Kenwood 500 Volume Pot Repair?

[sansevy]

Hi folks,

I recently purchased a Kenwood 500 off of ebay. The previous owner noted that the volume pot was not functioning properly and that his tech had given up on trying to repair it. I am assuming that I cannot source an original version or replace it, so I was wondering if anyone thinks it could be repaired.

An example picture of the intimidating volume/balance/loudness pot available here.

I haven't yet opened up the 500. I plan to do so next weekend. When I do, I wanted to get a sense of what to hear for/look for. Please let me know what you all think!

Thank you!
S

 

[restorer-john]

It is a four gang unit with a concentric balance pot as well. Two of the gangs have loudness taps at 50% and AFAIK, it is a printed resistor stepped pot too.

A nightmare to replace if it is wrecked, but it may be repairable if the previous tech hasn't completely destroyed it.

Otherwise, you'd need to find either a donor or modify the preamp/filter output stage to enable using a normal dual ganged pot and forego the concentric balance possibly too.

I'll have a look at the schematic.

 

[gort69]

I have a 500 that had a bad volume pot. Some nitwit drilled holes in each section I assume to get cleaner into it. In the process he wiped out one of the wafers. You can see a brief explanation of how I fixed it here, at post #1376. http://www.audiokarma.org/forums/in...d-owners-show-us-your-kenwoods.261271/page-69

Probably not the problem with yours, but here are a few photos showing how I took it apart. Lots of stuff to keep track of in there, so have a plan in place to keep the parts in the correct order, and make sure you have a way of getting the many wires back where they belong.

I'd recommend tracing the signal before removing the pot to find the bad section - and only disassemble it as far as needed to see if you can repair it. Depending on what is wrong with it, you might be able to find repair parts from a similar pot from a different unit. For some reason I want to say Pioneer SA-9100 could be a donor, but not sure.

It's intimidating, but I figured it was my only hope of saving the amp as parts units never seem to show up. Still going strong.

 

[sansevy]

I have a 500 that had a bad volume pot. Some nitwit drilled holes in each section I assume to get cleaner into it. In the process he wiped out one of the wafers. You can see a brief explanation of how I fixed it here, at post #1376. http://www.audiokarma.org/forums/in...d-owners-show-us-your-kenwoods.261271/page-69

Probably not the problem with yours, but here are a few photos showing how I took it apart. Lots of stuff to keep track of in there, so have a plan in place to keep the parts in the correct order, and make sure you have a way of getting the many wires back where they belong.

I'd recommend tracing the signal before removing the pot to find the bad section - and only disassemble it as far as needed to see if you can repair it. Depending on what is wrong with it, you might be able to find repair parts from a similar pot from a different unit. For some reason I want to say Pioneer SA-9100 could be a donor, but not sure.

It's intimidating, but I figured it was my only hope of saving the amp as parts units never seem to show up. Still going strong.


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Thank you, gort69. Those photos are super helpful. Helps me to know what I am taking on!