Tube Amp Archive

I'm new to this circuit so still feeling it out. Since the amp already had some switches installed, pull switches on pots etc, I have both the bright cap and peaker on switches right now. The bright cap dominates especially at the low volume settings I'm running. Since I am looking to run clean or s...

Well I turned the preamp into the 1987 circuit. What a beast! I kept my preamp master. Not sure how you can run these without it. Loud and clean but will break up when pushed for sure. So if anyone has proven mods for taming down the bright channel I want to hear them. Serious ice pick. That .005uf ...

I got this amp on the bench yesterday. Tried fattening it up with larger bypass cap 1st stage from .68 to 2.2uf. Also soldered a 1M across the volume pot to drop overall gain. And warmed up bias on 1st 2 stages. Still too much gain. So next step is convert to the 1987 circuit. Do most of you running...

I'll check it out. Most likely will be trying a different circuit, but I like reading this stuff. When I built the amp I was doing a lot of reading, particularly Tone Lizards JCM800 mods and info. That's an old version of the London Power scaling. From the dates on my drawings this amp was built in ...

Hey guys I've been working so kind of got pulled away from amp obsession. But I'm back. I think you're right on the cold clipper not cleaning up as well as a typical cathode bias values. I ran my amp with a switch for awhile that gave me the standard 10K and something else. I tried a lot of values b...

Thanks for the suggestions guys. The output tap labeled 8 ohm on my schematic is the original 4 ohm tap. Really my only beef with the OT is the presence not working well. It works but it's far more subtle than most amps I have played that have presence controls. I figure I'm never going to make this...

Hey folks, my 1st post on this forum. I have built 3 amps, with the last about 10 years ago. 2 SE amps based on AX84 designs, and an old Carvin X100B chassis modded to a 50 watt JCM800 based design. I lost a good job and for awhile I was doing tube amp work for side money. That was great because I w...