Tube Amp Archive

Thanks for the replies. I have uncovered the power cord and connected the ground to a power transformer mounting bolt with a strong crimped and soldered lug. The heater wiring was slightly neater before I started yanking it around to wire up the other pins of the power tubes. I do plan to keep the h...

I have just started building a blackface Twin Reverb and after having wired up the mains, I decided to move the bias pot to the empty ground switch hole on the back because I've already got bias test points back there. Anyway, this has cut down on the amount of space between the heater wiring and ma...

The amp played fine prior to the rewiring. I managed to track the problem back to the negative feedback circuit. Ive just unplugged the negative feedback lead coming off the speaker jacks. I assume its a bad electrolytic cap so Im going to leave it unplugged until I get some new caps ordered. I cant...

I bought a Peavey Deuce VT recently that had a bad tube socket so I replaced it. In doing so I had to remove the tube sockets PCB and hand wire the sockets up. Before I did anything, I tested the amp with two power tubes in, instead of the four, and it sounded fine with no issues. Now that I've got ...

The heaters are wired with 6.3AC in parallel with one side to ground. The way I interpreted that excerpt was that for heater current, since the resistance is so minimal you have to measure the diameter of the wire used in the winding itself, or to measure for a significant voltage drop under the loa...

So it seems like I need to wire up the heater winding to four 6l6s and 6 12ax7s then measure for a voltage drop to see if the transformer can handle the load. If not, a supplementary 6.3v transformer will be used for the preamp's heaters. How would I adapt the power supply to compensate for the 370 ...

Should I be more concerned about the heater supply current, or the high voltage winding current? One side of the heater winding is grounded and there are 4 6l6s.

Thanks, I'll have to do a search for it. The first thing when that I thought of when I got into this amp was the Twin Reverb. Seems like that was what Peavey was going for with this amp. The chassis even shares the same dimensions.

Picked up a Peavey Deuce VT for $80 over the weekend and I have been thinking about building it into a Twin Reverb. Currently the power transformer is powering 4 6l6GC's and I'd like to know if there was a way to measure the current rating. I've also heard of using separate power transformers to pow...

I don't think this would have any effect on the voltage being high but I did use 22uf 450s in place of the 100uf 450s. Would not having the load of the 12ax7 or the resistor and zener that went along with it cause the B+ to be higher?

I wish I knew these things but there are no markings on the PT or OT. Assuming that they haven't been damaged somehow they should work fine as they came stock in this amp.

I caught that error in the schematic along with a few other obvious ones like the half of the low voltage rectifier being grounded and the polarity of caps in the bias supply. The tubes should be fine as I was always very quick to flip off the standby switch. They weren't on long enough to red plate.

Double post

Sorry about that. Messing with it some more, I found that after replacing the 47v zener diode in the bais supply, the bias voltage went from about negative 40v to 50v. Seems to have gotten the plate down to about 550v but thats still 100v higher than the schematic shows. [img:823:949]http://i51.tiny...

Do you mean the part of the amp, or is the image not showing up at all? I built from the effects return and on. It starts on the far left of the schematic.