Modern replacements for CA3140 and NE531 (Scamp S04 EQ)

Help Support GroupDIY:

sws2h

Well-known member
Joined
Nov 22, 2009
Messages
103
Location
Nashville, TN
I have several Scamp S04 EQs with various issues. 2 work except for the mid band, and one doesn't pass signal.

These use either CA3140 or NE531 op amps and they must be able to be used interchangeably because between the 3 modules with issues they are swapped around.

What is a modern drop in replacement? Unfortunately I can't find the schematic for the S04 anywhere.
 

JohnRoberts

Well-known member
Staff member
Moderator
Joined
Nov 30, 2006
Messages
21,877
Location
Hickory, MS
The CA3140 is old BiMos op amp... I suspect a modern bifet (something like TL071) would probably make a suitable replacement. NE531 is a high slew rate old bipolar, for reproducing audio we don't need 35 V/uSec. A ne5534 would probably be adequate. There are any number of modern replacements.

JR
 

mjrippe

Well-known member
Joined
Dec 27, 2011
Messages
2,748
Location
Brooklyn, NY
Schematics are attached. If you want to stick with the originals, the CA3140 is still available. Well, Mouser and Digikey don't have them in stock but they are still an active part number. I have some I can spare if you want to DM me.
 

Attachments

  • scamp-s04.pdf
    231.3 KB · Views: 27

sws2h

Well-known member
Joined
Nov 22, 2009
Messages
103
Location
Nashville, TN
Schematics are attached. If you want to stick with the originals, the CA3140 is still available. Well, Mouser and Digikey don't have them in stock but they are still an active part number. I have some I can spare if you want to DM me.
Thanks for the schematic that's a huge help! I tracked down some RCA CA3140 on eBay. Do you have any other Scamp schematics?
 

Latest posts

Top