My Vox AC15 recently started producing loud sudden staccato buzzing intermittently during use, including when I’m playing and not touching the amp.
Despite replacing power and preamp tubes, the issue hasn't gone away.
I now wonder if it might be the standby switch that's faulty:
- There's a recent similar noisy buzz when turning standby on, different from the usual pop.
- Holding the switch midway during power transitions reproduces the annoying buzz.
- Applying slight pressure to the switch's plastic housing generates similar noises.
A couple of questions for you amp repair experts:
- Could a failing standby switch be responsible for the buzzing issue described above in the first sentence?
- Where can I find a suitable replacement switch? A photo is provided below. The sticker says Chily 6021 16(6)A 250V T125 and 16A 125VAC 10A 277VAC - but I can't seem to find that exact switch available online in the UK.
Comments
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Many thanks! I’ve spotted this US website lists this switch as a replacement: Vox® AC15C1 Power & Standby Switch Upgrade – British Audio
I’ve found it here, available in the UK: 641H/2K | APEM Toggle Switch, Panel Mount, On-Off, DPDT, Solder Lug Terminal, 250V ac | RS (rs-online.com)
Would that switch work as a replacement? Seems quite expensive, mind you!
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Is the other side of the switch failing an inevitability? If so, I’ll go ahead and replace now rather than wait for it to happen at a more inopportune moment. But if not, I might just leave it as is and play on.
Ideally, I would connect both sides of the switch in parallel and fit a suppression cap across it - even with one side damaged, that would almost guarantee it doesn’t fail.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I wonder if it’s better just not to use standby at all, and just leave that switch ‘always on’, using the power switch alone to turn the amp on or off? There seem to be quite a few people online advocating that approach. But then, there are also people who say that it *is* important to use standby on an amp with a solid state rectifier, which would include my AC15C1…..
My trading feedback: https://www.thefretboard.co.uk/discussion/210335/yorkie
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein