has this been done?/can it be done.........

[mcdes]

i was wondering, with all the talk about hum in amps, and how they normally have transformer at oppisite end of chassis to the input so as to stop interference.

my question?: if you have a small valve combo amp(epi valve special), and the transformer, though on the other side of the chassis, is still close to the audio circuits,..... do they already make something to put over transformer to sheild as much as possible? and would it even make a difference? or something along that idea?

cheers in advance.

:rolleyes:

[TimmyP]

If indeed the transformer is the problem, wrapping it in Mumetal should solve it. I think it more likely that adding a hum balance to the heater supply, or installing a DC heater supply, would be much easier and cheaper.

The proximity of the output transformer can also affect the circuit. The sonic result may be good or bad.

[PRNDL]

Hum is usually caused by other things: ground loops and improper grounding, electrolytics (not enough filtering), mismatched tubes, heaters, etc.

[VaughnC]

If your amp hums with no guitar plugged into it, there's something wrong with the amp or it's a bad design.

However, if your amp hum occurs only when you plug into it, then the hum is coming from external sources (lights, house wiring, appliances, etc.) and most likely getting into your guitars wiring and pickups.

[mcdes]

its an epiphone valve special which sells for about $299 usdollars, of course its a bad design, its cheap. ha.

its an all valve (3) practice amp that i just thought i might tinker with, see if there was a simple solution to fix hum, hum comes from amp itself, when nothing is plugged in.

[Trout]

If your amp hums with no guitar plugged into it, there's something wrong with the amp or it's a bad design.

However, if your amp hum occurs only when you plug into it, then the hum is coming from external sources (lights, house wiring, appliances, etc.) and most likely getting into your guitars wiring and pickups.

Thats is not entirely true in some cases. I have seen several model amplifiers that have apparent hum until you dig into them a bit. Some power transformers actually " Vibrate" physically during operation which is often confused with hum. I have seen this occur with several Vintage Stancor, Triad, Thordarson models as well as a few new production Hammond,Lenco, and MPS units.

The level of Hum/Vibration during operation varies from brand to brand, but either way, it resonates on the chassis and can very often be confused with power supply circuit hum.

Trout