New to me PV2A

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xbartx
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New to me PV2A

Post by xbartx »

I came into possession a pretty nice looking model PV2A preamp. It doesn't look like the relay is kicking in to take it out of the start mode and output is muted.
I'm in the process of replacing all the old electrolytic caps in it, I'll start checking voltages as soon as I get the new caps ordered and replaced. Is there something else to look at, that might be the issue?
-Brad
CJ1.jpg
CJ3.jpg
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admin
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Re: New to me PV2A

Post by admin »

Welcome to CJO. Nice to have you with us. That PV2A looks beautiful. We do have the PV2 schematic in our database so you may want to try and download that to help in any repairs.
-admin
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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.
xbartx
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Re: New to me PV2A

Post by xbartx »

Thanks! I did get the schematic for the PV2, how does the schematic differ from the PV2A?
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Re: New to me PV2A

Post by admin »

Not sure but I think they must be really close as they were released less than a year apart. I would be surprised if there was any significant circuit change. But I could be wrong so you may have to compare the schematic with the board and components.
-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.
plurn
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Re: New to me PV2A

Post by plurn »

xbartx wrote:Is there something else to look at, that might be the issue?
first off - don't get electrocuted - be careful due to high voltages.

Some general simple checks I would do to try and narrow down where the issue is:
- check that it is actually powering up. Is the light turning on near the power switch (I assume that is a light?). If left on for 10 or 20 minutes does it get slightly warm - do the tubes all warm up.
- if it is not powering up, check the fuse
- if the tubes don't all warm up, maybe one is faulty.
- make sure the source is not "tape" like in your first photo - unless that is actually the source.
- try changing the line stage tubes, maybe using the phono tubes if they are compatible and you don't have other spares. From the schematics it seems that tubes 4, 5, and 6 are used for the line stage.
- listen for the relay click which apparently is supposed to be about 30 seconds after power on.
- if the underside of the circuit board is easily accessible, check for cracked solder.

Anyway that is just to get the simple tests/checks out of the way. As an uneducated guess I would expect that in 80% or more of issues people have with tube gear it would be fuses or tubes causing the issue so they are worth checking early on before replacing difficult to change components.

I am not a technician so not much more I can advise on. I think we had an experienced technician join the forum recently. I hope he considers providing technical advise going forward :)

note to admin - file "pv2 schematic (probably incorrect).gif" seems to be the same as the schematic for pv3 and only shows 4 tubes rather than 6 - so it is confirmed incorrect for pv2.

Anthony
xbartx
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Re: New to me PV2A

Post by xbartx »

Anthony,
Thanks for the reply.
It does power up, Pretty sure it is not a issue with the tubes.
The relay is not coming on, so that is what I need help figuring out why not.
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