does some know how to build a 60hz hum Eliminator which stops the 60 hz hum??

[sakis]

i am breathless .........

from all that ive read and all my field expirience the only one that stands a chance is gordy .....

presuming that everything is fine and correct with the construction and the power of the particular amplifier so it doesnt pick up any noises from plugs filtering ground connections and or ground loops ...
.........so lets suppose that everything is ok there is only 2 things to be done

A) once i had a problem quiet simular with a quitar ( well not really greek instrument looks like quitar and called laouto ) it prooved that someone in the past replaced the output jack but made a mistake in the polarity !!!!!!!!

B) and most of all in all my field expirience ( and that includes both terrible wiring and alot of dimmers ) there was no hum that resisted me after i installed a passive DI box !!!!! the particular one is called arctic and costs the astronomical figure of 8 euros !!!!!

finaly its not the instrument nor wiring nor dimmers that is sensitive to hum ..... mostly is the preamplifier input sensitive to pick up stuff like that .....

matching resistors ...... keep it too high or too low between instrument and preamplifier and then the cable becomes a wonderfull antenna that pick up anything ....

best regards sakis

[Nordic]

Unity gain buffers normaly deliver sliglty less than unity output...

[nobody special]

Originally posted by Nordic
Unity gain buffers normaly deliver sliglty less than unity output...

I guess if it's not an opamp that is definitely something to consider. With an opamp, the difference is negligible.
Guitar and instruments have one of the worst interfaces in general. My strat has a lot of the buzz mentioned above when in the "non-humbucker" positions (2 and 4, I think they're usually called). I've often wondered if it would help any to build a box that would provide phantom power to an on-instrument preamp (similar to a condenser microphone) that converts the signal to balanced low-impedance. The box that supplies the power could sit right on top of the amp and convert the signal back to single-ended and go into the amp at that point.
I guess the question I've always had was whether that would make a difference or not, as the pickup might be the problem and not the cabling. How about if the pickup was treated as a floating balanced signal with a differential input to the buffer/driver?
Sorry... not trying to threadjack... just thinking out loud. This is something I've thought about before.

[wakibaki]

Originally posted by Nordic
Unity gain buffers normaly deliver sliglty less than unity output...

You can't win.

You can't break even.

You can't get out of the game.

w

[sakis]

just for the heck of it id like to know

[huibert34]

If you have a problem with hum you should try a balanced line with a transformer and at the pre amp you can bring it back with a transformer to a asymetric line. if you stil have hum you can make a L C serial connection in your pre amp , for the L you can use a gyrator made with a opamp

[mace1337]

Originally Posted by GRollins

The way I do it on the basses I build is to wind a pickup coil, but use it without a magnet. Since it has no magnetic field of its own, it does not generate a signal from the strings, however it remains sensitive to all EMF fields in the area. I then run that signal into the main output out of phase, thus canceling the hum.
Or you could just use humbucking pickups...

Grey

That's actually pretty clever.

[racenjason]

16ls added tone control now amp has 60hz hum. I installed a ground jumper from the main transformer to the output transformer. hum now gone by 90%. I built the kit with no mods and sounds great.

[ingenieus]

Would a ground lift resistor help?

[jan.didden]

Originally Posted by sakis

i am breathless .........

from all that ive read and all my field expirience the only one that stands a chance is gordy .....[snip]

How can you say that if you don't even know the cause of the hum? As far as I know, Mr. Pass' method has been in use for, ohh, 80 years? by the tube crowd to null heater induced hum. Yes I know this is not a tube amp, but the principle is the same. Tried and proven, simple, easy, effective.

jan didden