Peavey CS-800 Issues

If I am replacing the whole row, then fine, use either one, but if I have only a couple bad parts, then I either stick to the MJ15024 or replace the whole row with the 211xx. And then the question becomes which is cheaper, two 15024s or six 211xx?

You should replace an entire row even if one goes out. If you want optimal thermal tracking, you really want parts from the same lot. MJ15024's made decades apart are probably enough different to warrant it - especially if the "good" ones that are left have been thermally stressed to near death. If one goes out, there was a reason.

As for what to use for the MPSU parts - use MJE340/350. Preferably ST parts, they have higher fT than On, and I trust them more than any of the no-names. MJ1503x will be fine for predriver duty, but less than optimal for the VAS or current source. The die is too big, and has a lot more capacitance.
 
Still no reply. I'll have to call them I guess. I've*done that, and never spoke with anyone. I was on hold for an hour and a half the last time. 🙁 hopefully I'll be lucky this time. I know I should call first thing like Enzo says, but my sleep schedule is outta wack. I don't get up until 10, or even noon.*
 
Well I called and got through. The MPSU10 (70407204) is still available. The cross reference sheet states the MPSU10 can be changed to a 2N6557. Mouser doesn't carry either. They don't have any other subs.

Now for the MPSU60 (70407205) they told me it's replacement is 30467205. He didn't know what the actual transistor was (eg 2NXXXX) Can Enzo look this up for me? I believe one is only $0.49, and the other is $1.49. So not to bad. That said, If I can replace the MPSU60 with a MPSW92 (PNP), and MPSU10 with a MPSW42 (NPN) and this would be fine, then I'm all set. Both the MPSW92 and MPSW42 can be purchased from Mouser.
 
I think the MPSW parts are closer to the original than the 2N6557 is.

The 2N part is slower, 20Mhz vs 50Mhz.

The 2N part does have a metal tab and has greater power handling than the original MPSU part, the MPSW part has the same power rating as the original MPSU part.
 
If they told you a sub, then believe them. I mentioned before that they have reasonable prices. Buy it there. Their look up sheet is more recent than mine.

The parts guys may not know what is under the skin of that house number, but I;d bet the service guys do.

MPSU10/60 are 300v 500ma parts, so any numbe of parts that meet those specs will work. MJE340/350 probably are fine. 2N6557 or 6558 would be fine.

And those MPSW types look like they'd be fine also. Looks like Mouser wants 40 cents.


I think Peavey does an amazing job supporting this product - and many others. After all the thing came along in the 1970s. How many other companies support products of that age?
 
As I said:
Their look up sheet is more recent than mine. I could go download the current one, then I;d have the same one they have.

All I can do is get the information from them. If they don't know, they can;t tell me. If it comes down to asking the repair guys, I'm not going to call them just so you don't have to, y'know? Ask Gene.

And if we use the MPSW parts, then it becomes moot.
 
No, I ALWAYS make a drawing of it any time I touch it. If I find the wires out of place due to previous servicer attempts or whatever, I get out the schematic and trace where things should connect.

Did you not say you had several of these amps and some are working? Open one up and make a diagram from that.


I do have a power switch wiring guide, it has SOME of the terminal strip wiring. Here...
 

Attachments

Heres my completed list of all the semiconductors for the CS-800 driver card.

A 4580 to replace the 4558 RC4580IP Texas Instruments | Mouser

A 5534 OP Amp SA5534AP Texas Instruments | Mouser

1N4007 diodes 1N4007 Fairchild Semiconductor | Mouser

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

2N5401 (Replaces 2N5400) (Q2)

2N5086 (Replaces SPS690) (Q3) 2N5086 Central Semiconductor | Mouser

MPSA18 (Replaces TI923) (Q4) MPSA18RLRMG ON Semiconductor | Mouser

MPSW42 (Replaces MPSU10) (Q6)MPSW42RLRAG ON Semiconductor | Mouser
MPSW92 (Replaces MPSU60) (Q5) MPSW92RLRAG ON Semiconductor | Mouser

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. 🙁[/QUOTE]
 
In post#22 of this thread on July 25 I said
"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."

Did you do that? On it is the listing for all the generic numbers behind the house numbers.

40102 is a 1N4744, very common, which I pointed out in post #41
 
Mouser is a great supplier, but they don't always have everything. Other good suppliers are Digikey, Allied, Newark. Those are similar to Mouser in their nature, but may have different selections. I appreciate wanting to make just one order instead of paying multiple shipping bills, so then we have to adapt.


Some parts like the MPSU10 are simply obsolete. others may have a brother part that is pretty much exactly the same, but has a higher voltage rating, so the supplier only carries the higher voltage part. That explains the instances on your list where we substituted a different part just a couple digits different.