I could use a bit of forum wisdom.
I was using my Tweed Bassman Ltd 59 tonight and it started to emit a burning smell, actually the smell got that strong I had to turn the amp off and leave it alone.
Now it has been a while since I’ve beem able to use the amp Where the volume was on 7 but I shouldn’t have thought that was problematic?
Are these Bassman amps prone to this?
Full disclosure - whoever owned it before me has had some sort of master volume fitted to the back of it. I haven’t used it as I think it sounds rubbish.
The amp does hum more than my other amps which I am guessing would indicate some sort of problem?
Any words of of wisdom from the usual suspects
@ICBM @Modulus_Amps @Van_Hayden @RiftAmps
Comments
it smelt like a pending electrical fire though
This is the result of their decision to use a filament fuse and not an HT fuse in a very expensive Custom Shop amp. Neither the filament nor the mains fuse had blown.
... but the ceramic valve socket got so hot that it burnt the chrome plating on the amp chassis white, as well as melting the wiring. Caused by a valve base burning that left enough carbon on the socket to make it arc.
Don't risk it.
"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 am booking it in with a tech. Can I ask you what would possibly cause a transformer to heat up to the point of burning up?
I am wondering if the person who put in the master volume mod did a hack job?
Interesting really as it would seem that these amps are almost made to fail or work not as well as they can deliberately?
Eqd Speaker Cranker clone
Monte Allums TR-2 Plus mod kit
Trading feedback: http://www.thefretboard.co.uk/discussion/60602/
Karltone is good for any of the standard brands, including JJs.
The 230V issue is an EU standards thing by the way - one of the few things that’s genuinely wrong with an EU directive . Because the continental and UK/Ireland voltages were never really harmonised, just the tolerances widened to include both 220V and 240V, a '230V' amp in the UK runs too hot. For most equipment it makes no difference, but valve amps are unusual in that the voltages are stepped *up* not down inside, so the change is larger, and the excess power dissipation is related to the *square* of the voltage, so it can make quite a difference to valve life. There's also an issue in some amps with the low-voltage dropper resistors, which are under more stress at higher voltage.
Luckily almost all Fender amps are easy to swap from 230V to 240V just by moving two wires on push-connectors.
"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
*An Official Foo-Approved guitarist since Sept 2023.
*I have no idea why since no country has ever used such a voltage as far as I know, although it does have the advantage that you can deliberately set the late-70s high-HT-voltage models to it to reduce the stress on the valves. And where I work in central Glasgow has a measured voltage that is sometimes over 250V...
"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
Rift Amplification
Brackley, Northamptonshire
www.riftamps.co.uk
The transformers were also designed to run at 60 Hz mains; we have 50 Hz in the UK.
In many respects this is more relevant than the "exact" voltage, as the lower frequency of UK mains is more likely to run the mains transform into saturation, and hence run too hot.
Rob