Tascam DR100 Mkii opamp upgrade

[Jim50hertz]

I've been seeking info on upgrading the DR100.

It seems there may be some mods out there but none that are immediately apparent.

I thought perhaps I could replace the op-amps with higher quality ones to improve gain and S/N.

I found a page with some gut shots...

http://blog.sina.com.cn/s/blog_4e45856f0102v1nh.html

Anyone care to take a stab at which parts may be good to replace and with what? (pic 5 the JRC 8009s?)  I'm thinking along the lines of the Jim Williams mod of the DR70.

 

[Khron]

First of all, it would help if you knew the role of those opamps in the circuit.

Second, the first row of the markings on JRC chips is the actual part number, which i think is "2121", which would make them NJM2121.

https://www.njr.com/semicon/PDF/NJM2121_E.pdf

Good luck finding a drop-in replacement (unlikely to happen).

Gain is usually set via resistors, so swapping opamps won't do anything for that. S/N ratio, that may very well depend on the circuitry outside the opamps.