2. amps-preamps
  3. 1005432452

Help, Strange Static Sound Recurring

I am a newbie. I have a nice hand-me-down system (from my Dad), a Jeff Rowland Model 1 Amp, an Audio Research LS3 preamp, Thiel 3.6 speakers, and if it matters, a Theta Data Basic with a Theta DS Pro Basic III.

When I set it up, it was fine. After a few weeks, I awoke to hear loud white noise (static) coming from one channel. I had left the system powered up, but the amp was off and the static persisted. I could not turn the amp on. When I would push the power button, it would light up, but would not "catch" and stayed unlit.

I called Rowland, and sent the unit in to them. It checked out perfectly. I hooked it up again and it was fine, only to repeat the problem. The Rowland people were flummoxed. They had played it continuously for a long time with no problem. I sent it off again, but no problem found.

I talked with a local (Minneapolis) audio guy who speculated that it could be that the power coming into my house is weak or inconsistent. I then tried a computer UPS (uninterruptible power source), and I thought the problem was solved, but alas it recurred.

Someone at one point mentioned that perhaps the 3.6's were a bit much for the amp, but he wasn't saying that was the cause.

At times I have unhooked the speaker cords, swapped channels, changed fuses, etc. Sometimes, unhooking and then reconnecting the speakers seems to make it work, but then after a few weeks, here comes the static again.

Anyway, it is frustrating and the wife wants me to sell the whole system. I just bluebooked it at 5K. I might do so, but I'd love to solve the problem.

Any thoughts? Anybody wanna buy it?
hyoster

Showing 5 responses by hyoster

hyoster OP
6 posts
 
Thank you sugarbrie. Can you recommend an audio power center?

I tried swapping the pre-outs and the static still comes from the same channel. I also had the preamp totally checked out by the mfr during this process... no problem found.

Any other thoughts?
hyoster OP
6 posts
 
You guys are the best! I'm tied up tonight, but tomorrow will begin with the systematic experimentation.

I have never seen a group with such thoughtful advice on any subject. Again, I thank you for the technical and spousal advice.
hyoster OP
6 posts
 
I took Bob's advise and cleaned all contacts with denatured alcohol. I plugged the amp back in and ... no power!

After checking around, I found a blue wire from the PC board on the side to one of the connectors on the back had become threaded between two speaker wire contacts. When I moved it, the amp powered up fine.

Then I hooked up everything else, and at least for now, the stereo sounds GREAT!!
hyoster OP
6 posts
 
Well that success was short lived. We enjoyed music all Saturday, then went out for dinner. When we returned the sound was back. I haven't done anything with it.

Bob, who do you know in Minneapolis?
hyoster OP
6 posts
 
Yes, I have isolated the problem to the Amp, I think. Here is a symptom that I am hoping will lead some of you toward solving this problem.

After I cleaned the contacts, I plugged in the amp to the power, and it would turn on and off. Then I attached the left speaker, and I could still turn it on and off. Then, I attached the right speaker, and boom here comes the static. And when the static noise is occurring, the amp will not power up. The switch does not catch when depressed.

I had the top of the amp off, and decided to monkey with the fuse to see what would happen. I unscrewed the top of the spring-loaded fuse holder, and the sound went off, and a red light lit up on the circuit board near the fuse. Then I re-engaged the fuse by screwing in the top of the fuseholder again, and the noise was gone!

I decided that this was strange, but that I would just keep the screws out of the lid to the amp so I could do this if I had to. I ran the amp for several hours with no problem, then turned off the power supply, effectively unplugging it from the wall. When I turned the power supply on again, there was the static. So I repeated my fuse trick and voila, no static. After playing for 10 minutes, the static returned, and I powered down the system.

Does this help in the diagnosis department?

Thanks,

Greg
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