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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
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
swampwalker's avatar
swampwalker
5,138 posts
 
Please be careful removing and re-inserting fuses while the amp is plugged in!!! In some products, the fuse is "live" and directly connected to the AC from the wall. Your problem is fascinating and we would hate to have your experimentation and detailed reporting cut short by a "hair-raising" experience.
mikey44
60 posts
 
Any more re the Model 1 noise ? I'm considering a M1 and am curious, and am trying to read as much as possible about them.
keneallyfan
26 posts
 
Definitely don't mess with the fuses with the power on. It sounds to me like the problem may not be the amp at all, but rather the speaker you have attached to the right channel. I say this for two reasons. First, Rowland has had the amp twice and can't find anything wrong. Second, the problem exhibits itself when you hooked up the right channel in your last experiment.

I haven't read the entire thread, so I don't know exactly what you have tried, but here is what I suggest. Swap the speakers between channels. Hook up the left speaker to the right channel and see if the problem occurs. Alternatively, hook up the right speaker to the left channel and see if the problem moves to the left channel.
rleff
1,065 posts
 
I have model 6 monoblocks without any problems;on the powering up and then turning off;in my manual it references a dc offset is being detected greater than spec and the amp is turning off;I don't know if that helps you out with info but note that this thread is from 2001.
These are the best solid state amps I have owned and are on par with my audiovalve challanger monoblocks(6550'c tubes).
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