Nakamichi ec-200 - opamp rolling the RC4560 with opa2828

[ZestClub]

The Nakamichi ec-200 series of graphic Equalisers are recognized as one of the best sounding of the analog era.

One of the reasons for this is the use of the RC4560 dual op amp (2005), while many other manufacturers were and are still using the old TL074 (1978) op amps.
Its possible that the RC4560 circuit could be improved further and rolled with the newer and better opa2828 (2018) op amps.
Looking into the circuitry at the moment.

I am not a fan of DSP's with there low price ADC/DAC combinations limiting the sound quality in my chain.

NAKAMICHI ec-200 EC-200H SERVICE MANUAL AND SCHEMATIC.

 

[NanoFarad]

You better leave it as it is, but changing old electrolytics wouldn't be a bad idea. But for that you need good desoldering skill.

Regards

 

[rayma]

Wide bandwidth op amps may not work as well as they should when installed on old pcb designs,
which often lack ground planes and other HF layout techniques.