Conrad Johnson PV-10a hum. Any advice?

cchean · 13th June 2010, 08:55 AM

Hello Folks,

I have a CJ PV-10a preamp that has a loud hum. It is constant and present in all source inputs. I am thinking it needs a recap job done or maybe a voltage regulator replaced. Am I in the right direction? Does anyone have the service manual or schematics for this preamp? Thanks.

Carlos

SY · 13th June 2010, 11:32 AM

Both channels or just one?

Have you swapped out tubes?

cchean · 13th June 2010, 03:52 PM

Both channels. No, I have not tried anything yet.

Palustris · 13th June 2010, 04:52 PM

I think you could be correct about the voltage reg. I would send it back to cj for refurb. and updating. They are reasonably priced, quick and very professional. I have sent back both my PV4 and PV5 to cj at one time or another.

SY · 13th June 2010, 05:19 PM

Quote:

Originally Posted by cchean

Both channels. No, I have not tried anything yet.

Two possibilities: a ground has come loose or the power supply is fritzed. I'd trace the ground circuits carefully, and make sure everything is still well-connected. Especially true at connectors, screws, lugs, stuff like that.

13th June 2010, 08:55 AM	#1
cchean diyAudio Member Join Date: Dec 2008	Conrad Johnson PV-10a hum. Any advice? Hello Folks, I have a CJ PV-10a preamp that has a loud hum. It is constant and present in all source inputs. I am thinking it needs a recap job done or maybe a voltage regulator replaced. Am I in the right direction? Does anyone have the service manual or schematics for this preamp? Thanks. Carlos

13th June 2010, 11:32 AM	#2
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Both channels or just one? Have you swapped out tubes? __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

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13th June 2010, 03:52 PM	#3
cchean diyAudio Member Join Date: Dec 2008	Both channels. No, I have not tried anything yet.

13th June 2010, 04:52 PM	#4
Palustris diyAudio Member Join Date: Aug 2006 Location: Cape Cod	I think you could be correct about the voltage reg. I would send it back to cj for refurb. and updating. They are reasonably priced, quick and very professional. I have sent back both my PV4 and PV5 to cj at one time or another.

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