The Amp Garage

http://carlscustomamps.com/information-center
This one has a bunch of good basic info.

https://robrobinette.com/Amp_Stuff.htm
I'm really surprised I haven't seen this one yet. One of the most useful pages on tube amps I've come across.

The gassed out tube could have happened for any number of reasons. But, the standard checklist for these is check for open Rg2s, and getting the bias right. So yank the output tube board out and replace any open Rg2s. While you're in there, do yourself and your client a favour and remove the spade ...

1). These amps have a specified way to set the bias as you may know. 2) the output stage has a 5 ohm 5 watt resistor on each tube that is there to blow out if a output tube shorts out yet still allow the amp to play on the other still functional tubes. 3) its critical that at least 2 of the 3 outpu...

I had this discussion with a friend of mine recently. Definitely good amp with crappy guitar. I'm working on an ampeg SVT right now. I'm primarily a guitar player but I keep a crappy beat up bottom of the line Squier bass just for testing amps. It's sounded bad/dull/muddy through every mediocre amp ...

I'm working on an Ampeg SVT for someone. I've only been working on amps for about 2 years now so I'm certainly no expert. I know enough to fix most problems, keep from electrocuting myself, and keep from causing further damage to the amp. Anyway, if some of you aren't familiar with these, there are ...

This Lafayette / Univox would not happen to be a combo tube model with 2 channels, reverb and 2-12" drivers in a horizontal cabinet would it, or is it the vertical 2-12 model ? Does it use 6973 output tubes and one preamp tube is a 7247? Is it SS recto? If so I one and have been trying to find the ...

I'm dropping it off for him today after work. Now I just need to finish his old Lafayette/Univox that I can't find any information on. Hopefully that won't be another post for help.

I replaced those non polar Electrolytics with film caps and she’s working like a champ now. Thanks so much for your input guys. I hope to return the favor some day. Wayyy louder than it was too.

The offset voltage is reading zero. The amp is pretty noisy and when I had a bass plugged in, with the volume up around 6, the speaker was vibrating at one point. Pretty sure that’s not normal. It was enough that you could see the grill cloth flapping a bit. Haven’t gotten it to reproduce that. When...

Thanks Steven! That's a boat load of awesome info. As far as whether they are germanium or silicon, I can't say, the schematic I have doesn't give any model numbers for the transistors. The two output transistors are PNP, that's about all I can say at the moment. I would love to find a parts list/se...

I do have a scope. Im just not sure it’s working properly. I was trying to use it to calibrate a rack compressor a couple weeks ago and wasn’t able to get a sine wave up on the screen. It was given to me a couple months ago and of course, like everything else I run into it’s a model that I can’t fin...

Since the initial post, I noticed that the JBL he installed is 8 ohm and the schematic says it should be 4 ohm. From what I remember, this isn't a big deal but will reduce the output. Could this be causing my weird fuzz and squeal above 9? Or is it likely unrelated?

Hi, I'm really hoping somebody can help me. I got a solid state Vox Kensington bass amp to repair from a friend of mine. I don't know much about these, info is kind of tough to find. I got a schematic for it, but can't seem to locate a service manual. The transformer secondaries were frayed and brok...