The Amp Garage

Hey everyone, Im just starting a new build which is going to be a supro model 24. Ive got most of the board work done, a few more things to solder. Ive got a couple resistors on the back as i thought it would make the build neater. Ill be building it with a watts chassis/board. More parts coming soo...

Im in the process of building a supro model 24, using ken watts' chassis and board set. Ive got solo caps, f&t filters, pro resistors and some other parts coming, i think it should sound sweet. Anyway, I'm going to be mounting this amp in a 2x12 tweed twin cab, with a celestion blue and a g12h30. Im...

Bias mod trems on output tubes can be fussy about how the tubes are biased in the first place. If the bias is set hot, the trem will typically have less effect. Since it was working and then didn't, I'd guess the 6V6s have settled in and are drawing too much current. Try adjusting the bias circuit ...

Sorry for the long wait, i hope someone can still help. I got around to taking voltages tonight on the trem triode. Pin 1 of v4 is now at 240 volts and pin 3 is at 2 volts. This is much different than it previously was. The cathode cap seems to be okay but i can swap it out to be sure. Any thoughts?

Not to bust your Ass, but this is a classic example of why when you build a amp , or work / repair a amp and it's working real nice you take 30 minutes and note down all the voltages for future reference!! This can save you endless hours of trouble shooting! On the Cathode of your tube do you have ...

Not to bust your Ass, but this is a classic example of why when you build a amp , or work / repair a amp and it's working real nice you take 30 minutes and note down all the voltages for future reference!! This can save you endless hours of trouble shooting! On the Cathode of your tube do you have ...

Hi all, Im having some issues with my Princeton reverb's trem. It was working just fine, and then all of a sudden it went really weak. I tried swapping the tube from an rca 12ax7 to a known good tung sol and it doesnt work at all with that tube. When i shut down the amp with the rca in, the trem wil...

but there is no r14 equivalent in his schematic. Is it something that should be added? Not necessarily. But your presence pot would be about 5K if your circuit doesn't use that 4.7K resistor. And it would be wired a bit differently. Look at some early Marshall schematics to see what I'm talking abo...

Looking at this schematic: http://ampgarage.com/forum/download/file.php?id=6861 and your pictures I can't seem to find R14 (from the linked schematic above). R14 should take the DC bias current of the PI to ground. If it is not there and all of the PI current is flowing through your presence pot (w...

Its definitely 65, sometimes even jumps above 70. When i touch the meter leads to it it even arcs to the probe sometimes. Ill check my work around that area and see where ive gone wrong.

V5 and V6 pin 4 voltage is way too low. Should be almost the same as pin 3. You have used a 15K resistor where a 1K resistor should be used for B+ screen node. Put a 1K on the board and see if that doesn't improve things. See pic... Okay, definitely will swap that out, i cant believe i missed it! A...

V5 and V6 pin 4 voltage is way too low. Should be almost the same as pin 3. You have used a 15K resistor where a 1K resistor should be used for B+ screen node. Put a 1K on the board and see if that doesn't improve things. See pic... Okay, definitely will swap that out, i cant believe i missed it! A...

Voltage chart

Hi everyone, A while back i built a princeton reverb off a mojo fiberboard. The clean is gorgeous, but the drive is absolutely horrendous. When its on the edge of breakup theres just a small amount of really sweet sounding overdrive, but as i turn the amp up it just gets buzzy and blatty and disgust...

Hi all, here are some updated pics of the amp. Hum is cured, just a lead dress issue, and the amp sounds great. Something im a but worried about is theres dc on the presence pot, about 64 volts. What is this from? Is it normal? As for the pt, it is large, but it was supplied to my by rj specifically...