will this work?

[Jason C]

Hey guys, I wanted to see if anybody here saw any problems with this circuit. I took the preamp section sans tremolo from an Ampeg Jet and put it on the output/power section of an Ampeg Mercury M-15. There is half a 6SL7 left over so I thought about using Baxandall tone controls but I'm not exactly sure as to how that's done. Also, If there are any ways to increase the headroom on this I would love to hear them. I want this to be an all clean jazz amp that I can use from small to large rooms. I'll be using a Cannabis Rex speaker. Thanks.
Jason

[loudthud]

The amount of actual clean headroom comes from a properly mathced output transformer, a stable power supply and an efficient speaker. Will you be using Ampeg Iron? A GZ34 rectifier tube will give slightly higher B+ and that will make a slight improvement. You could remove the 100uF cap on the first stage cathode and that will allow you to run the volume control higher but doesn't give you any usefull headroom unless you have a guitar with really hot pickups. Headroom is how loud the amp will get before it distorts, not how far you can turn the volume pot.

An actual Baxandall tone control circuit uses pots in a feedback loop. The James is the passive type usually seen on Ampeg amps like the B15. Many people (including me formerly) confuse the two. The James has a flat setting so it's not the same as what most people refer to as passive controls like the Fender tone stack. A gain stage is required after the controls to makeup for the 20dB insertion loss. I suggest you look for an Ampeg schematic with bass and treble controls and copy that.

[Jason C]

Thanks for the reply. I actually was going to use the transformers out of an old Wurlitzer organ amp that had a pair of 6L6's a 5U4G a trio of 6SQ7's and a trio of 6SN7GT's and a 6SL7GT. I figured that PT would not be taxed by what I propose. But as far as that schematic goes, does it look like everything will work? I guess I did mean the James tone stack. I looked at the B15 which has the controls I'm looking for but I can't quite figure out how to get it in there (I'm new to this as I'm sure you've noticed). Thanks again guys.

[Jason C]

Hey I meant to add that I'll have the other half of that 6SL7 for recovery if someone would be kind enough to explain how that's done.