The Amp Garage

Really nice work! Wanted to see if you had a good resource for building my first cabinet?

The ground connection wire actually was broken in the middle, going to the buss wire. Best I can figure it, it was just an intermittent connection and the high input would have quit working if I had had more than 5 minutes to play with the new amp since I got it built. Work always seems to get in th...

Had a broken ground connection from the preamp pot. Its working fine now

How much does the pre amp control affect the gain of the low input? In my clone build, it doesn't seem to do much

The kit came with Electro Harmonix branded power tube and JJ pre amp tubes. Honestly, after seeing the red plating and then looking at the socket, it's 100% my fault the tube fried. Something happened and the cable going to my dummy supply pulled out and the socket sparked. I've had nothing but good...

Your red plating might not be due to a bad tube, but due to a very strong good tube that happens to need a higher bias voltage then the other tube. This then really indicates that the tube which isn't red plating is weak. This would clearly show up on you scope when looking at the amps output wave ...

Yeah I purchased a matched set as soon as I made my last post. Figured, even if the problem was something else, a back up set wouldn't hurt. I was 99% sure I had a blown tube and, upon further investigation, I see some charring on the socket. I'm guessing that something happened to the test load cab...

That was with a signal. That tube, swapped into the V5 location, still red plated. I'm thinking bad tube.

How do I check the lead dress?

Here is a picture of V4

I've got the heater voltage issue worked out. Replaced the wire running from v3 to v2 and I'm getting consistent 6.4 volts. I am also getting signal through the amp now and controls are working as expected.

Issue I have now is that the V4 el34 appears to be overheating. Any thoughts on the issue?

So neither the on off main switch or the standby switch does not light up? Do you have a fuse in the fuse holder that’s on the primary side of the power transformer Also it’s real hard to tell from your photo, but I don’t think I see the needed jumper wire from one side of your ac on / off switch t...

My initial voltage readings on the heaters were off due to a fault MM. New MM up and running and the heater voltages are the following. With no tubes in v1 thru v5 all measure at 6.5 VAC With the tubes in v3 thru V5 all measure 6.8 VAC V1 and V2 heater pins are only reading 3.2 VAC. Shouldn't these ...

Hey,

Been following the forum for a while now but never posted. Building my first tube amp, a 2204 clone from mojotone. On first power up, no tubes, I get 120vac coming in as expected but no current on the heaters. Can anyone direct me where to start looking to troubleshoot?