This is my first McIntosh post, I am a relatively new to vintage audio, and know nothing about repairs. I am trying to be a safe beginner.
My dumpster rescued MA6100 was DOA, so I sent it to Terry Dewick. He rebuilt the left channel with new output transistors/ audio path upgrade, etc. The unit quickly developed volume control problems. Fader lube fixed that for awhile. I know it is not a good match, but I paired it with newly acquired AR9s. The second time I turned on, it came on at full volume!
I bought a volume control from an ebay vendor, installed w/o issue, and it works, however, when turning it on, the left channel comes on first (no sound from the right) until I turn the volume up, then the right comes on but is not as loud as the left, and stays that way. Moving the balance to 2:15 fixes the imbalance.
I described the problem to the ebay seller. He replied as follows:
"HI Tony,
there could be several reasons.
1. When Terry serviced the
unit , he might have adjusted the signal strength for each speaker to even
out the original volume/balance control imbalances.
2. It also could be
caused by a new pot!
Here is few solutions.
1. You can even out the
balance by installing a resistor to lower the signal strength to the
strongest deck of the pot. Let's say the right speaker plays louder.
Install a resistor to the deck of the pot that is responsible for the right
speaker. (The value of the resistor will depend on the strength/imbalance
of the signal)
2. Send the control back for evaluation, if it is faulty, I
will replace it with another one."
I can't figure out how to adjust the signal strength, and there is not enough space to place a resistor in the small space around the volume control. I hope I can fix the problem without removing the new volume control.
I greatly appreciate any help!
Sorry about the long question. I hope I am posting in the right forum.
Thank you,
Tony
My dumpster rescued MA6100 was DOA, so I sent it to Terry Dewick. He rebuilt the left channel with new output transistors/ audio path upgrade, etc. The unit quickly developed volume control problems. Fader lube fixed that for awhile. I know it is not a good match, but I paired it with newly acquired AR9s. The second time I turned on, it came on at full volume!
I bought a volume control from an ebay vendor, installed w/o issue, and it works, however, when turning it on, the left channel comes on first (no sound from the right) until I turn the volume up, then the right comes on but is not as loud as the left, and stays that way. Moving the balance to 2:15 fixes the imbalance.
I described the problem to the ebay seller. He replied as follows:
"HI Tony,
there could be several reasons.
1. When Terry serviced the
unit , he might have adjusted the signal strength for each speaker to even
out the original volume/balance control imbalances.
2. It also could be
caused by a new pot!
Here is few solutions.
1. You can even out the
balance by installing a resistor to lower the signal strength to the
strongest deck of the pot. Let's say the right speaker plays louder.
Install a resistor to the deck of the pot that is responsible for the right
speaker. (The value of the resistor will depend on the strength/imbalance
of the signal)
2. Send the control back for evaluation, if it is faulty, I
will replace it with another one."
I can't figure out how to adjust the signal strength, and there is not enough space to place a resistor in the small space around the volume control. I hope I can fix the problem without removing the new volume control.
I greatly appreciate any help!
Sorry about the long question. I hope I am posting in the right forum.
Thank you,
Tony