Marantz CD5400 Output Stage

[iamwhoiam]

Hi,

I was just wondering what modifications I can undertake on the output stage from the DAC of the Marantz CD5400 cd player.

Currently on my list are:

- Remove or jumper across muting transistors
- Replace output capacitors (C210/310 between o.amp output and muting stage) with 10uF polypropylenes/blackgates

The output schematic:


Some Questions:
1) Can I jumper across the resistors in the output signal path? Or will this mess up impedance?
2) OpAmp rolling: The current opamp uses bipolar transistors, so would the LM6172 (with bipolar imputs) be suitable as a drop-in replacement or can I use a better opamp (AD8620 or OPA2132 etc)
3) Are there any other modifications that you guys suggest?

Thanks in advance
-andy