avantbored
Active Member
Hi all,
I picked up a nice M65/C65 stack a month ago. The amp is being worked on, and I've been using the C65 very nicely with my M70.
Much of the scratchiness in the tone knobs, input switches, and volume/loudness pot has disappeared with use. But the volume knob's noise has not disappeared completely.
I flipped the thing over to loosen the cover, and found that some plastic around the screws that hold the cover to the chassis had cracked off. I remember when I had my C80, I also had intermittent scratchiness, and the plastic flanges were also cracked off there too.
I plugged the C65 back in and found that some of the noise (not all) disappears when I hold my hand on the preamp, and reappears when I manipulate the knob when I don't use my body as the ground.
The question: Are the plastic flanges the culprit, and how could I mitigate the problem?
PS. the M65 is being worked on now to remove the glue (the seller, who was selling on behalf of a client, did not quite trust me that the glue was a problem...) and offered to refund me the difference if the work order was more than a couple of hundred bucks. We coincidentally use the same person, so the work is trustworthy, but the tech also found some bunk transistors in the output stage (perhaps the result of a bad repair job in its life before me). He's still doing parts research, so maybe he's been poking around here!
I picked up a nice M65/C65 stack a month ago. The amp is being worked on, and I've been using the C65 very nicely with my M70.
Much of the scratchiness in the tone knobs, input switches, and volume/loudness pot has disappeared with use. But the volume knob's noise has not disappeared completely.
I flipped the thing over to loosen the cover, and found that some plastic around the screws that hold the cover to the chassis had cracked off. I remember when I had my C80, I also had intermittent scratchiness, and the plastic flanges were also cracked off there too.
I plugged the C65 back in and found that some of the noise (not all) disappears when I hold my hand on the preamp, and reappears when I manipulate the knob when I don't use my body as the ground.
The question: Are the plastic flanges the culprit, and how could I mitigate the problem?
PS. the M65 is being worked on now to remove the glue (the seller, who was selling on behalf of a client, did not quite trust me that the glue was a problem...) and offered to refund me the difference if the work order was more than a couple of hundred bucks. We coincidentally use the same person, so the work is trustworthy, but the tech also found some bunk transistors in the output stage (perhaps the result of a bad repair job in its life before me). He's still doing parts research, so maybe he's been poking around here!
