Where to get Nashville 112 squeal repair?

[Jerry Touval]

Update 3/18: Nashville 112 back in full operation again. I brought it to an amp tech for diagnosis. He did a thorough cleaning which totally removed the squeal. Even the onboard reverb is working again with absolutely no hum. Total damage: $60. Happy camper here. Thanks to all for the helpful input!


My Nashville 112 started squealing today when I turned it on. After doing some tests suggested by ChatGPT, I got the recommendation below. Does anyone know a shop in Northern Virginia/DC/Maryland that can do this repair?

The Part That Commonly Causes the Squeal
The usual culprit is the dual op-amp in the preamp stage, most often a:
• TL072
• Sometimes NE5532 or RC4558
When one begins to fail it can oscillate at a very high frequency, which you hear as the high-pitched squeal. Because the Master/Post Gain amplifies it, the squeal disappears when you turn the master down—exactly the symptom you described.

Typical Fix Steps
(Only if you're comfortable opening the amp.)
1. Unplug the amp.
2. Remove the four chassis screws on top.
3. Slide the chassis out.
4. Look for small 8-pin chips in sockets on the preamp board.
5. Gently remove the TL072 with a small flat screwdriver.
6. Insert a new TL072 in the same orientation (notch direction matters).
Cost:
• TL072 chip: $1–$3
Many players replace two or three of the op-amps at once since they’re cheap.

[Ron Pruter]

When some of my pots on my 112 petered out it was pretty noisy. I got looks like" hey! get that thing out of here". Get alone, wear ear plugs and shake some pots around to see if you can isolate which pot/pots it is. RP

[Dave Grafe]

Before changing out IC's carefully clean and re-seat all MOLEX connectors in the amp, they are notorious for causing trouble.

If still no joy it's time to swap out IC's. If you follow the instructions above you can do this easily yourself. Get TL072 for this application, and maybe replace them all while you have it open. The TL072 is a direct replacement for older 5532 and 4558 chips, offering better audio performance at lower current draw. The good stuff.

Notes to bear in mind:
1) of course make certain the amp is unplugged and at rest for a while before digging in
2) ground yourself by touching the chassis before and while handling IC chips as static electricity can fry them instantly
3) be certain to align the curved notch on the top of new chip with that of the old

How new skills are born, good luck!

[Jerry Touval]

Dave – Thanks, very useful info.

I found a local tech who works on solid state amps and dropped the Nashville 112 off with him. Hope to have it back this week. I’ll pass your info along to him. I’m not comfortable doing this type of operation which is why I wanted to outsource it. I once fried a motherboard in a computer with a slight slip of my hand, and that was 35 years ago. I’ve only gotten more unsteady since then.

[Richard Sinkler]

I always followed Ken Fox's recommendations and used opa2134 opamps in both my Nashville 112 and Nashville 400 amps. See the following post.

viewtopic.php?t=182245

[Patrick Huey]

Your best bet is to call Peavey directly… You can send your chassis to you Mississippi and get it repaired and refurbished to factory specifications for a nominal cost