The Amp Garage

This Seismic cab is oversized, and I think they all are, at least in terms of depth. I am looking for the best product to trim the cutouts, for the chassis and depending on the cabinet, the back panels. The best thing I've seen so far is Edge Trim by Trimlok. The 1/2" with 1/2" leg length looks the ...

I have a 10" Jensen Alnico that I repaired with brown paper from a paper bag and Elmers, and it is my best sounding speaker.

These cabs are really quite reasonable and I am wondering if anyone has any experience modifying them to hang a tweed-style amp chassis from the top? I have some tube amp chassis' that I have cloned, so now I have the originals laying around with no cabinet, and of course I have extra speakers, so t...

I replaced the power filter caps in my 2 - 6L6 amp project this weekend, and I forgot to ground the Main filter for the plates and the filter for the screens - the preamp filters were grounded. I turned it on with a current limiter, and it seemed fine, so I gave it full power. I passed a signal thro...

I bought an old Sano 2x12" combo on eBay, and I am restoring it. It has to be 50 years old, but in great shape. The speakers are unusual - they have a trumpet shape. They sound good. Should I use them or replace them? If they blow, what are the chances they can be properly reconed? The trumpet shape...

I have a VVR2 that I am installing in a Fixed bias amp. I notice the two diodes on the parts list are both listed as 1w/12v zener diodes. Later on in the instructions that Dana e-mailed me, he mentions a 6v diode. Is one of the diodes supposed to be a 6v, or are they both 12v? Thank you to anyone wh...

Is this an Ampeg amp - kind of? It is a clone of a Sano Excelsior. I bought the Sano amp on eBAy, and was so impressed with the sound, and true point-to-point layout on terminal strips, that I built a clone that fits in the same cabinet, which is in great shape. My clone sounds even better !

I have a really nice sounding pair of NOS 7591A tubes, and recently I noticed that one of them had a rattle - something was rattling around inside the tube. I was really bummed, and thought the tube was history, but it still sounded good. I was eventually able to bring the little object into view wi...

OK, I've moved the MV to one stage earlier (before the first 12AU7) and so the whole of the NFB loop is now fed by the VVR. Sounds better already! In this case, is the MV referenced to ground?

Thanks Dog ! I made the changes to the power supply that you recommended and the anode voltages are now mostly in line (thanks for the Ohms law refresher) :oops: I have noticed some other challenges with implementing power scaling of only the power tubes and PI with this amp. The negative feedback i...

Here is my schematic - thank you

Yes, I do see that. I thought I would try regulating the PI and power tubes because it was convenient for this amp in regard to implementing the master volume and locating that POT on the panel, and because I wanted to try out the idea as described in Merlin Blencowe's Power Supplies book. I will tr...

I am using a VVR2 to power scale my amp's push-pull 7591A power section and cathodyne phase inverter which is a 12AU-7 triode. Power to the rest of the amp's preamp circuit is unregulated. I implemented a master volume just before the cathodyne. I have found that even with a very large dropping resi...

Thanks for your response - found the 18 watt reverb schematic - interesting ! I should have said that mine is capacitor-coupled to the input of the reverb tank Ampeg-style, and not transformer coupled. Not sure if this makes a difference, circuit-wise.

I have an old Sano/Excelsior amp with a 7199 reverb driver. It originally had the pentode section wired as a triode, with a 10K anode resistor and a 200 ohm cathode resistor, unbypassed. It sounded OK. I rewired it as a pentode, added a dedicated power filter section, and a 56K dropping resistor and...