Modding Denon DCD-695

Tolu

Member
2007-03-27 12:40 pm
I am pondering whether it make sense to mod an old Denon DCD-695 CD-player. I have no service manual and so it's a little bit difficult for me.

I have attached a picture of the pcb. It has 2 BB PCM61P 18Bit DACs on board. But I think output stage is very cheap. If someone is interested and capable to help I can add some more detailed pictures.
 

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OneyedK

Member
2007-10-02 9:57 pm
You took a picture of the DAC chips and their surroundings,
but I don't see the rest of the output stage.

The classical Denon PCM61P output stage consists of 2 x NE5532, and if you are lucky, they used 2x OP271.

This can be improved by changin them into these:
http://www.cimarrontechnology.com/index.asp?PageAction=VIEWPROD&ProdID=38

Further improvement could be to route a high-quality capacitor (47µF) from Pin 7 of the opamp chips of each channel directly to the cinch output. (remove all resistors, transistors and capaciors in the path)
Make sure you take away the resistors that feed the headphone-amp too.

Spending more money on a DCD-695 is a downright waste.
But these upgrades are really worth it and can still be used later if you decide to buy a better player.

/edit: I don't have the schematics of a DCD-695, but I have those of the 1015, 1450AR and 1550AR, so my experience is based on those machines.
 

OneyedK

Member
2007-10-02 9:57 pm
Tolu said:
As you can see at the first picture there are no opamps for output stage or am I totally wrong!?

I think they go more or less directly from the opamp output of the PCM61P (pin 9) to the RCAs.

Ai, that's not so good. PCM61P has a current output on pin 13, wich is used in the Denon's I know. If pin 9 is used, an internal OpAmp of the PCM61P is used for I/V conversion. (specs seem pretty good)

You could create your own I/V-stage, but I think that would be a bit overkill for a 695.

Just take the signal at pin 9 and couple it directly via a good capacitor to the RCA outputs. (make sure to remove all components that could harm the signal)