Parasound JC-1s Not Working

In the future be sure to shut down the amps first. Turn on sequence should be the preamp first. When shutting down your system, always turn off the amps first.

i think there are some B+ rail fuses on the output stage.

WITH POWER OFF and the amp unplugged (damn JC1s and that stupid illuminated on/off switch), take the cover off and look on the back panel for some fuses. i suspect you'll find some that are blown.

You must shut down your amps FIRST, before the preamp and sources. This order is mandatory, especially with tube preamps. Otherwise you risk sending DC into the amps and damaging them and/or your speakers.

Did you swap ic's to see if it is indeed an amp issue or preamp issue?
If not, you need to do this first.

There are two 12amp fuses on the mother board, you may have blown one or both. After you remove the top, you need to pull the fuse's and check them with a meter as they are ceramic and you can't tell if they're blown by looking at them.

And as stated, amps should be turned off first with pre's volume at zero and mute on.

Turn the JC-l off, unplug the unit, remove the top. When you look down into the unit you will see some rail fuses. Replace the fuses with the same value. The unit should work fine. To repeat:: When using a Tube Preamp the turn on sequence is first turn on the Preamp and then the Amps. The turn off sequence is first turn off the Amps and then the Preamp.

One of my JC-1's died. When I replaced the rail fuses it worked fine. That was over two years ago and they continue to work just fine. I keep a supply of replacement fuses on hand just in case.

Good luck and good listening.

Thank you all for your quick responses. I am going to open the amp and check out the internal fuses. External fuse is okay as I swapped them already. Will let everyone knows.

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.

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.

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.

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.

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.

But I also tested all the fuses myself with a meter set to ohm. They all had readings.

Let us know what you find out. I'm not a JC1 owner, but may be soon and would be interested to see what happened and what your experience was like with Parasound's customer service/support.

I just shipped the amp to Parasound. So far the tech seemed fine and quick giving me RA # to return the amp for repair. I have yet to find out how much the repair is going to be. The tech said the labor is $75 per hour. Update will follow.

Thanks. Please keep us informed.

Regards,

I just got the amp back and have not had the time to listen to it seriously. But it is working though. The repair cost is under $200. The turn around was quick; it took about several days for them to fix,test, and ship it back.

I am happy with the service and the staff there were generally professional and easy to deal with.

All the fuses were fine. No fuses were blown as I tested them previously. The tech told me the speaker relay was burned. They replaced that and a few transistors.

They kept telling me the importance of turn on and off sequence. Well I am following their recommendations exactly. I just don't understand why I didn't have to do this on-off sequence with my other amps which are BEL Mk V.

I wish Parasound put this on-off sequence recommendation in the owner's manual so that I didn't have to go through the trouble. Thanks to everyone who provided inputs to this matter. Happy listening.

turn on sequence comes down to 1 thing: amps on last, off first. do that, and no worries.

Audiolui are you in USA?

@bob0398 Did you look at the date on these posts? 17 years old!

 Thanks. No.  I read 02-24... and jumped to a misunderstanding.