Need PS Audio PS IV schematic

I desperately need the schematic for PS Audio PS IV pre amp.

I already called PS Audio tech support and was told that they no longer have any info on discontinued products since the company was sold. The owner's manual is available on line.

The regulator is blown. I need to know the rail voltages.

Any help would be greatly appreciated.

Art
 
Hi Greg:

I read the on line owner's manual that the (PSIVH the model # of my pre amp) has a maximum Vout of 16v rms b4 clipping.
I have few pairs of 7824/7924 3 terminal reg. ICS . (16vx1.414=22.6vpeak).
So I rigged up the regs and the pre amp is up and running now.

I think that the 6v (Vin-Vout) voltage differential is marginal. If the line voltage drops or sags the regulators would drop out of compliance.

If you could kindly email me the schematic I would like to repair the original reg. circuit and may be modify it. The discrete series regulators pass trs are MJE182/172 with MPS8599/8099 error amp transistors.

Art
 
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A signal output of 16Vrms (16Vac) is approximately 45Vpp.
That would require a PSU that supplies ~50Vdc, even when worst case supply conditions are operating.

24V regulators get very close to that.
But the input to the regulators must never drop below 26V, when both worst case ripple and worst case mains voltage are taken into account.
 
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Art,

You are very welcome. I'm very happy to hear you got it going fully again!

I have fond memories of my PS Audio gear. In 1982, my first audio system with any 'high-end-ish' pretensions included a PS-III/LCC combo along with their MC cartridge amp. PS was pretty free with their info and schematics at that time and when the PS-IV came out, I was part of a small group that scratch-built our own. That project was what provided those schematics. It kept me happy for a few years until the tube bug bit me!

My 1st really-good-sounding CDP was the early PS Audio one and I've still got several of their power regenerators around today.

I'm glad I was able to assist in you keeping one of their pieces running!

Greg in Mississippi
 
Hello Greg..!
I've got PS-IV with HCPS from my uncle and it was not on the state to work. I've changed HCPS power cords and DIN-5 Plug & Jack and Voltage is coming out. But the power LED at the right bottom was not blinking. I guessed the regulator circuit was not working and I could not find the power schematic on internet. Would you mind if you email me the schematic? I would like to repair it. Thank you.
 
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Joined 2003
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Hello Greg..!
I've got PS-IV with HCPS from my uncle and it was not on the state to work. I've changed HCPS power cords and DIN-5 Plug & Jack and Voltage is coming out. But the power LED at the right bottom was not blinking. I guessed the regulator circuit was not working and I could not find the power schematic on internet. Would you mind if you email me the schematic? I would like to repair it. Thank you.

tewbc,

I just saw your request, I will send you the info on the PS-IV this weekend.

Greg in Mississippi
 
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Joined 2003
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For memory if you use it, the phono stage RIAA section was completely passive.

Cheers George

George,

Not sure if this is what you meant, but the PS-IV used an initial flat gain stage, a passive RIAA equalization circuit, then another gain stage to finish the phono stage.

It had a third gain stage as a line stage, but could be run passive, bypassing the line gain stage, which sounded better if you still had sufficient gain.

Greg in Mississippi
 
I am also in need of the full schematic/service manual for the PSIV preamp. The user manual has schematics for the phono and power stages but they are very incomplete showing only the symbols and component numbers. I'm hoping to get a copy of whatever is available out there to help me get rid of the excessive background noise i'm getting in the phono section. Otherwise the preamp sounds great and is quiet in all other inputs.

Thanks. Steve