The Amp Garage

Now I have to figure out how to remove the cap and ground it to the correct place. Looks like I might just have to remove the turret board. Ugh. Dremel with a cutting wheel? Try to think out of the box. There's no set obligation to configure it the way it came to you -- I'm talking about the can ca...

Now I have to figure out how to remove the cap and ground it to the correct place. Looks like I might just have to remove the turret board. Ugh. Dremel with a cutting wheel? Try to think out of the box. There's no set obligation to configure it the way it came to you -- I'm talking about the can cap.

Picture of the subject cap? I am thinking, it may be more expedient and less expensive for the customer to clip the cap (if you can,) and mount it in a different location. For example, use a radial cap with a clamp mounted to one of the vertical sides of the chassis. Then, see if you can clip and re...

Excellent! Looks great. I don't see any provision to vent the heat. Do you see this as unnecessary?

If taking the bias supply from the B+ rail, I'd take it directly from the point where the red HT supply wire connects to the rectifier. I'd start with typical Marshall values You are shooting for bias range around -37V. If this were my build, I'd probably use the 125V supply you'll get from the Red/...

Red-Red no beep seems impossible. Bad contact with the meter leads? At least twice you reported 746V between the two Reds. (Remember wall voltage will vary, affecting secondary voltage. Not something of concern if you see readings that are up to about +/- 4% from a prior reading.) Also, seems quite ...

I think we've got some good information and some things that don't make sense to me. I have the sense that you aren't so familiar with power transformers, so I may be covering some basics that you already know. Please forgive me if I did not guess correctly. Also, due to the age of the transformer, ...

This is good progress. I think not all of the information is lined up the way we need it. The 5V, 6.3V and 12V windings appear to be settled. For the other leads there's a little more work to do. I'm reasonably certain you've told us that the two Red leads are the outer ends of the winding and the R...

Another thought...if there is a makerspace in your community and they have a CNC, you may be able to find someone there to help you.

Try searching FB Marketplace. You should be able to find someone who will do it for you. I just looked for "CNC" purposely keeping it simple because the FB algorithm isn't very good. Ignore the machines for sale and you'll find what you need. There will be just a few. Here's what I found in 30 secon...

As a follow-up question, I would like to see if I can increase the gain in one of the stages to get some increased distortion at higher volume settings. Are you aware that the owner of Ampeg was convinced that distortion was a very bad thing? The amps are designed for clean tone. You might consult ...

maxkracht wrote: ↑Thu Apr 17, 2025 4:35 pm

Phil_S wrote: ↑Wed Apr 16, 2025 9:29 pm Why not just rewire the socket that's already in the chassis? Something wrong with it?

I believe he means keeping the amp stock and using a 6eu7 to 12ax7 inline adapter

IMHO, that juice isn't worth the squeeze. Can't decide for others. Whatever floats his boat.

Why not just rewire the socket that's already in the chassis? Something wrong with it?

maxkracht wrote: ↑Tue Apr 15, 2025 1:15 am 12ax7 is a closer match. If you don't have or want to buy 6eu7s it's a good idea.

12AX7 is a perfect match for 6EU7. Same tube, different pin out. Some will think this is heretical mod. As Max says, it's a good idea.

Mark, please forgive me, as we are separated by a common language. I had to lookup "panel beater," as I didn't know the term. I'm sure your brother will take good care of the chassis.