I'm the newbie! And I got questions, many questions!

[steve523]

I've been teaching myself electronics for about a year now, have lots of experience chasing wires but no circuit card experience until this undertaking. Man this stuff requires the patience of Job! I used up all my cuss words the first couple months I was doing this stuff!

Someone gave me a Peavey XR1600 powered mixer and I did some work on the amp, but I don't have a schematic, if anyone can point me to one I would be very grateful. And I have questions about part numbers. Both are 8 pin Dip. One is 70487478, this number looks very Peavey but I've been searching the web for hours and no good result. I tried different segments of the number, it's a Hitachi so I ran combinations of the number on an HA prefix (close finds but no matches). The other part number is RA3678C, that looks Raytheon, but same thing, lots of near misses.

When I was working BJT issues I found a good cross reference for Peavey numbers, but no IC's are included. Here's the link for the xref list I found.
I'm providing it because I don't want to be a freeloader first time on a post.

http://xoro3.tripod.com/elektronik/d...r/karsilik.pdf

So, anybody know what these are? I figure dual or single op amp, but now that I have the darn thing back together, I don't want to pull it apart to see the traces. This reminds me of some guy I worked with once, used to say "Sometimes the hard way is the easy way." This is one of many moments I realize he was right. I was hoping to get good i.d. and datasheets on these to see if I could maybe throw some OPA2604's in before I stick it in the mixer. Tried Datasheet Archive, Alldatsheets, and others but no luck.

Another thing, since I started messing with this and a couple other audio devices. I found out that ON semiconductor has a real good line of Motorola's old devices, but they update the part numbers to fit them in with their production line ( I guess), If you find a close match look at the data sheet, odds are it's a good replacement

Also, another good site I found for test equipment schematics. B.A.M.A. (boat anchor manual archive). The main site is a university site and it won't download for you if you try, gotta be a registered student or something, but there's a link on that page to an EDEBRIS mirror site. The manuals are in either Winrar .rar or Adobe .pdf format. I have an almost complete electrical bench thanks to these guys!

If anyone can help me please let me know!

[Enzo]

COntact customer service at Peavey for any schematic of their products.

Here is the factory semiconductor cross reference, and it does include ICs.

The 478 is an OTA. SPecifically the CA3094. It is not a plain op amp.

&0487478 is the PV part number, and th parts are usually marked 87478. That is a Peavey part number, not an industry part number.

Motorola semiconductor parts became On Semi some time back. They don;t usually change part numbers. When they convert an old transistor to RoHS, they just add G to the end, as in MJ15024 becomes MJ15024G. G meaning green, as in ecologically friendly. The regular and green versions are completely interchangeable.

I don;t remember them using 478s in the mixer part, so I am assuming you mean the 478 in each power amp channel.. You can remove it and operate the amp without it during test, if you think it might be part of whatever problems you have. That IC acts as the control element in the DDT or anti-clipping limiter.

[steve523]

Thanks Enzo! I'll be sure and get with the Peavey folks. It's tough without the map! I work in a place where I frequently have no tech data other than an operator's manual and the equipment has been modified one or more times by someone trying to fix something without leaving any information on what they've done or why they did it. It's maddening to deal with, but my success rate is better than they've seen so it works out. I work with a guy that was an employee at a sound company back in the day, called Nova 8 (Omega 8 maybe?). He's been mentoring me in this self-teaching process, and when I'm uncertain with audio problems he's always willing to help, but I try not to push him for too much. Thanks again for the info!

[steve523]

Newbie again

Well, I contacted Peavey but never got a reply, so I bought a copy of their schematic for 20 bucks.