So I gave Conrad Johnson a call in regards to the voltages at certain points in the schematic. They don't offer these on the schematic because they do in-house servicing for customers. However at $150 an hour my PV10A is never going to get there especially because I fix all my own stuff.
My system has an over voltage issue which results in the NPN transistor in the primary power supply shorting collector to emitter. They read somewhere in the neighborhood of 360 volts.
I was hoping if somebody here has a PV-10A, with phono stage, if they could perhaps probe a couple points for me and let me know what their voltage is are. Mainly what I really need is what is the voltage on each of the large 20 UF bulk capacitor after the bridge rectifier.
Also I was hoping that somebody was able to get some voltages for me to find out what the AC output of the transformer is on the high voltage and low voltage test points.
If someone is able to crack theirs open I could take a picture of mine and point to a few other places where I need voltages.
All the components seem, And that is a heavy seem to be spot on. I double checked the transformer primary wiring to make sure I wasn't somehow producing higher secondary voltage.
The smaller filament supply seems to be working perfectly.
I am a newbie in this forum so be gentle.
Thanks for your time if you made it this far!
My system has an over voltage issue which results in the NPN transistor in the primary power supply shorting collector to emitter. They read somewhere in the neighborhood of 360 volts.
I was hoping if somebody here has a PV-10A, with phono stage, if they could perhaps probe a couple points for me and let me know what their voltage is are. Mainly what I really need is what is the voltage on each of the large 20 UF bulk capacitor after the bridge rectifier.
Also I was hoping that somebody was able to get some voltages for me to find out what the AC output of the transformer is on the high voltage and low voltage test points.
If someone is able to crack theirs open I could take a picture of mine and point to a few other places where I need voltages.
All the components seem, And that is a heavy seem to be spot on. I double checked the transformer primary wiring to make sure I wasn't somehow producing higher secondary voltage.
The smaller filament supply seems to be working perfectly.
I am a newbie in this forum so be gentle.
Thanks for your time if you made it this far!
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I appreciate the photo. Looks like a slightly older model than the one I have. Mine uses a triple five timer and has a black PP cap where that yellow is. What I'm trying to get is is someone who owns one to be willing to open it up and probe the two AC points next to the bridge rectifiers. I'd also like to know what the voltages are on the large 20UF bulk capacitors are since Conrad Johnson will not tell me those things. I called them directly.
So really the main things I'm looking for are the two different secondary voltages of the transformer at 120 volts primary. And I'm also looking for the post rectifier voltage at the 20 UF filter caps. If anybody has this info it would be amazingly helpful. Thank you
I sold my PV10a few years ago, sorry I can't help you measure the voltage. Why can't you measure it? Is your transformer burned out?
However, the voltage at "A" should be 317VDC, so 360V before regulation sounds about right.
My guess for the transformer secondary is 255VAC and 12VAC. I hope someone can confirm this.
However, the voltage at "A" should be 317VDC, so 360V before regulation sounds about right.
My guess for the transformer secondary is 255VAC and 12VAC. I hope someone can confirm this.
Thank you for the info on both the pv10 and pv11. I have measured mine, it is nice however to have some ballpark numbers to know when troubleshooting why Q2 appears to have 360-380 all over it. I'm currently waiting on a stock order that has some new mpsa transistors l, both non and PNP in it. Ive measure the voltage at the zener string of q1 and it lands around 310-320. Each diode tests in circuit ok.
Back story is the unit got knocked about In shipping. Was originally coming to me for a noise which after repairing the shipping damage I found was transistor noise from Q2. Replaced Q2 and all is good, with one channel. Resoldered both 12au7 sockets, perfect. Then the noise returned and q2 had shorted from emitter to collector again.
That's when I reached out to CJ and was told they do not provide the voltages on schematics due to their in house service.
Soooo I thought I would reach out and see if anyone could grab some voltages for a stranger on the internet!
Back story is the unit got knocked about In shipping. Was originally coming to me for a noise which after repairing the shipping damage I found was transistor noise from Q2. Replaced Q2 and all is good, with one channel. Resoldered both 12au7 sockets, perfect. Then the noise returned and q2 had shorted from emitter to collector again.
That's when I reached out to CJ and was told they do not provide the voltages on schematics due to their in house service.
Soooo I thought I would reach out and see if anyone could grab some voltages for a stranger on the internet!
Thanks for everybody's input. My issue ended up being Q3. It was actually shorted. Or replaced it with a more robust unit in a different style heat sink as the one that's in there is a little anemic. For the life of me I can't remember which one I put in and I used the TO220 package and heat sink that I took from a pull somewhere. If I crack it back open I will definitely let you guys know what I used. I did have to install the new package backwards and fit the heatsink with some silicone.
The unit would Work normally with a single 12 AU7 installed but the minute you installed the second one everything went to hell.
The voltage listed above was just about where I landed. The unit sounds great and tests with extremely low distortion. I do enjoy the way they see that sounds
The unit would Work normally with a single 12 AU7 installed but the minute you installed the second one everything went to hell.
The voltage listed above was just about where I landed. The unit sounds great and tests with extremely low distortion. I do enjoy the way they see that sounds