? about LM3080N used in a peavey amp

[tim]

Hey all,
I have a Peavey mixer amp type box on the bench that has a bad LM3080N (PV P/N 70413080). It says in their parts list that it is a "hand picked part". I called Peavey to order one and they only sell a little kit, probably like their TL604 IC replacement. I see LM3080N's on other sites like Mouser, etc. Is this IC so special that they need to be handpicked for Peavey's application or would I be able to buy one from somewhere other than Peavey and still have it work?
I don't have the actual mixer amp P/N as I am on the road and not at my shop right now but if you need to know what it's in, I can get that later today when I get back to the shop.
Thanks,
Tim
Electronic Sound Technologies

[Gtr_tech]

Its just a CA/LM3080 transconductance opamp....pro'bly used in the compressor circuit. I wouldn't worry about chasing down a "selected" part. You should be ok with a garden variety 3080.

[tim]

Their Parts list for that amp expressly says not to use that part unfortunately. Here it is copied verbatim:
Regular P/N is LM3080N , for Peavey, replaces old # 70487478 and 87478, Do NOT use CA3080
the plot thickens...
Tim
Electronic Sound Technologies

[Gtr_tech]

Well I find that to be strange. I'd call a tech at Peewee and ask why this is. 3080s are common in VCA type circuits and I've never seen reference to selected parts.

[tim]

yeah, I think I'll call them when I get to the shop today or try Monday...I'm sure they won't be anywhere near their shop coming up to Friday closing time.

I'll post what amp it is when I get back and see what kind of circuit it is used in...it was loading down the -16v circuit that's derived from the -60 volt circuit...was causing the amp to DC out.

[tim]

OK, I'm back.
The amp in question is an XR600F.
I have the schematic but not sure how to cut and paste from a PDF doc so I can't paste it here...for those that might have a schematic, it's U101 and U201 (U201 being the culprit)...
Anyway, Peavey says they have a work around they can sell me for $15 but not in stock right now...I may go that route when they come in...

[Enzo]

I looked into this once and forget what the deal was. I know the orginal 87478 was a CA3094, not a CA3080. Without looking up the sheets, both were OTAs, but one added an open collector transistor at the output. Depending upon the application and how the sockets were wired, sometimes you could use the "wrong" one in a particular spot, but other places it wouldn't work. In other words some circuits ignored the transistor part, so you could use the one without if you preferred. But when they did use it, then yuo had to get the right type.

Now the selection involved here I don;t recall the particulars of. Call Gene Ford at the factory and ask him, he's a helpful guy. I don't remember if it mattered which vendor or what

[tim]

The IC's that are in there now are Harris parts...

I think I'll call the Factory next week...will they talk to a "non-authorized " center? When I worked for a large repair center a few years back that was authorized for Peavey repairs, they were always very helpful when I had to call but not sure if they are the same way with a small place like mine...

[Enzo]

Talk to Gene. PV is far and away the most customer friendly factory on this planet.