Stereo amp repairman in Ann Arbor?

[RTinDC]

Hi all, my first post! I gave my daughter my 1976 Kenwood KA-3500 as a present a couple years ago when she was in college. (She loves vinyl, esp. 70's rock/pop.) The amp is having a sound problem (it's not the speakers, we ruled that out) on one side. Garbled sounding apparently. It started about three weeks after she got a second pair of inexpensive AIWA speakers and hooked them up to the "B speakers" connection, often running both sets of speakers at the same time. I noticed they were 6 ohm when I was up there recently - the other speakers are 8 ohm Advents. Wondering if she may have cooked something due to the mismatch.

Can anyone recommend a trustworthy and competent repairman in Ann Arbor, MI? Thanks,

Roger

[The Dude]

That amp is rated for a 4 ohm load. Your total load with both sets of speakers would have been about 3.4 ohms. That amp should be able to deal with an extra half ohm no problem. I don't know any techs in that area, but someone here may chime in with that info.

[RTinDC]

Update - found a guy via CL who seems like he's competent. Bench charge is $65, pretty standard.

[RTinDC]

That amp is rated for a 4 ohm load. Your total load with both sets of speakers would have been about 3.4 ohms. That amp should be able to deal with an extra half ohm no problem.

Thanks for that confirmation on the ohms thing. I'm a guitarist and no stranger to speakers and impedence ratings, but wasn't so sure about an old stereo amp vs. a guitar rig.

[The Dude]

Just an FYI: A common problem with those older units is that switches and pots get dirty. If you're at all competent, try cleaning and lubing pots and switches with Deoxit or similar. If that's out of your wheelhouse, just work all the switches back and forth, in and out, and rotate alll the pots thoroughly a few times while the unit is off. Often times that will fix the problem.

[RTinDC]

Just an FYI: A common problem with those older units is that switches and pots get dirty. If you're at all competent, try cleaning and lubing pots and switches with Deoxit or similar. If that's out of your wheelhouse, just work all the switches back and forth, in and out, and rotate alll the pots thoroughly while the unit is off. Often times that will fix the problem.

Good suggestion, I have had dirty pots/switches on that Kenwood in the past. Since the trouble is on one side, and only with the "A" speaker block, seems less likely it's a switch/pot issue this time, but will talk to her about giving all the knobs & switches a good turning while it's off.

You know, I didn't check with her to see if she reversed the RCA inputs from the turntable to rule that out as a source. Need to do that.

[g1]

Since the trouble is on one side, and only with the "A" speaker block, seems less likely it's a switch/pot issue this time,

A lot of the pots and switches are dual units, controlling both left and right. And both sides of switch or pot do not have to go bad at the same time. So it's still likely, and if you are saying the 'B' speakers don't have the issue, the 'A' speaker switch is a likely suspect.

[RTinDC]

A lot of the pots and switches are dual units, controlling both left and right. And both sides of switch or pot do not have to go bad at the same time. So it's still likely, and if you are saying the 'B' speakers don't have the issue, the 'A' speaker switch is a likely suspect.

Good to know, I will pass it along. If we're lucky, she won't even have to take it in for repair (fingers crossed).

[RTinDC]

Quick update, it does indeed appear to be dirty pots, volume in particular. Going to watch some YouTube videos on cleaning (w/ Deoxit, based on comments here) the various pots, switches and buttons, then dive in. Thank you all for your help, you made a difference!

[Tom Phillips]

...second pair of inexpensive AIWA speakers ... I noticed they were 6 ohm when I was up there recently,

A 6 Ohm impedance rating would be really unusual. I'm wondering if you determined that by measuring the DC resistance of the speakers. If so, then I would say that the speakers are actually 8 Ohm impedance.
Just a thought since I read that you are on the way to get everything working and are confident that the speakers did not cause the problem or do any damage.
Cheers,
Tom

[g1]

A 6 Ohm impedance rating would be really unusual.

It seems to be a thing with Hi-fi. I've seen home stereo cabs with 6 ohm ratings.

[Tom Phillips]

It seems to be a thing with Hi-fi. I've seen home stereo cabs with 6 ohm ratings.

Oh my! I googled it and read a bit. Another factoid that demonstrates that I'm living in the past. There are no 6 Ohm impedance speakers in my house.

[g1]

Another factoid that demonstrates that I'm living in the past.

We have 2 eight track machines in the house. One of them records. And I don't mean reel-to-reel either.