If I get another pro amp...its gonna be one of the later units with the complementary OPS. (The CS800X)
So off topic a bit...what pro amps are regarded for sound quality? What's the modern equivalent of the CS800 durability wise? (or is there such a beast?)
You will get a bunch of different answers there.
Personally I like Crown- the MA and MT amps have always been good to me. The old Crest Pro amps (7001,8001,etc) were pretty tough and sound great, but are getting very long in the tooth. I like the newer QSC switching amps and of course- LabGruppen. We use a ton of those at work.
Personally I like Crown- the MA and MT amps have always been good to me. The old Crest Pro amps (7001,8001,etc) were pretty tough and sound great, but are getting very long in the tooth. I like the newer QSC switching amps and of course- LabGruppen. We use a ton of those at work.
The CS800S is selling at a discount probably because of the heavy transformer power supply and binder post output instead of speakon terminals. Both are not wanted by bands that have to tote everything out of the truck and hook it up before the gig. The CS800S sounds great at room volumes. It sounds better than my Dynaco ST70, one of the legends of the fifties. I auditioned a 600W peavey amp at the store last summer, sounded fine, but it was $999. The newer models have switcher power supplies, a lot lighter and probably less fan run, too. At room volumes, I never hear the fan run on my CS800S. Speakon terminals are too expensive for the home user, but have real reliability advantages for frequent hookup and teardown. My local proshop only sells peavey, although they do have some powered mixers in other brands. The powered mixer integrates the mixer with a 200-300W amp, and probably would be fine for home use.
I came across this thread today while "glancing around" the forums.
I have had two CS800's fixed in the last 10 yrs and never had the opportunity to hear them as they were from friends of mine who had me relay them to my tech for repairs.
I enjoyed the thread and all the info and expertise that was shared!
Regards, Ron
"tube and horn guy"
I have had two CS800's fixed in the last 10 yrs and never had the opportunity to hear them as they were from friends of mine who had me relay them to my tech for repairs.
I enjoyed the thread and all the info and expertise that was shared!
Regards, Ron
"tube and horn guy"
you still have those 2 amps still sitting their doing noting ? ...might be
interested in buying dem ? ..
Zero Cool
jeeez how many of them do you want? people here have started using them as Semi truck Wheel Chocks! LOL! I see them in various states of working and non working and I have even sold many in the $50 to $150 price range! I think there is 2 sitting in the scrap pile now.
you still have those amps i might buy it from you ! ....
jeeez how many of them do you want? people here have started using them as Semi truck Wheel Chocks! LOL! I see them in various states of working and non working and I have even sold many in the $50 to $150 price range! I think there is 2 sitting in the scrap pile now.
you still have those amps i might buy it from you ! ....
jackintnt, update your profile to at least show your state on your posts. There were 3 early SP800's on indianapolis craigslist about 2 weeks ago, the seller said they were in michigan. He wanted $500 for the three.
"The CS800S is selling at a discount probably because of the heavy transformer power supply and binder post output instead of speakon terminals."
Actually the CS800S - S for Switcher - has a switching powr supply, and no heavy power transformer. The whole amp weighs less than 23 pounds. The S version did come with the P1 output module, that is the output connection module with 1/4" jacks and banana binder posts. But you can swap that for an S1 or S2 module which has the Speakons.
Actually the CS800S - S for Switcher - has a switching powr supply, and no heavy power transformer. The whole amp weighs less than 23 pounds. The S version did come with the P1 output module, that is the output connection module with 1/4" jacks and banana binder posts. But you can swap that for an S1 or S2 module which has the Speakons.
I am a self taught, learning tech. I started with tube amps but have had many solid state power amps come into my shop and due to the economy, I have no choice but to take them on. Everyone has been a learning experience. I am currently working on an older CS 800. It's an A or a B. Not sure which. Both channels are passing signal but I have a loud hum in channel B that is not effected by the volume knob. Sounds like a cap or a bad component to ground somewhere after the input board to me but I haven't found it yet. Still looking. There is one mod that I've noticed that has me a bit puzzled. There is a 1N4148 diode soldered in series on the 25volt 100uF cap on the driver board. Any suggestions or opinions would be greatly appreciated.
Thanks in advance
Thanks in advance
Do you need schematics? Do the level controls have push-pull switches for compression defeat? This will narrow down the model you have.
Craig
Craig
I do have schematics for all three.
They are not push pull volume knobs.
I've worked on a C before that had them.
By looking at the driver board schematic and components, I think what I have here is a B. I've gone through all components on the driver board and everything seems to check out good. I've checked the output transistors without pulling them and they seem to check out good. Now it is missing acc. jumper plug on the humming side. I tried plugging in the one from channel one but it makes no difference. Wondering if I should just start checking voltages or just go ahead and pull apart the output board and check the rest of the components in there?
Any suggestions as to what the check next? Every power amp I've worked on has been a new learning experience.
Thanks again, David
They are not push pull volume knobs.
I've worked on a C before that had them.
By looking at the driver board schematic and components, I think what I have here is a B. I've gone through all components on the driver board and everything seems to check out good. I've checked the output transistors without pulling them and they seem to check out good. Now it is missing acc. jumper plug on the humming side. I tried plugging in the one from channel one but it makes no difference. Wondering if I should just start checking voltages or just go ahead and pull apart the output board and check the rest of the components in there?
Any suggestions as to what the check next? Every power amp I've worked on has been a new learning experience.
Thanks again, David
If you are more comfortable with tubes, think a second. Would you look at a tube amp and start pulling all the parts and testing them? What if it was a tube socket pin not making good contact? Not everything is a bad part. COnnections are important too.
First identify the problem. A loud hum? I doubt the jumper plug matters, but you have a good channel, pull its plug. Does that side start humming? I bet not.
Does it hum with nothing plugged into any of the inputs? Or only when a signal cord is connected? And does the volume control affect the hum at all?
What exactly is on that bad output? is there any DC offset? use a scope. and check the power rails, both for the power stages and for the op amps - anyone full of ripple instead of smooth?
The A and B versions have a single IC on the driver board, and that is a single op amp. A TL071 or equivalent. SO make sure a dual op amp was not instaled in its place. Check it for voltages. Pins 4 and 7 are its power pins, each with 16v supplied right on the card. Are both polarity supplies up to about the same voltage and smooth DC? And output is pin 6, is ther any DC offset?
The two driver cards are the same, you can swap them to see if the problem stays or travels with the card.
Scope the output, any RF riding the output? AMps oscillating at RF will often sound weak and hummy at audio.
First identify the problem. A loud hum? I doubt the jumper plug matters, but you have a good channel, pull its plug. Does that side start humming? I bet not.
Does it hum with nothing plugged into any of the inputs? Or only when a signal cord is connected? And does the volume control affect the hum at all?
What exactly is on that bad output? is there any DC offset? use a scope. and check the power rails, both for the power stages and for the op amps - anyone full of ripple instead of smooth?
The A and B versions have a single IC on the driver board, and that is a single op amp. A TL071 or equivalent. SO make sure a dual op amp was not instaled in its place. Check it for voltages. Pins 4 and 7 are its power pins, each with 16v supplied right on the card. Are both polarity supplies up to about the same voltage and smooth DC? And output is pin 6, is ther any DC offset?
The two driver cards are the same, you can swap them to see if the problem stays or travels with the card.
Scope the output, any RF riding the output? AMps oscillating at RF will often sound weak and hummy at audio.
are the filter caps any good? are the bridge rectifiers good? are both halves of the triac good etc
Quote: First identify the problem. A loud hum? I doubt the jumper plug matters, but you have a good channel, pull its plug. Does that side start humming? I bet not.
You are right. Does not matter
Quote: Does it hum with nothing plugged into any of the inputs? Or only when a signal cord is connected? And does the volume control affect the hum at all?
There hum weather a cord is plugged in or not and volume control does not effect it which led me to believe it was somewhere in the output.
What exactly is on that bad output? is there any DC offset? use a scope. and check the power rails, both for the power stages and for the op amps - anyone full of ripple instead of smooth?
Unfortunately I don't have a scope up the to job. Both my scopes are old tube scopes that need to be rebuilt. A modern one is on my list. But I do have a nice desktop meter.
Quote;The A and B versions have a single IC on the driver board, and that is a single op amp. A TL071 or equivalent. SO make sure a dual op amp was not instaled in its place. Check it for voltages. Pins 4 and 7 are its power pins, each with 16v supplied right on the card. Are both polarity supplies up to about the same voltage and smooth DC? And output is pin 6, is ther any DC offset?
Both op amps are identical with same numbers. I will check the voltages next with my meter.
Quote: The two driver cards are the same, you can swap them to see if the problem stays or travels with the card.
I did a bunch of swapping. I first changed the whole output stage from on side to the other. The Hum did end up on the other side. Then I changed the driver card from one side to the other. The hum changed sided again leaving me to believe that I missed something in the driver card. Then for the heck of it, I tried switching the op amps from one side to the other. I don't get as much hum, but now I get it from both sides. Strange.
Now if it was a filter cap or something in the power supply, wouldn't I have the same problems on both sides?
You are right. Does not matter
Quote: Does it hum with nothing plugged into any of the inputs? Or only when a signal cord is connected? And does the volume control affect the hum at all?
There hum weather a cord is plugged in or not and volume control does not effect it which led me to believe it was somewhere in the output.
What exactly is on that bad output? is there any DC offset? use a scope. and check the power rails, both for the power stages and for the op amps - anyone full of ripple instead of smooth?
Unfortunately I don't have a scope up the to job. Both my scopes are old tube scopes that need to be rebuilt. A modern one is on my list. But I do have a nice desktop meter.
Quote;The A and B versions have a single IC on the driver board, and that is a single op amp. A TL071 or equivalent. SO make sure a dual op amp was not instaled in its place. Check it for voltages. Pins 4 and 7 are its power pins, each with 16v supplied right on the card. Are both polarity supplies up to about the same voltage and smooth DC? And output is pin 6, is ther any DC offset?
Both op amps are identical with same numbers. I will check the voltages next with my meter.
Quote: The two driver cards are the same, you can swap them to see if the problem stays or travels with the card.
I did a bunch of swapping. I first changed the whole output stage from on side to the other. The Hum did end up on the other side. Then I changed the driver card from one side to the other. The hum changed sided again leaving me to believe that I missed something in the driver card. Then for the heck of it, I tried switching the op amps from one side to the other. I don't get as much hum, but now I get it from both sides. Strange.
Now if it was a filter cap or something in the power supply, wouldn't I have the same problems on both sides?
There is one common power supply to both channels - power related issues should affect both sides equally.
You may not have a scope, but your meter can tell you if the output has DC on it or not.
Those IC voltages are important and will tell us a lot.
You may not have a scope, but your meter can tell you if the output has DC on it or not.
Those IC voltages are important and will tell us a lot.
hi fellows got a real tuff 1 for u got a peavey cs800s what is not working the problem is that a first tech was trying to repair the amp and shorted the positive rail to chassis now there is no output from both channels check powersupply is ok yet no output transistors damaged can't find any bad parts on the driver board check all connection for open they are some voltage that r not reading as they should on the schematics help as i am in jamaica an oringinal parts r hard to get can any 1 help
CS800 on off switch
Hi, I have a very old CS800 without the DDT compression, just overload lights. I use it for Pro Band use and it works fine, we limit the input with a compressor so as to not overdrive the amp.
Anyway, a couple of years ago I went to shut it off, but it kept running, including the fan. I tried it when it was hot and cold and it just stayed on regardless of the the power switch.
I ordered and received a new power switch from Peavey and installed it and there is no difference. With the switch off when I plugged in the amp, the amp didn't run, then I switched on the power and after that it just stays on no matter what position the on/off switch is on. To turn it off, I have to unplug it. I am not an electronics guru by any means, but I can replace and test components.
I should probably just get a more modern amp instead of lugging this one around, but I hate it when something is broken
but still works, just harder to use. It's annoying to have to unplug the amp after practice or at a gig.
Any ideas? Like I said, I replaced the power switch.
Thanks,
Tracy
Hi, I have a very old CS800 without the DDT compression, just overload lights. I use it for Pro Band use and it works fine, we limit the input with a compressor so as to not overdrive the amp.
Anyway, a couple of years ago I went to shut it off, but it kept running, including the fan. I tried it when it was hot and cold and it just stayed on regardless of the the power switch.
I ordered and received a new power switch from Peavey and installed it and there is no difference. With the switch off when I plugged in the amp, the amp didn't run, then I switched on the power and after that it just stays on no matter what position the on/off switch is on. To turn it off, I have to unplug it. I am not an electronics guru by any means, but I can replace and test components.
I should probably just get a more modern amp instead of lugging this one around, but I hate it when something is broken
but still works, just harder to use. It's annoying to have to unplug the amp after practice or at a gig.
Any ideas? Like I said, I replaced the power switch.
Thanks,
Tracy
A switching power strip is great for shutting down the whole PA. or just the amp. Usually a rack has 1 power supply outlet. Handy as hell....
Look for a Triac or back to back SCR's that won't shut off. These amps have such an inrush current that I think they do the actual switching with triacs, not the actual switch. The snubber might be bad, also. (capacitor-resistor network to cut the slope of the change of the input voltage). The schematics floating around on the internet don't seem to show this power stuff. I'm buying 400 v 16A triacs in TO220 package for about $.75 each. But there is some kind of mysterious 3 spade lug device screwed to the bottom of my Peavey amp (not the CS800s) that I'm guessing is a SS (solid state) relay/heat sink that is not generally available except from Peavey. An actual SS relay from Crydom is much bigger and about $30.An SS relay is a triac, the snubber network, the trigger device, an opto isolator, and a zero crossing detection device to eliminate pop when the triac turns on or off: plus big screw terminals for the wires, and a heat sink plate on the bottom.
Last edited: