PV1 owner questions

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GATOR
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PV1 owner questions

Post by GATOR »

Good afternoon,
I own a PV1 pre, purchased a couple years ago. Never really had a chance to use it until now. It seems I have a hiss when using the phono input only. It increases with the volume turned up. I took it to a tech, who told me the tubes were all good. I like this preamp, but I want it quieter.
Could you please make some suggestions?
Thanks.
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admin
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Re: PV1 owner questions

Post by admin »

You certainly may have a fault in one of the electronic components of the phono section. You may have to go through and test each component individually. This may be a stupid question, but I am presuming that you have tried this with another turntable/cartridge as if their is a source issue (ie turntable) then that is something completely different. Is your turntable cartridge gain requirements compatible if with PV1? If the signal from the cartridge is too high then that can certainly give you hiss that would increase as you increase the volume.
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Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
jeffreybehr
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Re: PV1 owner questions

Post by jeffreybehr »

'Hiss' like hi-frequency tape hiss, or mostly-mid-frequency noise like tube rush?
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GATOR
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Re: PV1 owner questions

Post by GATOR »

I haven't tried it with a different TT, but I have tried the TT with other amplification. The problem is definitely in the pv1.
The hiss is like tape hiss. It increases with volume and is very annoying, especially between album tracks.
Thanks for the responses, I want to get this thing fixed.
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Re: PV1 owner questions

Post by admin »

It may not be related, but I would try the PV1 with another turntable with a cartridge with lower output as if the phono gain in the PV1 is higher than the other phono preamp you tried it still might be simply that the gain in the PV1 is too high for your cartridge.
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
GATOR
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Re: PV1 owner questions

Post by GATOR »

I will try another TT, and let you know.
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Re: PV1 owner questions

Post by GATOR »

I played another turntable, same hiss is there. Don't get me wrong, it sounds beautiful, except for the annoying hiss. During the music it's only heard in the quiet passages, but between tracks it's very annoying. Any other suggestions, as my tech says it's above his abilities.
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Re: PV1 owner questions

Post by admin »

Unfortunately we do not have the PV1 schematics in our database so I can't look at that. Are you sure it's not a ground loop issue? I know these are basic questions but I find that sometimes simple common things can cause these problems and it saves a lot of time and money to rule them out. Is it one channel or both?
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
GATOR
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Re: PV1 owner questions

Post by GATOR »

It's both channels.
I have the TT grounded to the post on the PV1.
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Re: PV1 owner questions

Post by admin »

If you have narrowed it down specifically to the PV1 phono section, I think the next step is to take it apart and start testing the individual electronics in it. You didn't mention whether it was hissing in both channels or just one, but that could help you further narrow down a faulty component.
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
GATOR
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Re: PV1 owner questions

Post by GATOR »

admin wrote:If you have narrowed it down specifically to the PV1 phono section, I think the next step is to take it apart and start testing the individual electronics in it. You didn't mention whether it was hissing in both channels or just one, but that could help you further narrow down a faulty component.
Taking it apart, diagnosing, and repairing is above my abilities. Can you recommend some who might do this work for me?
Thank you. I'm willing to ship if necessary.
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Re: PV1 owner questions

Post by admin »

Of course CJ could probably do it themselves. Where do you live, if you are near MA, perhaps Spearit Sound would be able to help you.
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
GATOR
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Re: PV1 owner questions

Post by GATOR »

I am in central Florida.
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Re: PV1 owner questions

Post by admin »

If you can't do the repairs yourself, I think most likely you will have to send it in to CJ. The PV1 has a pretty nice layout with components rather far apart. You may be able to get in there with a cheap $10 multimeter and follow the phono path testing the components to make sure they are at spec.

Otherwise, this is the link your looking for: http://www.conradjohnson.com/It_just_so ... icies.html
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
GATOR
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Re: PV1 owner questions

Post by GATOR »

Is there anyone on the forum who could help with these repairs?
Thank you.
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Re: PV1 owner questions

Post by admin »

I moved this thread to the "troubleshooting" area of the site, it should get more attention there.

In the meantime, I'm guessing you have removed the cover and visually inspected the components for anything that may have "burned out"?
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
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Re: PV1 owner questions

Post by Musictek »

Before you go and tear it all apart, try different tubes in the phono stage. The 12AX7 closest to the phono inputs is the first and most noise sensitive stage. If it's still too noisy with a known quiet tube, you should start looking at the high voltage regulator and its associated caps. The PV1 is old enough that any original electrolytic caps should be suspect and probably changed on general principle. A properly operating PV1 is normally quite quiet, although you will hear hum and noise if you turn the vol control way up (much higher than would normally be case).
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