Hello,
My name is Olek, I'm from Poland, and sorry for my english.
I have very important for me question/request about Integrated Amplifier Marantz PM7000 (or PM8000). I have PM7000 (and Marantz CD6000-after upgrade) and I want to change op-amps (Operational Amplifiers) inside to better ones. But I don't know which is responsible for what audio module/unit/signal_patch (I don't have any electronics and elements scheme or chart). I can see on the little plate inside (near the volume potentiometer/regulator) four op-amps (I think all are dual, for L and R channel):
1. 7501 - NJM2068DD (7501, 7502, 7503 are on the parallel board/plate to basis-ground)
2. 7502 - NJM2068DD
3. 7503 - .................. ?
4. .... ? - NJM2114D (it is only one op-amp on board/plate with the volume potentiometer/regulator, board parpendicular to basis-ground)
Which is to tone control in bas ?
Which is to tone control in treble ?
Which is to volume control ?
What for is the fourth op-amp ?
Maybe I'm wrong and their destiny and using is even different ?
Maybe photos with these op-amps will be helpfull: http://garmin.webpark.pl/pm8000.htm
(pictures nr: 7 - there are 3 op-amps, and 8 - there are 1 op-amp)
I listen only in Direct mode/patch (tone control and balance are disabled). Which is the most important to change for me ?
I want to change e.g to: OPA2604 or AD825.
I will be very grateful, much obliged and appreciate.
Thank you very much.
Best Regards
Alex2
My name is Olek, I'm from Poland, and sorry for my english.
I have very important for me question/request about Integrated Amplifier Marantz PM7000 (or PM8000). I have PM7000 (and Marantz CD6000-after upgrade) and I want to change op-amps (Operational Amplifiers) inside to better ones. But I don't know which is responsible for what audio module/unit/signal_patch (I don't have any electronics and elements scheme or chart). I can see on the little plate inside (near the volume potentiometer/regulator) four op-amps (I think all are dual, for L and R channel):
1. 7501 - NJM2068DD (7501, 7502, 7503 are on the parallel board/plate to basis-ground)
2. 7502 - NJM2068DD
3. 7503 - .................. ?
4. .... ? - NJM2114D (it is only one op-amp on board/plate with the volume potentiometer/regulator, board parpendicular to basis-ground)
Which is to tone control in bas ?
Which is to tone control in treble ?
Which is to volume control ?
What for is the fourth op-amp ?
Maybe I'm wrong and their destiny and using is even different ?
Maybe photos with these op-amps will be helpfull: http://garmin.webpark.pl/pm8000.htm
(pictures nr: 7 - there are 3 op-amps, and 8 - there are 1 op-amp)
I listen only in Direct mode/patch (tone control and balance are disabled). Which is the most important to change for me ?
I want to change e.g to: OPA2604 or AD825.
I will be very grateful, much obliged and appreciate.
Thank you very much.
Best Regards
Alex2
Hello Olek, your post should be in another section I think. This is the digital section. Never mind. I think OPA2604 can be used for all opamps but a service manual/schematic would be very helpful. The NJM opamps ( all bipolar dual opamps BTW ) that are in the amp are lousy except for the reasonable 2114. OPA2604 outperforms them all. 2068 has a slewrate of 6V/us, 2114 has 15V/us and a max. output current of 60 mA ( headphone amp ? ).
Max. power supply voltage of 2068 is +/- 18 V, 2114's max. supply voltage is +/- 22 V. You're safe with OPA2604.
You can leave the opamps in the tone control section where they are since you don't use the tone control. Replacing them for OPA2604 won't hurt.
Max. power supply voltage of 2068 is +/- 18 V, 2114's max. supply voltage is +/- 22 V. You're safe with OPA2604.
You can leave the opamps in the tone control section where they are since you don't use the tone control. Replacing them for OPA2604 won't hurt.
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