hi, not sure where to post this. sorry. pickups hum / buzz

[witzendoz]

I had a problem back in the 1980's when I moved into a house opposite a phone exchange, it had rectifiers that was in fact transmitting RF back along the power cables into my place, we built the first studio there and a lot of guitar rigs picked up the RF.

1st thing we did was to improve the building earthing, this reduced the problem on a lot of the rigs, then I made up a light cable with a clip on one end and a small metal plate on the other, we would put the plate inside the guitar players paints (no not there) where his belt was, touching his skin, and clip onto the shield on the jack plug, this way the noise did not increase when he lifted his hands off the strings.

Final solution was to buy a mains isolation transformer volts in = volts out, but no internal connection, and plug the guitar amp into this, all quiet. Luck don't have that problem anymore as we have moved a few times, checking power before we make an offer on the building.

Alan.

 

[Jay C]

I had a problem back in the 1980's when I moved into a house opposite a phone exchange, it had rectifiers that was in fact transmitting RF back along the power cables into my place, we built the first studio there and a lot of guitar rigs picked up the RF.

1st thing we did was to improve the building earthing, this reduced the problem on a lot of the rigs, then I made up a light cable with a clip on one end and a small metal plate on the other, we would put the plate inside the guitar players paints (no not there) where his belt was, touching his skin, and clip onto the shield on the jack plug, this way the noise did not increase when he lifted his hands off the strings.

Final solution was to buy a mains isolation transformer volts in = volts out, but no internal connection, and plug the guitar amp into this, all quiet. Luck don't have that problem anymore as we have moved a few times, checking power before we make an offer on the building.

Alan.

damn good idea, i'm moving into a new place in june so i should get that looked at. the good thing is that the guy who's selling it to me plays and i would just hope he wouldn't put up with it.

thanks

 

[Ainaudio]

This noise is coming from 2 sources - pickups and unshielded electronics parts.
Pickup's noise part depends from pickup orientation and location (try it close to amplifier's power transformer), unshielded electronics part of noise is relatively stable (maybe little bit only changing from location to some noise sources).
If you have single coil pickups - it is impossible to remove 50-60 Hz hum and EMI/RFI interference fully.
Even perfect full shielding will only reduce single coil pickup noise some 4 times (it is not so bad - you must shield your guitar anyway).
The same time full shielding removes all noise from electronics part.
Pickup noise solution is to use "noiseless" pickups or "dummy coils", but both case it will damage sound.
There is only one perfect exception: Kinman patented pickups for Strat, Tele, P90.
They sound great (even better as the best vintage single coils), and are very quiet - more as std humbuckers/stackers.
* Many (if not most) professional Strat/Tele/P90 players are using only them, but with "no brand" covers - you know why
So full solution is: Kinman pickups + full & right grounded shielding + quality first cable.

 

[ecc83]

"Final solution was to buy a mains isolation transformer volts in = volts out, but no internal connection, and plug the guitar amp into this, all quiet. Luck don't have that problem anymore as we have moved a few times, checking power before we make an offer on the building."

Hi Allan.
I would guess that the transformer worked because it had an interwinding shield that blocked the incoming RF? This result might have been acheivable using RF mains filters but you would probably have had to "roll your own".

But talk of mains "isolating transformers" alway causes me a shudder! They are often used to provide "balanced" mains and in such a case lay a death trap for an unwary repair tech!

I would urge anyone contemplating any kind of work on the mains supply side to employ a qualified electrician well versed in studio electrics.
Also run any proposed measures past the guys at Sound On Sound | Recording Techniques | Audio Technology | Music Production | Computer Music | Video Media forum. There are several bods there with vast, world wide electrical safety knowledge.

Dave.