2. amps-preamps
  3. 1230236104

Integrated changes input selection by itself

Hello. My MF A3.5 has started changing it's input selection to Tuner ALL BY ITSELF. It does this intermittently. I have only two inputs connected, CD and Aux1. There is no other source for the amp to play, yet it switches to Tuner every once in a while. It plays normally, and then jumps to the Tuner input. I then select the Aux1 or CD input with no effect other than I missed a few bars of Jazz. Everything else seems to be normal.

I've had the amp for several years now, and purchased it as a demo from an Audiogon member. This behavior of self-selecting to the Tuner input is a very recent phenomenon.

Here's my system: http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1187457873&view. I've traded up to the Quintet for power filtering and upgraded the speaker wires to Kimber 8PR, all last year.

I could not find any posts with this issue so I'm asking this community for comments and suggestions. Thanks.
128x128markemark
plato
1,543 posts
 
An electronics designer told me that sometimes AC filters can boost the line voltage a little bit to make them sound better... but if your line voltage is already on the high side (mine is) the extra boost can cause op-amps to bug-out.

Instead of plugging your integrated amp into the AC filter, try plugging it directly into the wall and see if that eliminates the auto-switching. If not, then it might be time to send it in for service as Tvad mentioned.
markemark's avatar
markemark OP
12 posts
 
Thanks for the suggestions. Since re-cycling power, the unit has not changed input selections. I still have the IR port covered too but I plan to remove that if I the good behavior continues.
markemark's avatar
markemark OP
12 posts
 
Interesting development. The system changed input selections after I removed the post-it note covering the IR port. It does this after some time just playing. Seems like something is triggering it. I'm going to try removing the batteries from the remote and removing the post-it note from the IR port.

Must find gremlin.
Post removed 
badcap
15 posts
 
If you have an fluorescent light near the sensor it can cause the problem.
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