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Conrad Johnson PV11 Noise Issues

A couple months back I picked up a Conrad Johnson PV11-- I am thrilled with it. It was exactly the sound I was chasing.

After having used it for a while, I am noticing a decent hiss in the 20-25khz+ range. Not having any CJ gear, or a tube pre for that matter, previously-- I lack any context on what the normal noise floor is like on these.

Is what I am experiencing normal? If not, anything specific that needs to be looked at or should I be contacting CJ for a service.

Thanks!

Casey
cdbinz
8 responses Add your response
orpheus10
8,668 posts
 
If the PV-11 has electrolytic capacitors in the power supply, it would be a good idea to replace them if they haven't already been replaced.
cdbinz OP
1 posts
 
Thanks everyone.

I emailed CJ a month or so back and never got a response, so i guess I will call.

The only was I was able to isolate the noise was switching to a speaker I was testing with a lower frequency response all but eliminated the noise.
rbschauman
137 posts
 
I agree with Uru975...

I have a lot of CJ gear (for many years) and have always gone to them (Ed) for asking questions/service/parts.

Ed's a great guy to work with and will surely help you. Go to CJ's website and get their #.

Good Luck
zmanastronomy's avatar
zmanastronomy
738 posts
 
I don't think you can hear 20-25khz. If you can, you have better ears than me.:)
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uru975
684 posts
 
I just retubed mine from C-J and the tube set is all of $85.00, though that is with no phono tubes just for the linestage. They're great to work with and Ed who usually answers the phone is a nice guy.
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jazzerdave
163 posts
 
It does sound like a tube on its last legs. If you're new to tubes, I do recommend getting help from Upscale Audio. Bill from Morningstar Audio is another helpful resource (they're a dealer for Eastern Electric components). Vintage tube services (http://vintagetubeservices.com/Default.htm) is another useful resource, and the tubes are rated for use as Rodman suggests.

To completely retube, you'll need 2 12AX7's, 1 5751, and 3 12AU7's (unless you have the PV-llL).
rodman99999
5,981 posts
 
Yes- retube! Be certain that whatever tubes you buy are certified/graded as, "preamp/phono/low noise", "gold" or "Platinum" by a reputable and knowledgeable dealer. ie: (http://www.upscaleaudio.com/pages/Testing-Small-Signal-Tubes.html)
thorman
1,262 posts
 
Best thing to do is re-tube,since you have no idea what condition the tubes are in from the last owner..I would take that as your first step..More than likely its a tube at the end of its life.....
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