Nuts! A speaker keeps kicking out!

Dear knowledgeable audiophiles,

When I have the phono setting and the turntable playing, one of the channels intermittently fuzzes out, or distorts, and occasionally even fades—only to return back to normal. I have an old McIntosh MA5100, which I love. But it is old, and it seems like something may need to be replaced, fixed, etc. I'd really appreciate any advice from anyone who has a solid idea or experience with what I will need to do to quickly remedy this problem.

Areas I've troubleshot:
• I've tried Stereo Reverse and the distortion switches to the other speaker, so it's the channel and not the speaker.
• I've tried both Phono 1 and Phono 2, and they both sound the same.
• I run the HDTV/Blu-Ray player through the tuner setting. It plays normally without any distortion. It's definitely the Phono setting in the amp or the turntable.

I recently acquired a restored Thorens TD-160, but I put a brand-new Denon DL-110 on it. It's been playing greatly for 3 months. It was professionally set up, and I don't mess with it. My gut tells me it's likely the amp.

Does anyone have any cogent advice or experience they can share with a similar problem? Is this going to be a big-money fix? Is it fixable? Any help would be greatly appreciated. Thanks for taking the time.

Sincerely,

Bill

 

Have you tried Contact Cleaner on the phono input selectors ? These tend to act out like crazy on all pres with time. Since they handle a lower signal than other inputs they are finnicky. I recently had to deal with similar problems on both my phono input switches.

 

Contact lens cleaner? Am I going to have to crack this thing open? Or is this in he back where I plug in the bananas? I must admit I've never done anything like that before. If it's simply that, does it need to be a specific cleaner, and do I apply it with a Q-tip or some other type of applicator?

Thanks for the help and the quick reply,

Bill

 

Contact Cleaner. It used to be called Tuner Cleaner. You spray this in the switches and work the switches to work it in. Also for volume controls.

"ECG RX401-16 Electronics Contact Cleaner 16 oz." from www.parts-express.com!

Swap your L/R wires from the turntable and hear what happens. Also try new wires from the turntable to the amp.

Here's a cheaper version you might be able to pick up at a Walmart - they also have some alternatives. This is one thing that a Radio Shack was good for. Your local Radio Shack, if any, might still have some.
https://www.walmart.com/ip/CRC-Electronic-Cleaner-11-Oz./16817418

 

Thanks for the clarification, John. I'll hunt for this at the hardware store tomorrow. I can't try new wires, as the previous owner put in a Monster wire setup that would need major surgery to undo. I will try the L/R wire swap. Hopefully, this is all this problem is. Thanks a lot for the assistance.

Bill

 

I had a similar problem with my Marantz 2230 a few years back. Turned out to be a bad transistor in the phono section. Replaced it and all was well. I'd try cleaning the switches first as suggested and see if there's any improvement. Sadly, it might be time to take it to a tech. Good luck!

 

John,

I did the L/R swap and the distortion switched speakers. Does this mean that it's more likely faulty wiring in the turntable?

I don't know if this is better or worse now. I liked the other idea of using contact cleaner and everything was solved.

Thanks again,

Bill

 

Unfortunately, yes. Also, it is possibly a bad cartridge. Fortunately, it's not your amp.
The next thing to check is the wiring, even if it is that custom Monster wiring. A tech should be able to pin the problem down to the cart, or the wires in the arm, or the Monster wiring, pretty easily. But some light surgery is going to have to be done. Probably not too expensive, unless you'll need a new cart.
You wrote the turntable was professionally set up. Have that person check it and fix it.

 

Check the VTF again

 

On it first thing tomorrow. Many thanks again, John.

Bill

 

Mine did that and the VTF was out of wack. Bet that's it

 

Really? This may sound stupid, but do I need a gauge for that? How do I properly check it?

Thanks,

Bill

 

Yes, get a gauge. Amazon.com: Yosoo LP Digital Turntable Stylus Force Scale Gauge led: Musical Instruments

While you should absolutely be able to measure tracking force, I'm thinking it's more likely a loose or dirty wire. I'd remove the headshell, clean the connections, disconnect and connect the cartridge leads, and make sure they're tightly secure.

 

I agree, and I wish I mentioned that. That alone may solve it.

 

Well, certainly it tells you the problem is with the turntable. If the same setup was working fine for three months and isn't now and there was no trauma to any of the cables, I'd doubt that it's a wiring failure. Could be something stuck to the stylus, have you cleaned it lately? Maybe something's drifted on the table -- it's gone out of level, anti skating is off, VTF is off: check all those, and yes, get a VTF gauge for accuracy and a lightweight, not magnetic torpedo level for checking levelnes (with a sprung suspension turntable, you do need to pay attention to suspension levelness, not just plinth levelness). Certainly removing and reattaching the connections to the cartridge pins couldn't hurt: I'd start with a stylus cleaning, a checking of the VTF and levelness, and a reseating of the cartridge pin and headshell connections.

 

never hurts to check

 

And make sure you don't have a tight little "wad" attached to the stylus. Take it off and inspect if you have to.

 

I bought some today. I don't know if it solved my channel issue, but it sure as hell cleaned out my volume pot. Thanks for the suggestion! Much obliged!

I removed the headshell, contact-cleaned the shell's male connections (although they didn't look too dirty they certainly looked better afterward), gently brushed the stylus, and took a tweezer to the cartridge pin connections. I noticed one of the connections has a slight tidge of looseness. I carefully reconnected it. That's all I did. After reattaching the headshell, I played a test LP. Then another LP. And another. And so forth. It sounds as rich and stunning as the first day I plugged my little Thorens-McIntosh rig together. Im back, baby! And I'm currently basking in the Kinks' Arthur, which I obtained the other day and haven't been able to fully enjoy due to the distortion. Yes! Success!

I'd just like to thank everyone who took time from their busy day to help me out. You saved me a 60+ minute round trip to my hifi guy and a bunch of filthy lucre. More importantly, I've learned a few valuable troubleshooting lessons while you've brought me back into my love affair with my stereo set-up. And isn't that what this site's all about?

Cheers, Blokes! I raise my glass (and canister of contact cleaner) to you!

Bill

 

Awesome! Glad it turned out to be an easy fix. Lots of times it is.

 

No kidding! Thanks for the great tips. And I'm going to grab me that VTF gauge now before I really need it. Cheers, Mate!

 

A fellow audiophile in need is a friend indeed

 

Are you sure it's not a bad connection at the headshell/cart?

 

I read once on-line how some DJ's, or other people, would take the head shell off the arm and use their tongue to clean the contacts. Actually, I've done this before too thinking it would make a better contact. What was said though is, the residue left from saliva actually causes the contacts to have a poor connection.

Just something I thought I'd mention in regards to making sure those contacts are clean.

 

Hi Bill,

I just purchased a AT-LP120-USB Direct-Drive Professional and Analog Turntable System and I am having the exact same problem. I hooked it up to my existing stereo, which is 31 years old. I have never cleaned any of the knobs or switches on my system. I think the phono button may just need cleaning with contact cleaner. I so hope that is the case. I meticulously followed the installation and operations manual. Although, I do find the setting of the tone arm balance, and tracking force confusing. Along with setting the anti-skate.

I managed to set-up the aforementioned but I doubt my technical skills. I keep thinking I've done something wrong. I'm in fear of the stylus breaking off or some other disaster happening. Can you remove the phono button? Or other buttons, for that matter, to clean them? I would appreciate your or anybody in the forums advice. Well, I'm on my way to Home Depot to get some contact cleaner. I will let you know how it turns out.

Thank you in advance for your response.

Sincerely,

Scott M.