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Good direct subtitution for Op-amps inside Technics CD question?

FileFixer

FileFixer

Well-Known Member
I wan to change some Op-amps in my Technics CD player but I`m not sure for what Op-Amps...
Red colors on schematics shown Op-ams what is actualy now placed into the CD Player...

Changes.jpg


On previous SL-PS770A model Op-amps was LM833 and into new model SL-PS770D that Op-amps was changed to M5238 and RC4580 Op-amps. As I can see on schematics and actual state inside CD Player all other components is same as on previous model A. Only what is changed are capacitor into the Low pass filter on output with 6.1 kOhm resistor.
From that situation I can see that is LM833 and BA4560 can to be directly replacable with LM5230, RC4580, BA4560 and it seems that all of that Op-amps is interchangeable from one to another...
LM833, M5238, RC4580, BA4560 is direct replacement between themselves.
I`m looking for something better Op-amps like AD826, OPA2132, OPA2134, OPA1642, LM6172 etc.
Is it possible to drop in some better Op-amp insted of that what in now in place? Any sugestions will be good?

Thanks
 
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By the look of the circuit diagram, any common low noise dual OP amp will fit. OPA2134 with JFET front end or NE5532 would be O.K. One relevant point is that the supply voltage as shown is about +/- 6.2vdc. This is close to the minimum supply voltage for any of these devices (including the one's fitted). In most cases the audio performance (noise levels etc) improves when the supply voltage is towards the upper end of their range. Most OP amp circuits run at about +/-15vdc. Provided that nothing else is affected, it may be worth investigating whether it is possible to increase the PSU supply voltage to these devices before/instead of changing them as they are low noise audio devices anyway.
 
OPA2134 have ±2.5 V to ±18 V operating voltage. I build inside my TT preamp with that chips and it have nice sound, soft and pleasure. Also build another MM preamp with same chip. When I compare Technics SL-PS770D with Pioneer DV-300 DVD Player then i feel that Technics somewhere lack in sound stage. Pioneer is more attractive on bass and high frequency then Technics, on my ears I hear something that Pioneer have more dynamics and clearer sound.
My TT with that OPA2134 sounds more pleasure than any CD if I play it from Technics CD but Pioneer DV-300 shows own teeths and show who is the boss on dynamic range.
This is Op-amps what I found that can be replaced with this what is curently inside Technics... I dont know is it all of these Op-amps can be droped in and direct interchangeable with that from inside but I would like to know the possibilities and the difference in sound...

AD825
AD826
LM833
RC4580
BA4560
OPA2209
LME49720
OPA2134
OPA2132
LM4562
LT1355
LT1358
NE5532
TL072
LM833
NJM4558
NJM4559
NJM4560
NJM4562
NJM4565
NJM4580
 
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