...maybe get some 10 watt resistors ordered for those new JJ's you have coming. BTW, the mA difference you see on your old tubes in not "huge"and may not even be enough to cause any kind of ghosting or any other problem. The benefit of "matched" tubes is still debated. A lot of guys prefer un-matched tubes. Whatever, I think for your purposes, a pair that is within 6 mA will be fine.
If you need something in a hurry, just let me know. I can see what I have and get them in the mail from USA CA 94585. You can send me some replacements when you get a chance. Just an offer. No big deal.
Best...
Chip