It's amazing to watch someone trouble shoot and repair an item at the component level. That's totaly old school. Nowadays the techs just replace the entire board. Nicely done.
As Always Tony you are teaching the world how to trouble shoot problems systematically. This is something very few people these days know how to do. Excellent trouble shooting video as usual. Thank you for teaching how to systematically go through and figuring out the problem. I hope the family is doing very well.
The CS1200 is a heavy beast. My channel gain knob broke off at about 90% and I eventually sold it along with some Cerwin Vega horns with 15" woofer PA speakers. It was a loud system.
It always gets me that one simple component, like one diode, can trash a huge amp. I’ve had this endless time with all sorts of equipment. A part that costs pennies trashes a valuable piece of equipment. Anyway, that aspect adds to the personal satisfaction when the job is done. Thanks again for a great video.
It's the same model they have in my local cathedral church. They use it to drive three giant speakers pre-channel. It's a beast. Thanks, Tony. I clicked on the video the moment I saw the word Peavey and 1200.
Those peaveas of that era are total BRUTES! you could put a dead short between each channel and it'll just go into protect while there's a short! I've seen people drive speakers of all ohm loads, wattages,etc.. and that amp will take it all.
I used to do guitar and amp repair in the late 90s. Peavey didn't make the best sounding gear, but it was good enough. The upside is that they durable as hell. The only problem I've ever had with 70s through 90s gear were cold solder joints or blown speakers. Brings back a lot of good memories seeing this.
The CS1200 and 1200X are one of my few favorite peavey products. They’re great amplifiers and they sound great if you modify the pre driver stage a bit. They sound a little flat stock. Same thing with that same era of the CS800. Great affordable amps.
I am jealous. I payed 90 buck for a cs 400, and rebuilt it. what a beast. you have a really big beast. one interesting thing about these amps is the speaker damping factor, meaning when the amp sends a signal, it does not allow the speaker cone to continue movement after the signal event. rater interesting to watch.
Incredible repair.... gotta give props to amps that are 2 ohm stable.... that's why I like my Crowns. I'm not loading them at 2 ohms, but it's nice to know I could... !
I used to run 12 big racks of these back in the day.. that was pretty much the stock fault.. the fan control circuit failed.. they went bang due to heat.. which is why you often see them with small strips of paper stuck in front of the grills on the front in pictures of big rack mount systems running these. Otherwise they were great amps... but damn heavy when you have 8 of them per rack !!!! (make sure to buy the venue lifting crew some beers if you like your gear in one piece after the show)
I love the old Peavey amps I have a PV 1.3 k rebuilt the whole thing all new resistors transistors diodes caps filters all the way down the line it took me about a month to rebuild Plus also waiting on parts. when you order parts from PV you have to look at the schematic and give them each part number it's crazy.😂 Got to know all the people at PV pretty well. Grant Brown said to me why are you rebuilding this amp when you can buy a new one with a lot more watts and I said because you can't beat the old PV amps they're built like tanks.😁 The PV 1.3 k weighs 100 lb and it has one huge transformer in it to run both channels LOL. 2,110 watts at 2 ohm load it's a powerhouse. I have a lot of time and money in it and I'm not getting rid of it for nothing 😂 if I was you I would keep that amp and never get rid of it. Brand new when the PV 1.3 k first came out the price tag was $5,000.
When I had a CS series in the shop with a problem on the amp board, it was common practice to replace all the diodes on the board. Diodes are cheap, and they were a high failure part in those.
Peavey is a victim of their own success when it comes to these old CS series amps. A lot of pro sound people are snobs and say "Peavey is junk". But what they are talking about are amps that are close to 40 years old in some cases and have never been serviced.
Yes was thinking the same. The old Peavey amps are known to be really good and reliable... but yeah there is always a lot of uneducated opinions in the audio field, especially in the "pro" and "high end" world lol
I've serviced a lot of Peavey over the years. Wasn't always the best sounding gear. However the reliability was good and mechanical design was solid. Their customer service was always fantastic too.
Hmmm... I don’t know about that. I’ve seen a repair video recently that got me absolutely appalled, where *a freaking burnt LED* took out the whole unit. It was from the IPR series, if I remember correctly. P.S.: yep! Here you go: th-cam.com/video/HCrcbHSnogc/w-d-xo.html . It’s simply unbelievable!
What I love about electronics is that if there's something wrong with it it's usually a really simple and cheap fix. Most things that end up not working are due to electrolytic caps drying out.
Damn! wish you did this video about 15 years ago LOL. May have saved me about £200 on a repair bill when my CS1000X blew, Awesome and very interesting video thanks for sharing.
Tony you are a frickin genius, i watched this whole video and 11 of your other videos, i really enjoy the explanation, the way you run through everything and refer to the schematic, very educational, you are the best, no one i know explains things like you and it is fairly easy to understand, thank you., this was fun to watch,..
What a great tutorial on using a Dim Bulb Tester. Just what I needed. I just cautioned my family and friends on the dangers of AC (even in small SMPSs) and the need for a DB Tester. Thanks! From the look of the grunge inside, I would think that amp had been used as the house amp in a bar. I would also think that it smelled pretty bad. I ran pro sound in the late 70's through the 80's. We had a good bit of Peavy equipment. It was cheap enough, but it all had really harsh high ends. We changed brands, as the company grew. I also had an electric guitar amp head and 4- speaker box. It was solid-state and 60 amps, IIRC. Inside the head, there was a funny little quality sticker that said something like "Made by beautiful virgins, in Meridian Mississippi. No kidding. Maybe someone knows the exact quote. It would be fun to know exactly.
I have two CS-900s. Going to take both of them apart and replace the power transistors. One has an issue where one channel clips all the time with only a little input. The other amp sound distorted all the time. So, I'll try that and see what that gets me. Great video!
Good job saving the old iron :) And great explanation of the troubleshooting methods and what you can "see" by just using the dim bulb.. i love it, its my favorite and first-to-go tool for troubleshooting almost everything..
any time you even THINK a Peavey has failed to DC on the outputs.... Replace that SAC187 at the output. They are decent amps, rock it. Repaired hundreds of that era CS series.
Appreciate your video alot it helped me with my repair to my cs1200 , I'm a big fan of peavey most of my gear is peavey and they work real great.Thanks 👍
I used those a lot back in the 80s/90s there's a law, similar to ohms law that applies to those amps. The CS series cost roughly $800 for an 800 watt and weighed seemed like 800lbs. You almost couldn't stop them though.
Nice vid. I remember using those amps back in the day at a dance club. We had the CS1200X powering 4 JBL MR15's (2 per ch so at 4 ohms per ch). and then had 4 Silver CS600's bridged powering 4 JBL TR215's. (yes we blew the horns in the TR series several times but woofers were just fine). LOL Then a QSC RMX1500 pounding 3 8ohm 18inch Peavey Scorpion subs. Granted this was in 2001, owner was to cheap to buy decent speakers. LOL But that amp rack was built like a freaking tank. Weighed as much as one to cause I carried those bad boys up two flights of stairs. 1 at a time, 10 min break in between!!!
I repaired a small peavey guitar amp years ago, and inside the power transformer was a heat sensitive fusible link, interwound with the primary winding. In theory a reasonable protection idea but it threw me a curved ball thinking that the transformer itself was open. Shorted that and got the amp working. A real trap for young players!
Fan mail.......LOL!!! Ok, I commented on this before saying I hate you cuz you got it for $20. The friggin KNOBS are worth the price!!! That aside I want to say I've been through MANY of these and own at least a half dozen-both reg. and X versions. Stellar amps btw. Mine all worked when I got them, but much of your troubleshooting could have been averted when you 1st took it apart to clean. These amps are old enough now they're quite dirty, so known history or not the 1st thing I do is tear em down to clean, and OHM EVERYTHING OUT--paying particular attn to all power devices-including those diodes. If you'd have done this you would have caught the diode and saved yourself a bunch of time. I read in the comments those are a high failure part-even though I've never seen it. Still an excellent practice to check them when tearing down/cleaning. On a diff note I'm glad you checked those caps for the lower voltage supply. While I'm aware of the hot running low speed fan resistor I wasn't aware of it cooking the snot out of that neighboring cap. Now I'll have to check all of mine.....smh. I loved your using a 50 watt resistor, as well as explaining how the fan switching speed circuit works. X versions claim to be 2 ohm stereo stable-I'd never run one that way for extended periods.....period. Love to see you tackle a peavey 1.3K as those, are a nightmare..... :)
EXCELLENT Video! You really understand your stuff! I am sure you would make an Excellent Electronics Teacher. I took several Basic Electronics Courses back in the 70's and worked on Radio and TV's for a short while. I still stay a little involved with electronics in the " Ham Radio" end of things. Looking back I I wish I had learned the theory and practice of electronic from more learned people, if you have instructors that are not sure of what exactly is going on in a given circuit, the student also is not going to end up being certain either. This is the first Video of yours I have watched and I will be looking for others now. Again, Excellent video in all regards. Thank You!
I found Tony's channel because I needed info on how to service my Pioneer SA7500, I've been hooked ever since. Even started to watch from the first video he put up and learning lots.
The reason you didn't get a bright bulb with the power amp separated from the preamp is because you opened the feedback circuit. The shorted diode pulled the speaker line all the way to the power rail, but without the feedback there was nothing to turn on the opposite bank and cause a short across the power supply. (Also, no load on the amp, so, no place for the shorted power rail to go.)
That's cool and everything you fix that amp really good! I have a suggestion you go through all that trouble shooting and showing everybody how you fixed it and you don't bother to show buddy speakers hooked up to it.
Fantastic ! I happen to be using one of these and a 1000. Love them! I also have 2 of the DECCA 528's that are in serious need of repair, a DECCA 724 still in service ... WOW!!! What an amp. Also sub to your channel... I still push my luck on repairing these steel tanks also. Thanks...
The DECA series was one of the first amps to use a PWM switching power supply. Now most amps made use that topology. The DECA amps came out in the 1980s. Way ahead for their time. Digital Energy Conversion amplifer.
Why not hook it to the speakers to see what it sounds like? It looked like you checked for DC on the outputs etc. so it probably sounds fine and works fine.
I picked up a CS-2400 Amp from a friend who does storage lockers he was going to put in dumpster, but he gave it to me. I brought it back to life (bad safety relay) and I use it i my home system ,I got Cerwin vegas D9 on it and they sound great .
Thank you very much That was some very helpful information there i repair one of those back in Jamaica about three years ago the problem was with four of the output transistors.
I am really happy to see your equipments and way you work perfectly with the diagram and explaining about the corns and prons of it and rectify the faults skillfully with all the details do you repair music systems like GR-7(Sony)?
the Peavey stuff is pretty rugged, the Spec's aren't great tho this may seem somewhat incongruous, but I run a Crown K2 @ 500wpc/8ohms into Klipschorns that need 3 watts .. :)
I had a CS400 and the output transistors were gone, shorted...I did not fix it...I scraped it..and took all the good transistors and various things..and you are right it had one single massive transformer..
great video..great instructor,(although first 10 minutes seemed to be waist...you proved a short so how would the triac ckt going thru thermo switches cause that???maybe no primary voltage but not a short...anyway from then on excellent..im trying to repair a peavey -2600 and a gps 3500..., 2 questions..will a cap that is failing esr also test bad with cap test found on most dvm,s? can you talk about peaveys ddt circuitry, because I have a ddt light always on and cant see the ckt labled in the schematic?i know it haS SOMETING TO DO WITH COMPRESSION AND LIMITING INPUT..BUT HOW DOES IT SENCE?
I think that amp is made for professional high-end commercial uses such as DJs, Karaoke Bars, Hotel Ballrooms, Nightclubs, Public Address Systems, Conventions, Rock Concerts, School Auditoriums, Performing Arts Theaters, Stages, Studios, Fairs, Bands, and similar applications. That unit was not made for home stereo use.
Stephen Hinkle that doesn’t stop me from using a bogen m600 to power the subwoofers in my home stereo. Which is designed for the same purposes these are. They aren’t designed for it, but boy do they do a good job of it. Just at the expense of lots of energy usage. Mine needs a dedicated 20 amp circuit
I used these often doing sound years ago before Class D amps took over. If you ever run across any Crown Macro Techs to work on they are really interesting.
Peavey are pretty good if you contact them asking for schematics & service info. I emailed them for info on a bass amp, sent me the schematics with the proviso I didn't re-publish them etc.....DA
Yeah when I rebuilt my PV 1.3 k. Peavey sent me all the schematics so I could order all the parts.When you order parts you have to order by the part number on the schematic. You can't just tell them what part you need 😂
Would a capacitive dropper be a better (less heat) way to power the cooling fan, or would that, somehow, be dangerous? Thoughts/suggestions? I thought the OEM resistor was poor engineering, at best, and, maybe, a little nuts... Your resistor solution was much better than the original and looks like it will work well and be safe.
Tony. Did you ever think of troubleshooting one channel at a time by pulling the wire off the breaker. Just a thought for future troubleshooting as it would be fast
How is it so quiet? Fan speed wise.. I have a Peavey CS 1000, and the fan is ridiculously loud! Always runs flat out speed, and can clearly hear it over the audio, when at comfortable levels in a room
Ich liebe deine großartige Arbeit. Wieder mal direkt das Problem gelöst. Unglaublich !!! ( Wie groß muß ein Schaltplan sein, um Dich mal herauszufordern?! ) glg.
Can you tell me or recommend, where to buy this peavey cs3000 Circuit Board, because it just burn. I can see the model was P2500AMP on the board. Thanks
i'm from mumbai-india. had made 50+50 rms using 3055/2955, 25 years back in my electronics diploma, probably had the highest o/p compared to 3-10w ready made pieces, really loved the fully analog sound response, now using a 50*2+100w aliexpress class d, with optical/coax .
3/4 valume settings should put the led lights at yellow turn the nob more /red comes still not peeking the 1 red top red light turns on when u drive the amp going for 2400watts
As soon as we saw the schematic, it occurred to me that if you have two identical channels, you should have been able to isolate bad channel much more quickly.
Cool stuff, thanks for the informative video! I have a question though. Moving the power resistor from the board to a more remote location is certainly a good idea but are you sure these tiny yellow wires can take the load? (beginning @35:12)
Go back and you will see and hear that those wires carry the current of the fan. @37:52 you will see that the Maximum current draw of the fan is 0.28 amp which just about any wire will handle.
Very nice video! But i wonder why this power resistor got so hot if it is shorted after the amp is on. Did you check the opto insulator and the triac ? If they don't work the resistor would not be shorted, it would get hot, the fan would not get full power, and maybe cause thermal damage to the power transistors.
Great question! The purpose of the resistor is to limit the power to the fan to make it run slower. This quiets it down, so you don't hear the loud fan at lower volumes. If the amp begins to overheat at higher volumes, the thermal switch will close and cause the TRIAC to gate on, shorting out the resistor and applying full power to the fan (which will then be very noisy). In most cases, the fan will run at low speed through the resistor. When Peavey designed the amp, they used a power resistor that gets very hot, due to the amount of power it has to dissipate. To make matters worse, they mounted it on a PC board right next to the power supply capacitors. Going to a larger resistor and moving it off of the board allowed everything to run much cooler. The same problem exists on the Soundcraftsmen amp I restored (check out the video) . Hope this helps to explain things. Thanks for watching!
yeah , and with no load this amp sits there and runs the fan in slow mode but power resistor is working overtime....(kinda of a stupid circuit)..and who knows amp was probably left on long periods of time perhaps days and weeks at a time, waiting for signal.
I have one I need to look at. These go through a self check on startup. If it self checks ok a relay for each channel can audibly be heard activating. I'm only hearing one on mine, hence only half is working. Where are those relays located in these units?
Hi there, I am servicing an old Krell Power Amplifier with a push pull circuit. It consists of 14x NPN plus 14x PNP transistors. What puzzled me was that the PNP ones had an average hfe (Beta) of around 45 whereby the NPN side measures around 115. My first question: Shouldnt the push and the pull side be matched to have both the same level of amplification or is that somehow taken care by the driver setup? Secondly: the amplification range on the PNP as well as on the NPN side various greatly( 16-67 NPN, 105-168 PNP side) is that caused by aging ? Could i still leave it or would it be risky to operate the amp under such condition? I believe it will cause an uneven distribution of load but under normal load that might not be too bad ?
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It's amazing to watch someone trouble shoot and repair an item at the component level. That's totaly old school. Nowadays the techs just replace the entire board. Nicely done.
As Always Tony you are teaching the world how to trouble shoot problems systematically. This is something very few people these days know how to do. Excellent trouble shooting video as usual. Thank you for teaching how to systematically go through and figuring out the problem. I hope the family is doing very well.
The CS1200 is a heavy beast. My channel gain knob broke off at about 90% and I eventually sold it along with some Cerwin Vega horns with 15" woofer PA speakers. It was a loud system.
It always gets me that one simple component, like one diode, can trash a huge amp. I’ve had this endless time with all sorts of equipment. A part that costs pennies trashes a valuable piece of equipment. Anyway, that aspect adds to the personal satisfaction when the job is done. Thanks again for a great video.
It's the same model they have in my local cathedral church. They use it to drive three giant speakers pre-channel. It's a beast.
Thanks, Tony. I clicked on the video the moment I saw the word Peavey and 1200.
Those peaveas of that era are total BRUTES! you could put a dead short between each channel and it'll just go into protect while there's a short! I've seen people drive speakers of all ohm loads, wattages,etc.. and that amp will take it all.
I used to do guitar and amp repair in the late 90s. Peavey didn't make the best sounding gear, but it was good enough. The upside is that they durable as hell. The only problem I've ever had with 70s through 90s gear were cold solder joints or blown speakers. Brings back a lot of good memories seeing this.
The CS1200 and 1200X are one of my few favorite peavey products. They’re great amplifiers and they sound great if you modify the pre driver stage a bit. They sound a little flat stock.
Same thing with that same era of the CS800. Great affordable amps.
The best i have ever seen .Analysis/diagnosis was absolutely superb. Thank you very much.
I am jealous. I payed 90 buck for a cs 400, and rebuilt it. what a beast. you have a really big beast. one interesting thing about these amps is the speaker damping factor, meaning when the amp sends a signal, it does not allow the speaker cone to continue movement after the signal event. rater interesting to watch.
Oh trust me Tony, I'd gladly put an amp like that in my living room.
Excellent video, as always And Kim learning with every video I watch.
Incredible repair.... gotta give props to amps that are 2 ohm stable.... that's why I like my Crowns. I'm not loading them at 2 ohms, but it's nice to know I could... !
I also have crown amps and I loaned them at 2 ohms all of them
I used to run 12 big racks of these back in the day.. that was pretty much the stock fault.. the fan control circuit failed.. they went bang due to heat.. which is why you often see them with small strips of paper stuck in front of the grills on the front in pictures of big rack mount systems running these. Otherwise they were great amps... but damn heavy when you have 8 of them per rack !!!! (make sure to buy the venue lifting crew some beers if you like your gear in one piece after the show)
I love the old Peavey amps I have a PV 1.3 k rebuilt the whole thing all new resistors transistors diodes caps filters all the way down the line it took me about a month to rebuild Plus also waiting on parts. when you order parts from PV you have to look at the schematic and give them each part number it's crazy.😂 Got to know all the people at PV pretty well. Grant Brown said to me why are you rebuilding this amp when you can buy a new one with a lot more watts and I said because you can't beat the old PV amps they're built like tanks.😁 The PV 1.3 k weighs 100 lb and it has one huge transformer in it to run both channels LOL. 2,110 watts at 2 ohm load it's a powerhouse. I have a lot of time and money in it and I'm not getting rid of it for nothing 😂 if I was you I would keep that amp and never get rid of it. Brand new when the PV 1.3 k first came out the price tag was $5,000.
When I had a CS series in the shop with a problem on the amp board, it was common practice to replace all the diodes on the board. Diodes are cheap, and they were a high failure part in those.
Peavey is a victim of their own success when it comes to these old CS series amps. A lot of pro sound people are snobs and say "Peavey is junk". But what they are talking about are amps that are close to 40 years old in some cases and have never been serviced.
Yes was thinking the same. The old Peavey amps are known to be really good and reliable... but yeah there is always a lot of uneducated opinions in the audio field, especially in the "pro" and "high end" world lol
I've serviced a lot of Peavey over the years. Wasn't always the best sounding gear. However the reliability was good and mechanical design was solid. Their customer service was always fantastic too.
Hmmm... I don’t know about that. I’ve seen a repair video recently that got me absolutely appalled, where *a freaking burnt LED* took out the whole unit. It was from the IPR series, if I remember correctly.
P.S.: yep! Here you go: th-cam.com/video/HCrcbHSnogc/w-d-xo.html . It’s simply unbelievable!
I disagree. I've serviced a few of these amps and the design is one of the worst. They also sound bad, the pros are right, Peaveys really are junk.
What I love about electronics is that if there's something wrong with it it's usually a really simple and cheap fix. Most things that end up not working are due to electrolytic caps drying out.
Damn! wish you did this video about 15 years ago LOL. May have saved me about £200 on a repair bill when my CS1000X blew, Awesome and very interesting video thanks for sharing.
Tony you are a frickin genius, i watched this whole video and 11 of your other videos, i really enjoy the explanation, the way you run through everything and refer to the schematic, very educational, you are the best, no one i know explains things like you and it is fairly easy to understand, thank you., this was fun to watch,..
I wanna buy that amplifier
20:57 Beeeeeauty! These are real bobby dazzlers. These kinds of bridge rectifiers almost never fail.
I just watch your video and it was outstanding the way you took it step by step . Great job
What a great tutorial on using a Dim Bulb Tester. Just what I needed. I just cautioned my family and friends on the dangers of AC (even in small SMPSs) and the need for a DB Tester. Thanks! From the look of the grunge inside, I would think that amp had been used as the house amp in a bar. I would also think that it smelled pretty bad. I ran pro sound in the late 70's through the 80's. We had a good bit of Peavy equipment. It was cheap enough, but it all had really harsh high ends. We changed brands, as the company grew. I also had an electric guitar amp head and 4- speaker box. It was solid-state and 60 amps, IIRC. Inside the head, there was a funny little quality sticker that said something like "Made by beautiful virgins, in Meridian Mississippi. No kidding. Maybe someone knows the exact quote. It would be fun to know exactly.
These Peaveys were workhorses for their market. Before we upgraded to Crown we used a few of these and never had any issues.
as we used to joke in the 80's, "Peavey, the brand that ends in why". I will admit they are built like tanks and have only improved over time.
I have two CS-900s. Going to take both of them apart and replace the power transistors. One has an issue where one channel clips all the time with only a little input. The other amp sound distorted all the time. So, I'll try that and see what that gets me. Great video!
Good job saving the old iron :) And great explanation of the troubleshooting methods and what you can "see" by just using the dim bulb.. i love it, its my favorite and first-to-go tool for troubleshooting almost everything..
any time you even THINK a Peavey has failed to DC on the outputs.... Replace that SAC187 at the output. They are decent amps, rock it. Repaired hundreds of that era CS series.
Appreciate your video alot it helped me with my repair to my cs1200 , I'm a big fan of peavey most of my gear is peavey and they work real great.Thanks 👍
I really enjoyed watching this and you sure got a good deal for $20+diode!
Nice find and good troubleshooting skills.
Excellent troubleshooting skills Tony! Thanks man.
Awesome!! I am a tech as-well. Been using Peavey products for ever as a musician, great tutorial. Thanks!!
I used those a lot back in the
80s/90s there's a law, similar to ohms law that applies to those amps.
The CS series cost roughly $800 for an 800 watt and weighed seemed like 800lbs.
You almost couldn't stop them though.
Nice vid. I remember using those amps back in the day at a dance club. We had the CS1200X powering 4 JBL MR15's (2 per ch so at 4 ohms per ch). and then had 4 Silver CS600's bridged powering 4 JBL TR215's. (yes we blew the horns in the TR series several times but woofers were just fine). LOL Then a QSC RMX1500 pounding 3 8ohm 18inch Peavey Scorpion subs. Granted this was in 2001, owner was to cheap to buy decent speakers. LOL But that amp rack was built like a freaking tank. Weighed as much as one to cause I carried those bad boys up two flights of stairs. 1 at a time, 10 min break in between!!!
I repaired a small peavey guitar amp years ago, and inside the power transformer was a heat sensitive fusible link, interwound with the primary winding. In theory a reasonable protection idea but it threw me a curved ball thinking that the transformer itself was open. Shorted that and got the amp working. A real trap for young players!
Thanks for demonstrating troubleshooting with basically a dim bulb tester.
Fan mail.......LOL!!! Ok, I commented on this before saying I hate you cuz you got it for $20. The friggin KNOBS are worth the price!!! That aside I want to say I've been through MANY of these and own at least a half dozen-both reg. and X versions. Stellar amps btw. Mine all worked when I got them, but much of your troubleshooting could have been averted when you 1st took it apart to clean. These amps are old enough now they're quite dirty, so known history or not the 1st thing I do is tear em down to clean, and OHM EVERYTHING OUT--paying particular attn to all power devices-including those diodes. If you'd have done this you would have caught the diode and saved yourself a bunch of time. I read in the comments those are a high failure part-even though I've never seen it. Still an excellent practice to check them when tearing down/cleaning. On a diff note I'm glad you checked those caps for the lower voltage supply. While I'm aware of the hot running low speed fan resistor I wasn't aware of it cooking the snot out of that neighboring cap. Now I'll have to check all of mine.....smh. I loved your using a 50 watt resistor, as well as explaining how the fan switching speed circuit works. X versions claim to be 2 ohm stereo stable-I'd never run one that way for extended periods.....period. Love to see you tackle a peavey 1.3K as those, are a nightmare..... :)
Hi I hav pv cs 1200 vintage amp . I'm looking for top module board
Can sum one help me get this. I'm frm Durban s.a
EXCELLENT Video! You really understand your stuff! I am sure you would make an Excellent Electronics Teacher. I took several Basic Electronics Courses back in the 70's and worked on Radio and TV's for a short while. I still stay a little involved with electronics in the " Ham Radio" end of things. Looking back I I wish I had learned the theory and practice of electronic from more learned people, if you have instructors that are not sure of what exactly is going on in a given circuit, the student also is not going to end up being certain either. This is the first Video of yours I have watched and I will be looking for others now. Again, Excellent video in all regards. Thank You!
I found Tony's channel because I needed info on how to service my Pioneer SA7500, I've been hooked ever since.
Even started to watch from the first video he put up and learning lots.
Back when I used to work on peavey equipment, they give you the schematics and service information if you ask for it.
Fantastic video! Very good troubleshooting techniques. Simple. Effective. Subscribed!
The reason you didn't get a bright bulb with the power amp separated from the preamp is because you opened the feedback circuit. The shorted diode pulled the speaker line all the way to the power rail, but without the feedback there was nothing to turn on the opposite bank and cause a short across the power supply. (Also, no load on the amp, so, no place for the shorted power rail to go.)
That's cool and everything you fix that amp really good! I have a suggestion you go through all that trouble shooting and showing everybody how you fixed it and you don't bother to show buddy speakers hooked up to it.
Fix a lot of peavey gear here in centra fla. this one was a heavy Beast! Mine had several dead outputs on one channel good video!
Fantastic ! I happen to be using one of these and a 1000. Love them! I also have 2 of the DECCA 528's that are in serious need of repair, a DECCA 724 still in service ... WOW!!! What an amp. Also sub to your channel... I still push my luck on repairing these steel tanks also. Thanks...
The DECA series was one of the first amps to use a PWM switching power supply. Now most amps made use that topology. The DECA amps came out in the 1980s. Way ahead for their time. Digital Energy Conversion amplifer.
Why not hook it to the speakers to see what it sounds like? It looked like you checked for DC on the outputs etc. so it probably sounds fine and works fine.
I picked up a CS-2400 Amp from a friend who does storage lockers he was going to put in dumpster, but he gave it to me. I brought it back to life (bad safety relay) and I use it i my home system ,I got Cerwin vegas D9 on it and they sound great .
Thank you very much That was some very helpful information there i repair one of those back in Jamaica about three years ago the problem was with four of the output transistors.
Thanks Tony, good work. You really help me think in about the process in a useful way. Cheers. M
Picked up at a flea market ? My kind of challenge ! Well at least it was ten years ago .:(
Realy love your troubleshooting vids, thanks a lot for sharing, always interesting to see how other tecs solve problems :-)
I am really happy to see your equipments and way you work perfectly with the diagram and explaining about the corns and prons of it and rectify the faults skillfully with all the details do you repair music systems like GR-7(Sony)?
Nice informative video, Tony, Thank You!!
Thanks again for the continued education keep up the good work keep the videos coming
Great video, I really enjoyed it and learned a few things. Thanks a lot.
Very Cool, great repair video. Please play some music through your audio equipment. Thanks.
the Peavey stuff is pretty rugged, the Spec's aren't great tho
this may seem somewhat incongruous, but
I run a Crown K2 @ 500wpc/8ohms
into Klipschorns that need 3 watts .. :)
I run qsc and put my crowns in the work shop never hooked my horns to a peavey
I love the K2. Beautifully built with good parts and no fan!
Wow I wish I could have this amp good work bro God bless
It is an extremely well built amp with TO-3 metal transistors made by Motorola
Excellent video Tony! Have subscribed and going to watch them all, thank you!
lol...we used to use dead cs800's as wheel chocks to keep the box truck from rolling away...
You should have used yourself for the wheel chock and saved the cs800 it had all the talent
Just came across your channel and subscribed. Very informative indeed.
I had a CS400 and the output transistors were gone, shorted...I did not fix it...I scraped it..and took all the good transistors and various things..and you are right it had one single massive transformer..
Excelent video as usual I cant wait to see the next one
Great as always Tony
great video..great instructor,(although first 10 minutes seemed to be waist...you proved a short so how would the triac ckt going thru thermo switches cause that???maybe no primary voltage but not a short...anyway from then on excellent..im trying to repair a peavey -2600 and a gps 3500..., 2 questions..will a cap that is failing esr also test bad with cap test found on most dvm,s? can you talk about peaveys ddt circuitry, because I have a ddt light always on and cant see the ckt labled in the schematic?i know it haS SOMETING TO DO WITH COMPRESSION AND LIMITING INPUT..BUT HOW DOES IT SENCE?
I think that amp is made for professional high-end commercial uses such as DJs, Karaoke Bars, Hotel Ballrooms, Nightclubs, Public Address Systems, Conventions, Rock Concerts, School Auditoriums, Performing Arts Theaters, Stages, Studios, Fairs, Bands, and similar applications. That unit was not made for home stereo use.
Stephen Hinkle that doesn’t stop me from using a bogen m600 to power the subwoofers in my home stereo. Which is designed for the same purposes these are. They aren’t designed for it, but boy do they do a good job of it. Just at the expense of lots of energy usage. Mine needs a dedicated 20 amp circuit
They are made for whoever has the balls to hook up and the power supply
I used these often doing sound years ago before Class D amps took over. If you ever run across any Crown Macro Techs to work on they are really interesting.
Thank you, you just help me in how to fix mine
That thing is a work of art but what a pain to get to the nitty gritty is a good job you had the diagram
Peavey are pretty good if you contact them asking for schematics & service info. I emailed them for info on a bass amp, sent me the schematics with the proviso I didn't re-publish them etc.....DA
Yeah when I rebuilt my PV 1.3 k. Peavey sent me all the schematics so I could order all the parts.When you order parts you have to order by the part number on the schematic. You can't just tell them what part you need 😂
Thanks....great job....i like this video very much ...very clear 👍👍👍
Nice work! Thanks Tony.
Interesting. So the short only presents itself when you connect both rails simultaneously on the FULL BRIDGE RECTIFIER!!!
very good informative video, thank you.
Excellent explaining and work !
Would a capacitive dropper be a better (less heat) way to power the cooling fan, or would that, somehow, be dangerous? Thoughts/suggestions? I thought the OEM resistor was poor engineering, at best, and, maybe, a little nuts... Your resistor solution was much better than the original and looks like it will work well and be safe.
Tony. Did you ever think of troubleshooting one channel at a time by pulling the wire off the breaker. Just a thought for future troubleshooting as it would be fast
hold on hold on .... i would put that in my living room ......
It's a push pull amplifier, so when the negative or the positive is disconnected the short cannot be reproduced.
I really enjoyed this vid..... Thanks.
How is it so quiet? Fan speed wise..
I have a Peavey CS 1000, and the fan is ridiculously loud! Always runs flat out speed, and can clearly hear it over the audio, when at comfortable levels in a room
Ich liebe deine großartige Arbeit. Wieder mal direkt das Problem gelöst. Unglaublich !!! ( Wie groß muß ein Schaltplan sein, um Dich mal herauszufordern?! ) glg.
Nice repair.
This stereo mon0 block amp goes up to 11 ! Will post this video on EEVblog forum 10/31/2018
Can you tell me or recommend, where to buy this peavey cs3000 Circuit Board, because it just burn. I can see the model was P2500AMP on the board. Thanks
i'm from mumbai-india. had made 50+50 rms using 3055/2955, 25 years back in my electronics diploma, probably had the highest o/p compared to 3-10w ready made pieces, really loved the fully analog sound response, now using a 50*2+100w aliexpress class d, with optical/coax .
3/4 valume settings should put the led lights at yellow turn the nob more /red comes still not peeking the 1 red top red light turns on when u drive the amp going for 2400watts
dont think theymade many of those 1200 x but i have one in my rack i replaced 1 power suply cap shes back up and runing fine
What do you mean it would not be for home use because thats exactly what I would use it for. I got a 1500 watt Crest Audio pro amp in my front room.
Nice job, and thanks for sharing
I'm a new fan!
As soon as we saw the schematic, it occurred to me that if you have two identical channels,
you should have been able to isolate bad channel much more quickly.
Cool stuff, thanks for the informative video! I have a question though. Moving the power resistor from the board to a more remote location is certainly a good idea but are you sure these tiny yellow wires can take the load? (beginning @35:12)
Go back and you will see and hear that those wires carry the current of the fan. @37:52 you will see that the Maximum current draw of the fan is 0.28 amp which just about any wire will handle.
Very nice video! But i wonder why this power resistor got so hot if it is shorted after the amp is on. Did you check the opto insulator and the triac ? If they don't work the resistor would not be shorted, it would get hot, the fan would not get full power, and maybe cause thermal damage to the power transistors.
Great question! The purpose of the resistor is to limit the power to the fan to make it run slower. This quiets it down, so you don't hear the loud fan at lower volumes. If the amp begins to overheat at higher volumes, the thermal switch will close and cause the TRIAC to gate on, shorting out the resistor and applying full power to the fan (which will then be very noisy). In most cases, the fan will run at low speed through the resistor. When Peavey designed the amp, they used a power resistor that gets very hot, due to the amount of power it has to dissipate. To make matters worse, they mounted it on a PC board right next to the power supply capacitors. Going to a larger resistor and moving it off of the board allowed everything to run much cooler. The same problem exists on the Soundcraftsmen amp I restored (check out the video) . Hope this helps to explain things. Thanks for watching!
yeah , and with no load this amp sits there and runs the fan in slow mode but power resistor is working overtime....(kinda of a stupid circuit)..and who knows amp was probably left on long periods of time perhaps days and weeks at a time, waiting for signal.
Great video👍👍
Very good.
I have one I need to look at. These go through a self check on startup. If it self checks ok a relay for each channel can audibly be heard activating. I'm only hearing one on mine, hence only half is working. Where are those relays located in these units?
GREAT INFOMATION...
Hi there, I am servicing an old Krell Power Amplifier with a push pull circuit.
It consists of 14x NPN plus 14x PNP transistors.
What puzzled me was that the PNP ones had an average hfe (Beta) of around 45 whereby the NPN side measures around 115.
My first question: Shouldnt the push and the pull side be matched to have both the same level of amplification or is that somehow taken care by the driver setup?
Secondly: the amplification range on the PNP as well as on the NPN side various greatly( 16-67 NPN, 105-168 PNP side) is that caused by aging ? Could i still leave it or would it be risky to operate the amp under such condition? I believe it will cause an uneven distribution of load but under normal load that might not be too bad ?
man your brilliant, do you have a shop ? I have a electronics degree and I am scared of my cs1200x.