Hum/Buz fro JC1

Does any JC1'owners have this problem? Any recommendation and input to fix this problem is appreciated.

is your cable tv near the system? if yes, it may be that you have a ground loop. try disconnecting the coax cable from the cable box and then turn on your system to see if the hum is gone.
Do you own a pair, if so, do both hum/buzz or just one?
houstonreef, while I do not have the JC1, I did own the A21 and also had issues with the humm/buzzz. I found that the amp was very sensitive to how well the interconnect was seated. Only a slight mis-seat would cause a buzzz. Try wiggling the interconnect around and make sure it is pushed all the way in. I hope this helps.
Thanks for all response. First the system is connected to a dedicated circuit and the pream is Supratek Syrah (tubes). I am not sure it may be possible ics. I disconnect the powercord of the pre but still hear the noise. I then unplug the ics between pre and am. As the result the noise disappears. Any ideas?

try cheater plugs on the amps to see if the hum thru the speakers stops
Houstoneef, what components do you have connected to your preamp? Try disconnecting one component at a time from the preamp and see if the buzz goes away. If it does that's your problem. To fix the problem get a ground eliminator and inset in circuit between the preamp and the IC connected to the problem component.
houstonreef, I had the same exact strange behavior with my A21/P3 setup. I could never figure out what the issue was. I know this does not help but I eventually got rid of my Halo gear. I wonder if this is some sort of design issue with the Halo products?
The pre is connected to PS audio Dac. I had disconnected the ground wire on the power cord of the pre but the problem is till there. Downunder and Seadogs1, can you explain to me how to do it.

Houstonreef, have you tried what I recommended?
Audpgile, there is no tv near by. there is one cable jack right behind the componet rack but the cable jack does not connect to anything. Audphile1 what do you recommend me to do with this cable jack?
Do nothing with the cable jack. You may still want to try disconnecting the coax cable at its first entry. If you have a ground loop that causes this humming, you will know it when you take out that cable. Your amp may not be sensitive to this ground loop, but your preamp may be, since you say the noise is gone when you disconnect the preamp from amp. Try it, if it's not a big deal. Other than that, it could be your preamp that's causing this problem. Tubes, other things......who knows. Also try a cheater plug as recommended above.
cheater plugs are just plug ends with the ground removed. you can buy them in hardware stores. It allows your 3 prong male plug to plug into a female end with two male prongs on the other end
Downunder, i did the same thing with 3 prong female by disconnect the ground wire so which means that there is no ground feeding the amp.
it could also be that your rca jacks from preamp to amp are not seated all the way in the amplifier input jacks. If you are using locking type rca connectors, then you may want to make sure they're pushed all the way in. Some input jacks make it seem like they're in all the way, but in reality there's still room.
Also, try connecting your cd player to the amp(but don't hit play) and see if that causes the same buzz as the preamp does. If not, your preamp is causing your problems.
The best info I have seen about cheater plugs is not to use them. The shock from an ungrounded chassis can be lethal. If the interconnects are well made and properly seated, the next step would be to use a good quality power strip and plug all the units into it. Generally that should take care of the problem unless it is a real design flaw in one of the system items. Good luck.