The Amp Garage

Mark wrote: ↑Thu Apr 10, 2025 2:01 am The output valves are 6GW8’s which are a 12AX7 and an EL-84 in one envelope.

No. Its a high-mu triode and a pentode in one envelope. Its like half of a 12AX7 and some other pentode that is dissimilar from an EL84.

I tried this by looking toward the AC30. I added the following RC filter b/w C5 and R9, but all it did was make the thumping brighter. https://live.staticflickr.com/65535/54309476815_a268a9eeb2_w.jpg You need to filter out lows even more if you want to get rid off the thumping. With those capacitor...

You need to filter out the LFO signal after V1B. Third or fourth order RC high pass filter is probably required to get rid off all the thumping when intensity is all the way up. I tried this by looking toward the AC30. I added the following RC filter b/w C5 and R9, but all it did was make the thump...

Hi All, I'm working on a build and having some tremolo issues. The details of the build are: AB165 Bassman preamp. Normal channel only. ECL84 push-pull power amp. I'm taking a lot of inspiration from the SoLow Watt project here, among others. I've built a few amps with this power section and find th...

Issue resolved! The problem was the board being too close to the jacks. I put some shielding tape on a piece of card stock, grounded via an alligator clip, and put it between the jacks and the board and that solved the distortion on the scope. I was able to pull it out and watch the distortion reapp...

Compare your V2 wiring to Fender's wiring. Your jumper between pins 1 and 6 goes directly across the socket while Fender's jumper loops around the socket, close to the chassis. Make your jumper look like Fender's jumper and see if some of your issues disappear. Good observation, and will definitely...

Compare your V2 wiring to Fender's wiring. Your jumper between pins 1 and 6 goes directly across the socket while Fender's jumper loops around the socket, close to the chassis. Make your jumper look like Fender's jumper and see if some of your issues disappear. Good observation, and will definitely...

I see that you've got the wires to your reverb control tucked in with your tone stack wires. Maybe try separating those? Good looking build! Thanks! Not my first rodeo, which is what makes this so puzzling. At this point i'm testing without V2-V4 even installed so its hard to believe the reverb con...

Pics! Board and control panel: https://live.staticflickr.com/65535/53971453615_51d3c56ac8_b.jpg https://live.staticflickr.com/65535/53971453610_d8cfcd1efe_b.jpg https://live.staticflickr.com/65535/53971453605_d310fb9b74_b.jpg Board and tube sockets (the jack between V2 and V3 is for footswitch): htt...

Okay, another dumb question...have you measured for continuity on the volume pot across the sweep? I mean, is it possible that the end of the track is dead when it gets turned all the way up? Have you tried rolling preamp tubes to see if maybe you've got a noisy one? Edit: You mentioned shielded gr...

Have you tried disconnecting the NFB? That'll tell you if your OT primaries are backwards. Yep, and no change. Here's what i've done since the original post.... Made sure that the Master Volume has no effect on anything. Ive tried it with the Master cranked and the problem is the same. WITH V2 INSE...

Hi All, I'm building an AA164 Princeton Reverb and having some issues with noise/shutoff at elevated volumes. I'm building to Fender's schematic and using my own layout, modifed from Fender's. Everything works and sounds good at lower volumes, it just goes south as you turn up. Here's what I have go...

Does the amp itself work or are you oing to gut the chassis and build something else inside?

Hi All, Trying to help out a friend in the UK get a panel made for an amp. Nothing fancy, probably just black and white like a Hiwatt. Here in the states I use a service where I send them an Illustrator file and they etch and mail it to me. Anyone have a recommendation of something like that in the ...

The 10K pot that Fender used is capable of providing proper bias range for Deluxe Reverb up to Twin Reverb simply by slightly changing the ACV input and the tail resistor on the pot. And the Fender pot can be adjusted internally or externally. Sounds like you already have the ultimate pot. The Dyna...