amio g-200

i am working on an ami g-200. my problem is i have a louder than normal hum while playing the record. amp does sound very good. i took the wire off to the extra speakers and the hum quit. sound isnt quite as good due to loss of speakers. my question would the problem be with one of those speakers, capacitors in the box its wired to or still in the amp itself. your thoughts please. norm

On May 14, 11:45*pm, wrote:

i am working on an ami g-200. my problem is i have a louder than normal hum while playing the record. amp does sound very good. i took the wire off to the extra speakers and the hum quit. sound isnt quite as good due to loss of speakers. my question would the problem be with one of those speakers, capacitors in the box its wired to or still in the amp itself. your thoughts please. *norm

Depends on what you mean by extra speakers:

A) If you have simply disconnected one of the machine's internal
speakers (woofer), then that will stop you hearing the hum, as that is
the only speaker in the machine capable of reproducing mains hum. The
hum will still be coming out of the amp though. It is filtered out of
the horn speaker on top by that metal box that has the filtering
components.

B) I presume you mean speakers outside the machine that you have
connected up ? Maybe they are overloading the amp, if too many, or
they or their wiring have problems (see below) and the filter caps are
weak and not sufficient to filter that higher load (but in that case
hum should increase with volume ?)


-That the extra speakers are somehow on the wrong terminal on the amp,
or there is a bad earth inside the amp on the speaker terminals and
the speaker leads act as an antenna for the hum ? Partially shorted
speaker leads (or even speaker voice coil) may do this, increase the
load on the amp but not the volume. (you have to turn the amp up
higher to get same volume level as before).

-Are the speakers connected to anything else outside the jukebox, like
a stereo system via a speaker switchbox, (switches a speaker or pair
of speakers between 2 different sources (amps) ) that only switches
one of the 2 speaker leads for example, and there is an earth being
made back to the other device that drives the speakers, or is the
other device somehow pushing its own hum back down the speaker leads
that is then coming out of the existing speaker in the juke ?
Unplugging the G's amp from the mains supply may determine this. If
it continues, its not the juke amp. (note, both devices may be ok on
their own, but form a hum circuit when one lead is joined.)

-Crazy but I have seen it done - a guy using a water pipe, house metal
framing or beam as an earth, and running a single wire to the other
side of the load - in this case a fencing wire that passed through
wooden posts.

-Are the speaker leads accidentally shorting (frayed) somehow to metal
such as water pipes, metal beams etc or the wire has been stapled, and
the staple has managed to pierce the insulation of the wire, and short
it to the above, or some other wiring in the building. Seen this
happen once with a telephone line and 70v speakers driven from a
jukebox in a bar.

On Monday, May 14, 2012 8:45:55 AM UTC-5, wrote:
i am working on an ami g-200. my problem is i have a louder than normal hum while playing the record. amp does sound very good. i took the wire off to the extra speakers and the hum quit. sound isnt quite as good due to loss of speakers. my question would the problem be with one of those speakers, capacitors in the box its wired to or still in the amp itself. your thoughts please. norm

thanks for the info. i am talking about the two smaller ones in the machine. i have ordered a rebuild kit for the amp as i thought it still might be the problem but ws hoping there might have been another solution. thanks norm