Conrad, any tool is only as useful as the knowledge of its use possed by the guy using it. I haven't used a bulb limiter in decades, I use a variac and ammeter. If you have been servicing solid state amps for 38 years, I have to believe you have some way to apply partial powr to a circuit. I can't imagine you replace a bunch of parts in a blown amp and then just flip it on.
A variac is expensive, and not everyone starting out can aford one. The bulb limiter is something someone can make for a couple dollars. IN fact a couple clip leads and a table lamp from the bedroom table and you have one for free. Is it ideal? NO. Are there more effective alternatives for professionals? Sure. But it can be an effective tool in troubleshooting amps.
The bulb limiter only causes problems when you don't really understand its context and proper application. The variac I swear by is the same way, really. I see peoploe writing in that they used a variac, then go on to report that they get the amp to "work OK" up to 80 volts then resistors start to burn and by 95 volts all the output transistors blew. Well, duh, once we start seeing current ramp up we back off, not continue to go and see what happens. That person didn't understand the use of a variac. Not the fault of the variac. I really hope you don;t think variacs are useless too.
A variac is expensive, and not everyone starting out can aford one. The bulb limiter is something someone can make for a couple dollars. IN fact a couple clip leads and a table lamp from the bedroom table and you have one for free. Is it ideal? NO. Are there more effective alternatives for professionals? Sure. But it can be an effective tool in troubleshooting amps.
The bulb limiter only causes problems when you don't really understand its context and proper application. The variac I swear by is the same way, really. I see peoploe writing in that they used a variac, then go on to report that they get the amp to "work OK" up to 80 volts then resistors start to burn and by 95 volts all the output transistors blew. Well, duh, once we start seeing current ramp up we back off, not continue to go and see what happens. That person didn't understand the use of a variac. Not the fault of the variac. I really hope you don;t think variacs are useless too.
Back to the CS800. The two ICs on the driver board are op amps. One is a single op amp. That is an 8-pin part with one op amp circuit in it. The other is a dual op amp. Same package (part shape) but with two independent op amps inside. They are labeled on your drawing, 4558 and 5534. They are both common industry types. 4558s are still around, though these days there would be a 4580 there instead. Mouser or similar should have them all anyway. There will be a couple letters ahead of that like NE5534 or RC4558. Different brands use different letters. The letters after the number represent the package. These are DIP (dual inline package) for "throughole" mounting. You want the ICs in DIP or DIP8 or similar. All these parts also come in tiny surface mount. The last letteres will determine that, so be careful shopping. You won't want SOIC for example. (small outline integrated circuit)
What is an op amp? is too broad a question for here. Just look it up. It is a circuit of relative complexity inside a simple package. It has gain. It had inputs and outputs and power connetions. It is used as a functional block in a circuit.
PV used several transistor types as finals in these. The schematic calls for 6451 or 6343 at top of the page. the amp has 10 outputs - five per polarity. There are 12 large transistors but the end ones on each row are drivers. PV wants all 10 to be the same. The amp is quasi, so all 10 are NPN. Those numbers may have SJ printed before the number - SJ6343. The SJ is understood if not. Those are house numbers. At some point PV changed the number system on house numbers. The SJ6451 and SJ6343 both became 70483180. So you may see those numbers on newer amps. Those are all Motorola (ON Semi) and are MJ15024. Most today will have a G suffix for lead free. I recommend that type.
PV also used RCA parts. SImilar specs but different process, so DO NOT MIX them ALL RCA or ALL MOTO. As far as I know PV never had SJ numbers on the RCAs. Those house numbers were 6xxxx. 66161 is specified on the B series drawings, and some of the C series like yours were no doubt made with them as well. 66161 is an RCA1B05. Other than sitting in someone's drawers, 66161 are not available, the PV part number for them is 70483180. Yes, if you order them now, they will send you the Moto parts. I don't care if you use Moto or RCA, but don;t mix them. You CAN mix SJ6343 and 70483180 since they are both MJ15024.
The drivers are 6387 on the print, but what are they on your machine? If they are not blown, then leave them. The cross is MJ13330 but anothe MJ15024 should work intheir place. PV type 70481180.
The 67068 drivers are RCA 1B09 if you have them.
You just are not going to find heftier transistors that MJ15024. Yes Moto has a newer equivalent people like, but don;t mix them. Thes amps don;t blow up because the transistors are under rated. Hartley Peavey has some interesting white papers you can read on their web site. Thos eamps are designed with twice the transistors in the output than most equivalent competing brands. They may not be the highest fi in hifi, but they are solid amps.
An output shorting will put DC rail on the output and blow fuses when loaded or crowbarred. But a dead driver or predriver can tell the outputs to PUT DC on the output and they will obediently do just that even though they themselves are OK parts.
Peavey publishes a semiconductor cross reference for their house numbers. It is currently a sticky over at Music-Electronics-forum in the schematic request section. Go there and retrieve a download. Or ask PV customer service for it.
May I respectfully say, quit worrying about the damned triacs.
What is an op amp? is too broad a question for here. Just look it up. It is a circuit of relative complexity inside a simple package. It has gain. It had inputs and outputs and power connetions. It is used as a functional block in a circuit.
PV used several transistor types as finals in these. The schematic calls for 6451 or 6343 at top of the page. the amp has 10 outputs - five per polarity. There are 12 large transistors but the end ones on each row are drivers. PV wants all 10 to be the same. The amp is quasi, so all 10 are NPN. Those numbers may have SJ printed before the number - SJ6343. The SJ is understood if not. Those are house numbers. At some point PV changed the number system on house numbers. The SJ6451 and SJ6343 both became 70483180. So you may see those numbers on newer amps. Those are all Motorola (ON Semi) and are MJ15024. Most today will have a G suffix for lead free. I recommend that type.
PV also used RCA parts. SImilar specs but different process, so DO NOT MIX them ALL RCA or ALL MOTO. As far as I know PV never had SJ numbers on the RCAs. Those house numbers were 6xxxx. 66161 is specified on the B series drawings, and some of the C series like yours were no doubt made with them as well. 66161 is an RCA1B05. Other than sitting in someone's drawers, 66161 are not available, the PV part number for them is 70483180. Yes, if you order them now, they will send you the Moto parts. I don't care if you use Moto or RCA, but don;t mix them. You CAN mix SJ6343 and 70483180 since they are both MJ15024.
The drivers are 6387 on the print, but what are they on your machine? If they are not blown, then leave them. The cross is MJ13330 but anothe MJ15024 should work intheir place. PV type 70481180.
The 67068 drivers are RCA 1B09 if you have them.
You just are not going to find heftier transistors that MJ15024. Yes Moto has a newer equivalent people like, but don;t mix them. Thes amps don;t blow up because the transistors are under rated. Hartley Peavey has some interesting white papers you can read on their web site. Thos eamps are designed with twice the transistors in the output than most equivalent competing brands. They may not be the highest fi in hifi, but they are solid amps.
An output shorting will put DC rail on the output and blow fuses when loaded or crowbarred. But a dead driver or predriver can tell the outputs to PUT DC on the output and they will obediently do just that even though they themselves are OK parts.
Peavey publishes a semiconductor cross reference for their house numbers. It is currently a sticky over at Music-Electronics-forum in the schematic request section. Go there and retrieve a download. Or ask PV customer service for it.
May I respectfully say, quit worrying about the damned triacs.
Somewhere in the RCA to Motorola transition they went from hometaxial to epitaxial process. Similar but NOT identical characteristics and NOT compatible in mixtures.
If the amp works but sounds noisy, especially at low volume, replace all the caps on the drive board and use modern op-amps. (the 5534 or 4558 should be adequate, the 1741/741s are inadequate for hi-fi use) A faulty opamp can also cause noise.
You have the amp with the DDT compressor. The amp mentioned in my thread lacks the compressor, hence the simpler schematic. Also, the series I CS800 did not have the triac switching circuit.
All CS-800 (not to be confused with CS-800X or CS800S!) use triac crowbar circuits to save the speakers from certain destruction in the event of a DC fault.
I wouldn't call it too crappy...yes, it's heavy as hell and bulky. No, it's not great in the THD department 20KHz (1% or so). It's 200W/ch (8 ohms) or 400W/ch (4 ohms) or 800W bridged into 8 ohms ALL NIGHT LONG for dirt cheap. (or unofficially, 1200W bridged into 4 ohms intermittent duty, great for subwoofers in home theater. The THD in the 20-100Hz region is low too.)
In short, I'm glad I fixed mine and I'm happy with it. The neighbors...well, that depends on if they're fans of my music. Please let my new apartment neighbors be rave kids.
If the amp works but sounds noisy, especially at low volume, replace all the caps on the drive board and use modern op-amps. (the 5534 or 4558 should be adequate, the 1741/741s are inadequate for hi-fi use) A faulty opamp can also cause noise.
You have the amp with the DDT compressor. The amp mentioned in my thread lacks the compressor, hence the simpler schematic. Also, the series I CS800 did not have the triac switching circuit.
All CS-800 (not to be confused with CS-800X or CS800S!) use triac crowbar circuits to save the speakers from certain destruction in the event of a DC fault.
I wouldn't call it too crappy...yes, it's heavy as hell and bulky. No, it's not great in the THD department 20KHz (1% or so). It's 200W/ch (8 ohms) or 400W/ch (4 ohms) or 800W bridged into 8 ohms ALL NIGHT LONG for dirt cheap. (or unofficially, 1200W bridged into 4 ohms intermittent duty, great for subwoofers in home theater. The THD in the 20-100Hz region is low too.)
In short, I'm glad I fixed mine and I'm happy with it. The neighbors...well, that depends on if they're fans of my music. Please let my new apartment neighbors be rave kids.
I think some people are looking for a constitutional amendment to define transistors as epitaxial. Hometaxial transistors are an abomination against nature.
You explained it better than I did. If you try to mix the types, they won;t share current or track thermally very well. The amp depends upon all the outputs sharing current and thermally tracking.
You explained it better than I did. If you try to mix the types, they won;t share current or track thermally very well. The amp depends upon all the outputs sharing current and thermally tracking.
Thanks for all the replies and useful information.
Say for what ever reason, the outputs had to be replaced. Do the MJ15024s need to be matched? Same question applies to the driver transistors. Also, if say one channel has a high DC offset (several hundred mV) is there a set of transistors that must be matched on the driver boards?
I noticed there is a diode that is held to the heat sink, and connects to the driver board via a cable. there is also a diode mounted in the same fashion on the diver board. Are these bias diodes? I assume the one on the heatsink is for thermal tracking? What diodes are these? a 1N____? I hear its actually two diodes in one casing, but I'm not sure.
Say for what ever reason, the outputs had to be replaced. Do the MJ15024s need to be matched? Same question applies to the driver transistors. Also, if say one channel has a high DC offset (several hundred mV) is there a set of transistors that must be matched on the driver boards?
I noticed there is a diode that is held to the heat sink, and connects to the driver board via a cable. there is also a diode mounted in the same fashion on the diver board. Are these bias diodes? I assume the one on the heatsink is for thermal tracking? What diodes are these? a 1N____? I hear its actually two diodes in one casing, but I'm not sure.
Drivers don;t have to be matched because they work alone. Nothing to match TO.
No, the outputs do not require matching. I buy the MJ15024 in bulk for my shop. It saves me a little on price, and they go in just about anything. Peavey doesn;t match them, they sell them loose, no grading marks. The ones in the amps are not graded. All those 10 watt 0.33 ohm resistors at the output transistors? That is what they are for, they keep the transistors evened out.
I don't know that I have ever seen one of these with an offset that needed correcting. And as I said before, I don;t consider 40 volts an "offset." I am sure we could correct it if it came up. Nothing in these amps is so touchy as to need balancing, matching, or polishing, or waxing, or a fresh coat of paint. They are in general stable and they settle down on their own.
Diodes? Look at your schematic. I don;t recall, do you have the complete schematics? That includes the board layouts? On the driver board layout you can see on top of Q9, it says CR11. That is one you mention. Find CR11 on the schematic. Center of driver card schematic, just left of Q7, Q8.. CR11, CR12. The symbol shows them as dual drop diodes - two diodes in series in one part. See the ** and * next to them? Now look down and to the right, above the main power supply and below the output triac. Two little lonesome memo notes:
**13886 attached to 6018
*13886 attached to HS
HS is heat sink. 6018 is Q9. The diode is a 13886 type, Peavey sells them. Yes, they are your bias diodes. Part number is 70413886. (704 is PV code for semiconductor) It is telling you where they are located. The dashed line around them on the schemo means they are not right on the pc board.
Some guys have cobbled other diodes into the circuit in place of them, but y'know, for a dollar or whatever they are, I get the exact thing, that drops right into the circuit and acts like it is supposed to. WHy screw around?
No, the outputs do not require matching. I buy the MJ15024 in bulk for my shop. It saves me a little on price, and they go in just about anything. Peavey doesn;t match them, they sell them loose, no grading marks. The ones in the amps are not graded. All those 10 watt 0.33 ohm resistors at the output transistors? That is what they are for, they keep the transistors evened out.
I don't know that I have ever seen one of these with an offset that needed correcting. And as I said before, I don;t consider 40 volts an "offset." I am sure we could correct it if it came up. Nothing in these amps is so touchy as to need balancing, matching, or polishing, or waxing, or a fresh coat of paint. They are in general stable and they settle down on their own.
Diodes? Look at your schematic. I don;t recall, do you have the complete schematics? That includes the board layouts? On the driver board layout you can see on top of Q9, it says CR11. That is one you mention. Find CR11 on the schematic. Center of driver card schematic, just left of Q7, Q8.. CR11, CR12. The symbol shows them as dual drop diodes - two diodes in series in one part. See the ** and * next to them? Now look down and to the right, above the main power supply and below the output triac. Two little lonesome memo notes:
**13886 attached to 6018
*13886 attached to HS
HS is heat sink. 6018 is Q9. The diode is a 13886 type, Peavey sells them. Yes, they are your bias diodes. Part number is 70413886. (704 is PV code for semiconductor) It is telling you where they are located. The dashed line around them on the schemo means they are not right on the pc board.
Some guys have cobbled other diodes into the circuit in place of them, but y'know, for a dollar or whatever they are, I get the exact thing, that drops right into the circuit and acts like it is supposed to. WHy screw around?
Enzo, yes I will admit to owning several Variacs. As important is that sense of when to back off rather than letting the smoke out of the parts. Even then, I don't do much power-on troubleshooting of solid state amps. It's just the nature of modern DC coupled designs to have cascade failures and mysterious interactions, so I avoid it. I do extensive checks of the components, mostly with a DVM, so that when I do apply power the chances of success are very high. In a similar thread by the OP elsewhere I mentioned some problems I had with a similar Peavey repair. Those diodes were bad in mine as well. I wish there were some magic quick troubleshooting recipe, but IMO it comes down to meticulously testing every known trouble point so the odds of a good power-up are in ones favor.
Okay. Now on to amp 1. Amp 1 is interesting. One channel is workin' the other is dead. I swapped the driver cards. The dead channel is now alive, and the alive channel is now dead. So yeah, the driver card is goofed. Here's the thing. Remember with amp 2, when I had a speaker and turned it on with a DBT, and I suspected a short, even though I was wrong? Well the channel that works fine in amp 1 doesn't show this issue. With a speaker connected, it dims down, and I don't have to attach a load once powered on.
But the DEAD channel behaves exactly like amp 2. That said, the outputs are fine, and the issue is the driver card. I didn't check for DC, but the speaker cone doesn't flap around. Its just dead. No hum, no hiss, no static, no music.
On amp 1, the bad driver board has the two op amps (all these amps have two op socketed op amps on each driver card. WHats the mouser part number for a replacement. One of the OP amps on the board had severly corroded leads, and when I removed it, a few leads remained in the socket. I'm not sure if it was dead before, but it certainly is now. I'll also need a new socket, because I can't get the remains out. If you have a DigiKey or Mouser part number for both op amps, and the sockets, that would be great.
That said, once I do have the part numbers, I do want to trouble shoot before I buy anything. I guess I'll just grab some op amps out of amp 3 to do the test.
What I might want to do is replace all the semiconductors on the driver card along with the capacitors. Caps age, and semiconductors can drift in value a bit, and a refresh can't hurt. I know on my Hafler, a lot of the transistors were out of spec, hence a 1V DC offset in one channel, and 430mV in the other.
So yeah, the driver card is goofed. Here's the thing. Remember with amp 2, when I had a speaker and turned it on with a DBT, and I suspected a short, even though I was wrong? Well the channel that works fine in amp 1 doesn't show this issue. With a speaker connected, it dims down, and I don't have to attach a load once powered on.But the DEAD channel behaves exactly like amp 2. That said, the outputs are fine, and the issue is the driver card. I didn't check for DC, but the speaker cone doesn't flap around. Its just dead. No hum, no hiss, no static, no music.
On amp 1, the bad driver board has the two op amps (all these amps have two op socketed op amps on each driver card. WHats the mouser part number for a replacement. One of the OP amps on the board had severly corroded leads, and when I removed it, a few leads remained in the socket. I'm not sure if it was dead before, but it certainly is now.
I'll also need a new socket, because I can't get the remains out. If you have a DigiKey or Mouser part number for both op amps, and the sockets, that would be great. That said, once I do have the part numbers, I do want to trouble shoot before I buy anything. I guess I'll just grab some op amps out of amp 3 to do the test.
What I might want to do is replace all the semiconductors on the driver card along with the capacitors. Caps age, and semiconductors can drift in value a bit, and a refresh can't hurt. I know on my Hafler, a lot of the transistors were out of spec, hence a 1V DC offset in one channel, and 430mV in the other.
Pick the dead channel, work on it, ignore the other channel until this is done. You have determined the channel works except for the driver card. SO the card is what we have to fix. You have a rotted IC and socket. The amp surely cannot function with that, so we need to replace it. Not much we can do until then.
The shape and size of the ICs here is called a DIP. Dual Inline Package. The sockets for them are called DIP sockets. If you see DIP8 instead of just DIP, that simply means an 8-pin DIP socket or IC. They come in other sizes too. PDIP means plastic DIP. That is OK too. SOme DIPs are ceramic, perhaps even yours. Any kind is OK.
The ICs are 4558 and 5534. There will be letters too, like RC4558 or BA4558. Each brand is different letters. But you need them in DIP.
Mouser is a good supplier, but don;t forget Peavey, they sell direct. Prices are not outrageous. You can call them up and ask for a "4558 IC" and a "5534 IC" and "8-pin IC sockets" and they will know. If you are going to order anything else from them already,like dual diodes, it's worth a thought.
Mouser. Enter 4558 in search window (check the "stocked" box at each step to reduce the clutter). Gets a list of catagories. Under semiconductors, select amplifier ICs. I see 40 responses. There are a bunch of search parameters in columns. Under mounting style click "through hole". Oh, just above in the gray strip is "smart filtering enable" Enable that, it helps. Through hole knocked us down to 14 choices. Over by the left, click APPLY FILTERS. Now the 14 choices should be lined up below. We could search more tightly, but 14 fits on the page, we can see them. I see texas Instruments and Rohm and Fairchild and ST and NJR. Pick one, I go by price usually. They range 33 to 85 cents each. Aha, I fprgot. Look at the remaining parameters and see Maximum Operating temperature. Click 85 degrees and apply filters. The first two choices look good to me at 40-some cents. I buy in bulk and get a price break, but you likely don;t need 25 of them.
5534. Same process. 5534, stocked, smart filtering on, select throughhole, and apply filter. I see 15 returns. Select 85 degree and I see 5. I'd likely pick one of the $1.05 ones.
Search DIP socket, then connectors:IC sockets. Stocked I see 315. Select for 8 pins. Pick one.
I recommend not shotgunning the thing (replacing all the parts). If we replace 40 parts with new, that is 40 new opportunities to put a part in wrong, put in the wrong part, make a bad solder joint, leave a solder bridge, and even one of the new parts could be bad. Fix it first, then do wholesale upgrades as you wish.
I wish you well, young feller. I will be out of town now until next wednesday, so no input from me for a while.
The shape and size of the ICs here is called a DIP. Dual Inline Package. The sockets for them are called DIP sockets. If you see DIP8 instead of just DIP, that simply means an 8-pin DIP socket or IC. They come in other sizes too. PDIP means plastic DIP. That is OK too. SOme DIPs are ceramic, perhaps even yours. Any kind is OK.
The ICs are 4558 and 5534. There will be letters too, like RC4558 or BA4558. Each brand is different letters. But you need them in DIP.
Mouser is a good supplier, but don;t forget Peavey, they sell direct. Prices are not outrageous. You can call them up and ask for a "4558 IC" and a "5534 IC" and "8-pin IC sockets" and they will know. If you are going to order anything else from them already,like dual diodes, it's worth a thought.
Mouser. Enter 4558 in search window (check the "stocked" box at each step to reduce the clutter). Gets a list of catagories. Under semiconductors, select amplifier ICs. I see 40 responses. There are a bunch of search parameters in columns. Under mounting style click "through hole". Oh, just above in the gray strip is "smart filtering enable" Enable that, it helps. Through hole knocked us down to 14 choices. Over by the left, click APPLY FILTERS. Now the 14 choices should be lined up below. We could search more tightly, but 14 fits on the page, we can see them. I see texas Instruments and Rohm and Fairchild and ST and NJR. Pick one, I go by price usually. They range 33 to 85 cents each. Aha, I fprgot. Look at the remaining parameters and see Maximum Operating temperature. Click 85 degrees and apply filters. The first two choices look good to me at 40-some cents. I buy in bulk and get a price break, but you likely don;t need 25 of them.
5534. Same process. 5534, stocked, smart filtering on, select throughhole, and apply filter. I see 15 returns. Select 85 degree and I see 5. I'd likely pick one of the $1.05 ones.
Search DIP socket, then connectors:IC sockets. Stocked I see 315. Select for 8 pins. Pick one.
I recommend not shotgunning the thing (replacing all the parts). If we replace 40 parts with new, that is 40 new opportunities to put a part in wrong, put in the wrong part, make a bad solder joint, leave a solder bridge, and even one of the new parts could be bad. Fix it first, then do wholesale upgrades as you wish.
I wish you well, young feller. I will be out of town now until next wednesday, so no input from me for a while.
That's a serious amount of corrosion! Check all the boards in all the amps and buy enough parts to replace all the suspicious stuff, plus some extras, but don't replace anything else yet. Contrary to popular belief, double leaf sockets are more reliable than the expensive round machined contact ones.
So here is what I've got so far on my Mouser project. Are these going to be fine?
5534
NE5534NG ON Semiconductor | Mouser
4558
MC4558CN STMicroelectronics | Mouser
Also, the two driver transistors seem to be MJ13330 according to the Peavey Cross Reference sheet. But Enzo said a MJ15024 should work. What would be the downsides? Is it not as good as the MJ13330 for the driver transistor purpose? Anyone have a Mouser part number for new TO-3 sockets? I have sockets for Hafler amps and stuff... but they are different. I would need board mounted sockets.
Edit: I can't find an MJ13330 on Mouser. Is that no longer made?
5534
NE5534NG ON Semiconductor | Mouser
4558
MC4558CN STMicroelectronics | Mouser
Also, the two driver transistors seem to be MJ13330 according to the Peavey Cross Reference sheet. But Enzo said a MJ15024 should work. What would be the downsides? Is it not as good as the MJ13330 for the driver transistor purpose? Anyone have a Mouser part number for new TO-3 sockets? I have sockets for Hafler amps and stuff... but they are different. I would need board mounted sockets.
Edit: I can't find an MJ13330 on Mouser. Is that no longer made?
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The ICs should be fine. I'm assuming you have the manual and that's what's specified. The Peavey I worked on used the slightly higher speed JRC parts and somebody subbed them with something slower. The amp turned out to be quite fussy about the opamps and wouldn't meet its specs with a part that really wasn't much different. Always download the datasheet for the actual parts you're using and compare them with the OEM part. There are differences between manufacturers. The slew rates should be the same or you should look for another part.
For the transistors do the same. Download the detailed spec sheets and compare the voltage and current ratings, also the peak current ratings. Speed is less critical, but should be similar to what's being replaced. If you can't get data on the original, at least compare with a known acceptable sub.
(sorry, I don't have the speed here to download a lot of stuff.)
For the transistors do the same. Download the detailed spec sheets and compare the voltage and current ratings, also the peak current ratings. Speed is less critical, but should be similar to what's being replaced. If you can't get data on the original, at least compare with a known acceptable sub.
(sorry, I don't have the speed here to download a lot of stuff.)
Don't assume semis are your only blown up components on the faulty driver board. I had shorted 50v film caps, open resistors, a lot of blown diodes, and some burnt off PCB lands. I still don't know if I have open 50 v caps, all the DVM's with cap tester blew up at work. I just replaced all the e-caps, they were 18 years old anyway. The jfet was blown, one double diode was blown, I sure don't know about the DDT IC, it is too weird but I replaced it. I'm still tracing something that whangs the speaker output to plus rail immediately, probably another blown PCB land or something. I just burned a weekend building a light bulb box that 1. won't electrocute anything with flying clip leads at 120 VAC 2. won't pour broken glass in my organ pedals or bench cushion or the carpet if I knock something off. Has a disconnect, a real 3 prong socket, a circuit breaker, a heat sink and a real grounded metal box. Bleah. I've been putting off this job for 5 months because the blow ups are so expensive with a 1500 watt room heater as a current limiter.
The Peavey semiconductor cross list used to be on electronicsclub.cjb.net posted by Karsilik.
And on the removing the DC protection triac thing- I tried replacing the burnt up lands on the PCB to the triac, and replacing the shorted triac and the shorted diac at the same time as the new output transistors, then powered up and burned the 20 ga leads to the triac off again, plus both triacs, plus one of the diacs. No more. CB never tripped. After everything is working perfectly and the DC on speaker is < 7v (trip point on the diac) the triac will go back in. Not before.
The Peavey semiconductor cross list used to be on electronicsclub.cjb.net posted by Karsilik.
And on the removing the DC protection triac thing- I tried replacing the burnt up lands on the PCB to the triac, and replacing the shorted triac and the shorted diac at the same time as the new output transistors, then powered up and burned the 20 ga leads to the triac off again, plus both triacs, plus one of the diacs. No more. CB never tripped. After everything is working perfectly and the DC on speaker is < 7v (trip point on the diac) the triac will go back in. Not before.
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Enzo. Does Peavey sell replacement driver cards for these amps? One of the cards was really hacked up, and I would rather replace it than make a million jumpers.
One thing that has me confused. All the driver cards are the same in ALL three amps (as in design, and traces.) Sure some boards in the amps are green, and have solder mask, and the others are like Hafler style, and a phenolic board w/o a solder mask. I have three phelonic unmasked boards, and 3 green masked ones.
Anyways, all of the boards have a jumper in the CR5 position. One of the boards has a diode. Seems to be that goofy dual diode thing.
What is this diode's purpose, and why are all the there boards just using a jumper. FYI, the amp that is 100% working like a champ has a jumper, and not that diode.
In other sad news, one of the thermal sensors is missing a rivet. And when apparently the sensor swiveled, and an the AC wire made contact with the grounded lead that goes from the terminal strip to the board (a dual diode is on this terminal and mounted to the heatsink, and has a molex connector).
That channel died quickly, bu the bulb didn't go bright. Thankfully the working driver card I was using to test that channel is fine. So I took that card and put it in Channel A, and so we have one working channel on amp 2!
Amp 1 is the one thats working fine and that I was concerned about. I'm leaving Amp 3 out of this discussion until amp 2 is working.
I really hate how Peavey used rivets on parts of this amp. They are a pain in the rear to drill out, and make more work.
One thing that has me confused. All the driver cards are the same in ALL three amps (as in design, and traces.) Sure some boards in the amps are green, and have solder mask, and the others are like Hafler style, and a phenolic board w/o a solder mask. I have three phelonic unmasked boards, and 3 green masked ones.
Anyways, all of the boards have a jumper in the CR5 position. One of the boards has a diode. Seems to be that goofy dual diode thing.
What is this diode's purpose, and why are all the there boards just using a jumper. FYI, the amp that is 100% working like a champ has a jumper, and not that diode.
In other sad news, one of the thermal sensors is missing a rivet. And when apparently the sensor swiveled, and an the AC wire made contact with the grounded lead that goes from the terminal strip to the board (a dual diode is on this terminal and mounted to the heatsink, and has a molex connector).
That channel died quickly, bu the bulb didn't go bright. Thankfully the working driver card I was using to test that channel is fine. So I took that card and put it in Channel A, and so we have one working channel on amp 2!
Amp 1 is the one thats working fine and that I was concerned about. I'm leaving Amp 3 out of this discussion until amp 2 is working.
I really hate how Peavey used rivets on parts of this amp. They are a pain in the rear to drill out, and make more work.
SBS, not a diac.
MBS4992, silicon bidirectional switch.
http://www.newark.com/solid-state/2n4992/bilateral-switch-5ma-to-92/dp/67R1097
Leaky drivers and Vas will cause the triac to dump on start-up.
MBS4992, silicon bidirectional switch.
http://www.newark.com/solid-state/2n4992/bilateral-switch-5ma-to-92/dp/67R1097
Leaky drivers and Vas will cause the triac to dump on start-up.
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Does PV sell them? They would if they had them in stock. You'd have to ask their parts department if they still have any.
CR5? It is not on the schematic, I bet you see it on the layout. I see it as having been eliminated. Look just above it there is a jumper J right left of CR3. It was once a diode in the same manner but for the other rail, I would wager. If you look at the overall circuit, those diodes would have provided a litle isolation for the 5534 from the 15v rails. I think they decided it was not needed. An older board could still have one, or some tech could have discovered it like you did, and decided he'd better install one. The wire is fine.
They put rivets in things that rarely have to come out. They are secure and mostly do not fall out, not on their own. Screws and nuts are sometimes separated, and they flop around the circuit boards shorting things out. I got no issues with a 1/8 drill, ZZZZZZ and it is out. I have a pop rivet gun in my drawer and some various rivets, I can put anything back together in no time flat.
The big power switch triac in th bottom is riveted.
CR5? It is not on the schematic, I bet you see it on the layout. I see it as having been eliminated. Look just above it there is a jumper J right left of CR3. It was once a diode in the same manner but for the other rail, I would wager. If you look at the overall circuit, those diodes would have provided a litle isolation for the 5534 from the 15v rails. I think they decided it was not needed. An older board could still have one, or some tech could have discovered it like you did, and decided he'd better install one. The wire is fine.
They put rivets in things that rarely have to come out. They are secure and mostly do not fall out, not on their own. Screws and nuts are sometimes separated, and they flop around the circuit boards shorting things out. I got no issues with a 1/8 drill, ZZZZZZ and it is out. I have a pop rivet gun in my drawer and some various rivets, I can put anything back together in no time flat.
The big power switch triac in th bottom is riveted.
They have one left... for $129
I'll just jumper parts of the board where traces have lifted. Anyways, notice the driver cards have a lot of MPS parts. I can't seem to find them from Mouser. I know I could go to Peavey, but I would rather go with mouser for parts.
The Peavey cross reference list doesn't show any replacements that I can find. I basically want to have a back up of ALL the semiconductors that are used of the driver card. Are some of these unobtainable? If they are, I'll sell both amps, keep or maybe sell the one that works 100% and go back to Hafler, and get a DH-500. I know Hafler amps inside out.
I'll just jumper parts of the board where traces have lifted. Anyways, notice the driver cards have a lot of MPS parts. I can't seem to find them from Mouser. I know I could go to Peavey, but I would rather go with mouser for parts.
The Peavey cross reference list doesn't show any replacements that I can find. I basically want to have a back up of ALL the semiconductors that are used of the driver card. Are some of these unobtainable? If they are, I'll sell both amps, keep or maybe sell the one that works 100% and go back to Hafler, and get a DH-500. I know Hafler amps inside out.
MPS numbers are industry numbers. All these transistors are just common types under the skin, Peavey will either have them or a good sub for them until the end of time. It is remarkable how NOT sensitive these circuits are to substitutions. If you can't find some particular type in the future, call Peavey service and ask what they are using in its place now. MPSU10, MPSU60 are examples. That small tab transistor package is obsolete, but 300v transistors are easily obtained. I still have them in stock, but when they are gone, I have no doubt I will have plenty of options to chose from. Ask Peavey. Particular numbers may become unobtainable, but equivalents will be around as long as there are transistors.
All reasearch here from Mouser.
MPS6530, Mouser non-item, so use MPS6531, they have 8000 of them on hand at 7 cents each. Stock number:
512-MPS6531_D75Z
MPS6533, use MPS6534. They have close to 15,000 in stock at as low as 9 cents each:
512-MPS6534_D75Z
Those subs from PV crossref guide.
(SJE)6018 and 6019 are MJE340 and MJE350. Not MPS, but there they are anyway, large amount in stock, cheap.
All reasearch here from Mouser.
MPS6530, Mouser non-item, so use MPS6531, they have 8000 of them on hand at 7 cents each. Stock number:
512-MPS6531_D75Z
MPS6533, use MPS6534. They have close to 15,000 in stock at as low as 9 cents each:
512-MPS6534_D75Z
Those subs from PV crossref guide.
(SJE)6018 and 6019 are MJE340 and MJE350. Not MPS, but there they are anyway, large amount in stock, cheap.
List
Heres what we got so far on the list of my next Mouser order.
A 4580 to replace the 4558 RC4580IP Texas Instruments | Mouser
A 5534 OP Amp SA5534AP Texas Instruments | Mouser
1N4007 diodes (already have them, so no need to order them)
MPS6534 (replaces MPS6533) (replaces transistor Q8) MPS6534_D75Z Fairchild Semiconductor | Mouser
MPS6531 (replaces MPS6530) (replaces transistor Q7) MPS6531_D75Z Fairchild Semiconductor | Mouser
2N5461 (Q1) 2N5461 Fairchild Semiconductor | Mouser
2N5400 (Q2)
NO longer made.
Will a 2N5401 work?
SPS690 (Q3) Can't find it on Mouser. What can substitute it?
TI923 (Q4) Can't find it on Mouser. What can substitute it?
Q6 (Peavey: 7204) (MPSU10) Can't find it on Mouser. What can substitute it?
Q5 (Peavey: 7205) (MPSU60) Can't find it on Mouser. What can substitute it?
MJE340 (Q9) MJE340G ON Semiconductor | Mouser
MJE350 (Q10) MJE350G ON Semiconductor | Mouser
CR6 and CR10 are 40102 zener diodes. Can't find them on Mouser either.
No, not all of these components are bad, but I want to order them and add them to my shop so when they do fail or are needed I have them. The transistors (TO-92) are in touch shape. Some have badly corroded leads, others aren't even on the board.
Heres what we got so far on the list of my next Mouser order.
A 4580 to replace the 4558 RC4580IP Texas Instruments | Mouser
A 5534 OP Amp SA5534AP Texas Instruments | Mouser
1N4007 diodes (already have them, so no need to order them)
MPS6534 (replaces MPS6533) (replaces transistor Q8) MPS6534_D75Z Fairchild Semiconductor | Mouser
MPS6531 (replaces MPS6530) (replaces transistor Q7) MPS6531_D75Z Fairchild Semiconductor | Mouser
2N5461 (Q1) 2N5461 Fairchild Semiconductor | Mouser
2N5400 (Q2)
NO longer made.
Will a 2N5401 work?
SPS690 (Q3) Can't find it on Mouser. What can substitute it?
TI923 (Q4) Can't find it on Mouser. What can substitute it?
Q6 (Peavey: 7204) (MPSU10) Can't find it on Mouser. What can substitute it?
Q5 (Peavey: 7205) (MPSU60) Can't find it on Mouser. What can substitute it?
MJE340 (Q9) MJE340G ON Semiconductor | Mouser
MJE350 (Q10) MJE350G ON Semiconductor | Mouser
CR6 and CR10 are 40102 zener diodes. Can't find them on Mouser either.
No, not all of these components are bad, but I want to order them and add them to my shop so when they do fail or are needed I have them. The transistors (TO-92) are in touch shape. Some have badly corroded leads, others aren't even on the board.