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.
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.
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
Regards
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.
which often lack ground planes and other HF layout techniques.
A few corrections if I may.
The Nakamichi ec-200 is a Car audio, Discrete, Active, Two way crossover for bass to midrange frequencies. 50 - 220 Hz.
The Nakamichi ec-200h is a Car audio, Discrete, Active, Two way crossover for midrange to treble frequencies. 1.8 - 6 Khz
So these are Not digital devices, Nor are they graphic equalisers.
The Nakamichi ec-200 is a Car audio, Discrete, Active, Two way crossover for bass to midrange frequencies. 50 - 220 Hz.
The Nakamichi ec-200h is a Car audio, Discrete, Active, Two way crossover for midrange to treble frequencies. 1.8 - 6 Khz
So these are Not digital devices, Nor are they graphic equalisers.
Thanks for the additional information and pictures.
Yes. we are talking about Crossovers not Graphic Equalisers !
In the end I swapped to the DBX234XL and have nearly finished upgrading a pair of those to audiophile level.
Upgraded the capacitors to Wima FKP and Nichicon UKZ.
Rolled the Op Amps to OPA 2828 (dual OPA828 ) and OPA 1644 for the quads.
I had to make a custom PCB for the 2828 as well - (if anyone is interested to buy some OPA2828 PCB's let me know).
Yes. we are talking about Crossovers not Graphic Equalisers !
In the end I swapped to the DBX234XL and have nearly finished upgrading a pair of those to audiophile level.
Upgraded the capacitors to Wima FKP and Nichicon UKZ.
Rolled the Op Amps to OPA 2828 (dual OPA828 ) and OPA 1644 for the quads.
I had to make a custom PCB for the 2828 as well - (if anyone is interested to buy some OPA2828 PCB's let me know).
