Did anyone try to remove the muting transistors in CD6000 ?
Need help to locate the transistors and am courious on how (and if) it affects the sound quality.
I know this was covered before but found threads only related to older marantz models.
Seems easiest and cheapest mod, if not a legend.
Thanks for your answers !
Need help to locate the transistors and am courious on how (and if) it affects the sound quality.
I know this was covered before but found threads only related to older marantz models.
Seems easiest and cheapest mod, if not a legend.
Thanks for your answers !
Transistors you will have to remove are: 7227, 7228, 7229, 7230. All 4 transistors are the same type: 2SC2878.
Since you'll have to remove the main PC board, it is an excellent opportunity to replace the op amps with AD826, or AD8066 (with adaptor boards + some attention to keeping 8066 cool!). Remove the existing cheep RCA connectors and install high quality ones - no drilling required! Feed the output signal from the output pins of these AD amplifiers straight (no PCB tracks) to these high quality RCA connectors (bypassing HDAM circuits all together!) via coupling capacitors of higher quality: try some film and foil ones, for a start you could try WIMA 4.7uF 250V MKP4 or MKP10. Black Gate type C (10uF / 50V) are good. Reasonably priced and very good are AURI caps: 4.7uF / 200V. Load the OP outputs with 100pF and 100Kohm in parallel at the RCA connectors.
And be amazed....
Good luck
Nick
Since you'll have to remove the main PC board, it is an excellent opportunity to replace the op amps with AD826, or AD8066 (with adaptor boards + some attention to keeping 8066 cool!). Remove the existing cheep RCA connectors and install high quality ones - no drilling required! Feed the output signal from the output pins of these AD amplifiers straight (no PCB tracks) to these high quality RCA connectors (bypassing HDAM circuits all together!) via coupling capacitors of higher quality: try some film and foil ones, for a start you could try WIMA 4.7uF 250V MKP4 or MKP10. Black Gate type C (10uF / 50V) are good. Reasonably priced and very good are AURI caps: 4.7uF / 200V. Load the OP outputs with 100pF and 100Kohm in parallel at the RCA connectors.
And be amazed....
Good luck
Nick
Hi, thanx for your help !
- Could easily detect the transistors. Just a hint for anyone to try this:
If you´re not very good at it, dont unsolder the transistors, just cut the connections.
I almost ruined the board.
Bridged the 4 x 220nF capacitors (2219-2222) too, which changed even more to the better than the transistors.
r!sc!: yes, i´m using op275gp too, easily to order from the analog.com site.
Still: too much treble and not enough texture in the lower mid range for my taste. But thats the all in all Marantz sound, I guess.
- Could easily detect the transistors. Just a hint for anyone to try this:
If you´re not very good at it, dont unsolder the transistors, just cut the connections.
I almost ruined the board.
Bridged the 4 x 220nF capacitors (2219-2222) too, which changed even more to the better than the transistors.
r!sc!: yes, i´m using op275gp too, easily to order from the analog.com site.
Still: too much treble and not enough texture in the lower mid range for my taste. But thats the all in all Marantz sound, I guess.
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