I have a Peavey 8.5 power amp on my bench and I need the schematic if anyone out there has one. Help please. Thanks.
PEAVEY PV-8.5C SCH Service Manual free download, schematics, eeprom, repair info for electronics
If you can't download it, I can email it to you instead.
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There is a PV-1.3k schematic on eserviceinfo.com
8.5 has lower rail voltage and fewer output transistors.
8.5 has lower rail voltage and fewer output transistors.
Here's a link to my Box account for downloading.
https://app.box.com/s/fkib588kz6o6lvhewfw7gfh0djkxplst
First you can ALWAYS get any schematic right from Peavey customer service.
Here is an unencumbered schematic:
http://bmamps.com/Schematics/Peavey/Peavey_PV-8.5C_Service_Manual.pdf
jo: the 1.3 may be similar but the part numbers will all be different as well as the layout.
Here is an unencumbered schematic:
http://bmamps.com/Schematics/Peavey/Peavey_PV-8.5C_Service_Manual.pdf
jo: the 1.3 may be similar but the part numbers will all be different as well as the layout.
Point to the moderator who moved this:
The PV-8.5k is not a guitar or keyboard amp. It is a PA amp. It has higher fidelity than my dynaco ST70.
I've had trouble with elektrotanya.com the original link.
The PV-8.5k is not a guitar or keyboard amp. It is a PA amp. It has higher fidelity than my dynaco ST70.
I've had trouble with elektrotanya.com the original link.
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Agree that it belongs in "Solid State" , not in Instrument Amps.
Unless you want to move all APEX Audio stuff over here, that is 😉
Plus all other >150W amps 🙂
Unless you want to move all APEX Audio stuff over here, that is 😉
Plus all other >150W amps 🙂
RIGHT ON!!! for PV service--they are the best! I wish other manufacturers would take note of this, and YES, it DOES make a difference in the next purchase I make.
Somewhere on the power supply board of this Peavey 8.5, is a short, that i can't find. I'm missing my -16VDC to the op amps , funny thing is, if i unsolder and lift up the negitive side off of the of C123, the -16 volts returns on that side . I have replaced so many parts it aint funny no more. That just one problem . Problem #2 is on the other side of the board. Q200 which is a Driver for the final outputs transistors gets extreamley hot it is a 15030 it is fed by +15 VDC which comes in on the collector. I have checked all surrounding major componets , diodes and transistors in the vacenity of these two problems and still no relief in sight. Thanks for all your help.
After the output transistors shorted, the driver transistor shorted, and rail voltage rampaged through my PV1.3k. Almost all the 50 v tan ceramic bypass caps were shorted, some of the green 50v round caps were shorted. If the two ends of a capacitor are at the same value in audio, it is pretty likely the cap is shorted. I don't have a capacitor tester, just if anything connected to one was nailed to ground or rail, I replaced it. Besides capacitor testers work at 2 v and the circuit works at 15 or 75 or higher.
The op amps were shorted except the DDT LED driver. I think the previous owner had reset it multiple times; OT's were shorted on both push and pull sides. The VI transistors were shorted.
I replaced 124 parts. I only paid for the OT's, some MJE15031/2 predrivers the op and transconductance amps, and the 4000 ohm power resistor. The rest of the parts came from salvage from old TV's and PCAT power supplies. Its $8 freight a box to order anything here, so it is a lot easier to cut up something for a $.35 part than make an order. I pull parts and sort into labled bags while listening to records, so my mind is not fully occupied while doing that. Then when I need something, pull that decade baggie, thumb down to the right value, there you are. Or parallel some other value parts sometimes.
Fixing the PV-1.3k was not a productive exercise, but I learned a lot and it is more interesting than crossword puzzles or television. VI limiters, DDT, jfet function, Peavey flying speaker return (ground), I put some additional fuses and sacrificial zener diodes in to keep rail voltage where it belongs if there is another failure, and improved the self-melting "protection" crowbar that won't blow a breaker. Rail fuses will go now, in clips mounted on the back of the output transistor board.
Have fun.
The op amps were shorted except the DDT LED driver. I think the previous owner had reset it multiple times; OT's were shorted on both push and pull sides. The VI transistors were shorted.
I replaced 124 parts. I only paid for the OT's, some MJE15031/2 predrivers the op and transconductance amps, and the 4000 ohm power resistor. The rest of the parts came from salvage from old TV's and PCAT power supplies. Its $8 freight a box to order anything here, so it is a lot easier to cut up something for a $.35 part than make an order. I pull parts and sort into labled bags while listening to records, so my mind is not fully occupied while doing that. Then when I need something, pull that decade baggie, thumb down to the right value, there you are. Or parallel some other value parts sometimes.
Fixing the PV-1.3k was not a productive exercise, but I learned a lot and it is more interesting than crossword puzzles or television. VI limiters, DDT, jfet function, Peavey flying speaker return (ground), I put some additional fuses and sacrificial zener diodes in to keep rail voltage where it belongs if there is another failure, and improved the self-melting "protection" crowbar that won't blow a breaker. Rail fuses will go now, in clips mounted on the back of the output transistor board.
Have fun.
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Holy sh*t!!! 124 parts??? I admire your patience---I think I wouldda just sh*t-canned the whole thing!! Does it work now??
Yes. It was cheaper than a college course, and there is no teacher/lab assistant standing around trying to prove they are smarter than you. Thanks to the kind people on diyaudio for help, especially Enzo.
But I've deferred installing rail disconnect Mosfet protection in the PV-1.3k while I redesigned a 120 W amp that fits my living room. I finished that last week, drew the schematic, still need to take pictures.
650 W/ch of the PV-1.3k is something I might need if I play park gigs, and I'm only playing 300 seat halls occasionally. On acoustic piano at this point, I'm not singing pop music in public yet. I don't have an instrument truck or bandmates yet, either.
The rail disconnect mosfets will not only protect the speaker, they will protect the other 19 output transistors if one of them shorts. $4.30 a transistor, that is an investment. The original crowbar protection in the PV-1.3k was a failure. Instead of blowing the breaker when DC on speaker occurs, the triac melts the traces off the PC board. Did it again in front of me when a stressed used OT blew up. If MJ15024/25 (what OT peavey used) reads <0.450 v CE, it is going to blow up under 180 v. I was able to reuse two MJ15024/25 as drivers, the other 18 were trash.
Hint, don't connect the triac to the OT's until you are done. I had one SPS (diac) blown too.
But I've deferred installing rail disconnect Mosfet protection in the PV-1.3k while I redesigned a 120 W amp that fits my living room. I finished that last week, drew the schematic, still need to take pictures.
650 W/ch of the PV-1.3k is something I might need if I play park gigs, and I'm only playing 300 seat halls occasionally. On acoustic piano at this point, I'm not singing pop music in public yet. I don't have an instrument truck or bandmates yet, either.
The rail disconnect mosfets will not only protect the speaker, they will protect the other 19 output transistors if one of them shorts. $4.30 a transistor, that is an investment. The original crowbar protection in the PV-1.3k was a failure. Instead of blowing the breaker when DC on speaker occurs, the triac melts the traces off the PC board. Did it again in front of me when a stressed used OT blew up. If MJ15024/25 (what OT peavey used) reads <0.450 v CE, it is going to blow up under 180 v. I was able to reuse two MJ15024/25 as drivers, the other 18 were trash.
Hint, don't connect the triac to the OT's until you are done. I had one SPS (diac) blown too.
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To Rayma , I will swap those two caps on Monday, the ones that control the + & - 15 VDC rail voltages. Thanks for your help. To Indianajo, Man I so feel your pain !!! I'm gonna try swapping those 15 volt supply caps and see what happens . I seen a schematic here a while back that had a crow bar circuit in it that was controlled primarily by a triac, interesting circuit. I too, try to rob parts of off other used discarded items. And like yourself I'm a musician , a drummer and vocalist and I work during the day as a electronic tech. You had to have had some kind of patience fixing those items. If I could just isolate my problem I could probably fix it. Thanks for all of your input.
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