I have a pair of JC-1 monoblocks (powering my main loudspeakers) which I purchased from a friend. They are hooked up to a Conrad-Johnson 17LS tube preamplifier. I am using the single-ended RCA inputs.
I accidentally disconnected the preamplifier power cable with the preamplifier and power amplifiers on. I heard a little 'pfft' sound from my loudspeakers then no more sound.
I confirmed that there is no problem with either the preamplifier or loudspeakers by hooking up with a different amplifier. I also tried hooking up one of the JC-1s to my center channel loudspeaker using my Anthem preprocessor.
I am afraid that I fried the inputs on both of the JC-1 monoblocks. I have done the typical checks:
- No more sound output to the loudspeakers.
- Power amplifiers turn on properly, relays click then power comes on. Amplifiers still get hot.
- All fuses are intact and operational
- 1 external 12A fuse
- 4 large fuses for DC rails
- 2 small fuses in inline fuse holders
- 3 small fuses on circuit board mounted on one side of amplifier
My next step is to try the balanced input, at my friend's place, to see if that works.
I have heard through AudioGon about this type of problem blowing inputs, not sure if this is a common problem with the JC-1s.
Any suggestions on where the problem may be? Is it likely on the circuit board that the RCA/XLR inputs feed? The second guess is the side circuit board with the 3 fuses.
I don't want to send them back to Parasound for repair if possible. I live in Toronto, Canada so 2-way shipping would be a killer. Also bought second hand so no warranty.
If the likely culprit is one of the two boards mentioned above, would it be possible to purchase the input boards from Parasound and get them replaced by a qualified local technician? The side board is just mounted with screws. The back panel board would require unsoldering the wires connecting the XLR input. Any idea of the component(s) most likely to fail?
Any help is appreciated, especially those who have had similar experiences.
Thanks in advance.
I accidentally disconnected the preamplifier power cable with the preamplifier and power amplifiers on. I heard a little 'pfft' sound from my loudspeakers then no more sound.
I confirmed that there is no problem with either the preamplifier or loudspeakers by hooking up with a different amplifier. I also tried hooking up one of the JC-1s to my center channel loudspeaker using my Anthem preprocessor.
I am afraid that I fried the inputs on both of the JC-1 monoblocks. I have done the typical checks:
- No more sound output to the loudspeakers.
- Power amplifiers turn on properly, relays click then power comes on. Amplifiers still get hot.
- All fuses are intact and operational
- 1 external 12A fuse
- 4 large fuses for DC rails
- 2 small fuses in inline fuse holders
- 3 small fuses on circuit board mounted on one side of amplifier
My next step is to try the balanced input, at my friend's place, to see if that works.
I have heard through AudioGon about this type of problem blowing inputs, not sure if this is a common problem with the JC-1s.
Any suggestions on where the problem may be? Is it likely on the circuit board that the RCA/XLR inputs feed? The second guess is the side circuit board with the 3 fuses.
I don't want to send them back to Parasound for repair if possible. I live in Toronto, Canada so 2-way shipping would be a killer. Also bought second hand so no warranty.
If the likely culprit is one of the two boards mentioned above, would it be possible to purchase the input boards from Parasound and get them replaced by a qualified local technician? The side board is just mounted with screws. The back panel board would require unsoldering the wires connecting the XLR input. Any idea of the component(s) most likely to fail?
Any help is appreciated, especially those who have had similar experiences.
Thanks in advance.
