2. amps-preamps
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Parasound JC-1s Not Working

I just bought a pair of used JC-1s on Audiogon. The amps sounded fine until I was shuting down my preamp. My preamp is a tube linestage. While I was turning off the linestage, I heard some funny noise from both amps. Feeling uncomfortable about the noise, I turned the linestage back on. Surprisingly, the left channel amp did not work. The power was on but no signal.

I don't think it was the fuse. I swapped the external fuses between the two monoblocks. But it still did not work.

I wonder if this ever happens to you, JC-1s owners. Is there a switch or something inside the amp to reset? I flipped all the swithces on the back panel hoping that I could get the signal back. Still no use.

I am going to call Parasound on Monday. I know I won't have warranty since this is used. But before I call, do you folks have any suggestions? Thanks.
audiolui
audiolui OP
297 posts
 
I visually check all the glass fuses (three on the rail and two on the motherboard right behind the back panel). They seem okay.

I removed the two glass fuses behind the back panel and also two ceramic ones right behind the transformer. I took these four fuses to Radio Shack and they tested with a meter so something. They told me all fuses were fine. Now I am really concerned. I will have to call Parasound Monday. Shoot. I am in a panic mode.

Now I understand the turn on and off sequence. Thanks for the tips.
johnjbarlow's avatar
johnjbarlow
175 posts
 
Don't freakout too much. We all have made a mistake or two in this hifi life of ours. I have been lucky because I have hifi friends nearby that can loan me gear if necessary.
rhyno's avatar
rhyno
649 posts
 
one other thought: switch channels and see if the problem persists. then call parasound if it does. if the problem switches to the other amp, its your pre.
audiolui OP
297 posts
 
Yes, I put an old amp to replace the problematic JC-1 and it worked. So I know it is not the speaker or the wire, or the preamp. It is the amp. Thanks guys. I will call Parasound. I will post anything I learn from this unpleasant situation.
audphile1's avatar
audphile1
5,443 posts
 
despite the test at radioshack(I wouldn't rely on it anyway), I would still replace the fuses. Sometimes the fuse is blown right under the metal cap and you can't see it. Sometimes when the fuse blows it welds itself together again.
It's only few dollars....replace them before sending the amps to the factory.
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