The Amp Garage

What creates the ‘chime’ in a Vox AC15 amp? I’ve made a clone and I’m combing through a few issues like squealing at full volume (might be the variable voltage regulator), but also I don’t hear that distinctive chime I was hoping for.

That's a small chassis if it's like a original one to try and implement a power scaling circuit if that's what your referring to? You may need to work up a copper shield. Can you tell me a bit more about this please. I added a variable voltage regulator which lowers the b+. It is effective for lowe...

Remove one output tube at a time and play. Does the sound quality stay the same, or do you loose output totally when one of the two tubes are removed? Thank you for your reply. I have located half of the problem, unused (not anchored) captive nuts for the rattle and fizz and I think the squeal is t...

I made a Vox AC15 clone amp some years ago and finally got it into a cabinet last week and I have a nasty speaker distortion/rattle vibration. Would anyone recognise what the issue might be from this short clip. I’ve tried three good speakers and they all do the same so it must be the amp. The sound...

When I pull out these two plugs (one from the foot switch and one from reverb tank) the hum goes. It also goes when all are plugged in and the switch is turned off

Ah. I’ll try that tomorrow. Thank you.

No, hum goes when you disengage reverb

So, the task is to put back a hum pot that was removed. The amp sounds great except when the reverb is engaged and then it has a lot of hum. Any thoughts on what that might be. It’s been sitting unused for a good while.

This is fantastic. Thanks so much. I’ll get a picture of the back. I don’t have it in my bench yet, the guy wants me to put the hum pot back in. He says it was modded out of it some time ago.

Could someone help me identify the year and schematic number of this Silverface Twin. The owner wants a mod to be reversed.

Thanks

I made those mods on R35 (jumper) and R10 (66 because not got 62) and channel 1 seems even quieter. Will reverse it and compare

You can make it much better by swapping positions with R10 and R35. Even better if you replace R35 with a jumper wire and change R10 to 62K. Refer to linked schematic. Easier to see what's going on if you look at page 3. http://sluckeyamps.com/VAC15/Vox_AC15.pdf That is brilliant, thanks so much. I...

sluckey wrote: ↑Sat Mar 25, 2023 12:39 pm That's normal.

That's good to know. Thank you.

Hello, I made an AC15 chassis up about 10 years ago and never got around to completing it due to being overwhelmed with my teaching job, which I just retired from. I have dug out the AC15 and fired it up. It sounds great and need to get it in a cabinet. One thing that concerns me though is the outpu...

Phil, thanks a lot for your help, really appreciated. All sorted and have a record of new password; should know better as a former IT teacher.