Equivalent chips

[mata_haze]

Hi Everyone,
I am currently fixing an old Studer 189 MKIII console for a customer of mine and I am struggling to find drop in equivalences for the following chips:

LM301
uA748
TBA 931

any suggestion much appreciated!

Mattia

 

[Brian Roth]

I found the 301 and 748 opamps in plastic DIP packages on the Mouser website (the pic for the 748 shows surface mount, but the spec sheet says the stocked number is 8 pin DIP).

Bri

 

[Harpo]

LM301 in 8pinDIP are still and cheap avail. @reichelt.de. For the cost of the TO99 case variant you could solder some legs on the DIP chip pins.

for ua748, (universal single bipolar lower offset OP with freq.compensation and external offset adj.) depending on case (8pinDIL, 14pinDIL, MetalCan TO99), direct replacement might be SN52748, SN72748 or TOA2748. Depending on task, ua741 might do it as well.

for TBA931 there is no drop in replacement. Have a look at ftp://ftp.studer.ch/public/Products/Revox/Revox_A720/TBA931_Replacement_Rev2.pdf

 

[cadds]

Hi Folks, i used to service Revox / Studer back in the 80/90s and we always used an SN76131 as a direct replacement for the TBA931 with no ill effects particularly within the servo motor circuits and VU drivers worth checking out.

 

[JohnRoberts]

You should be able to find more modern single op amps in 8 pin dip package to replace the LM301 and  748, which were not very fast or high performance. You may need to remove superfluous compensation caps.

I would be tempted to decide which selectively based on impedance of feedback networks, drive requirements, and the like.

I do not have any experience with TBA 931

JR