Marantz CD63 & CD67 mods list

[Fidelity Audio]

Originally posted by SimontY
Behold, the alien craft has landed!!! Can it breathe our air??

Yes it can but only for 3 hours. I need to fit a fluffle valve to it and supply it with methane (mainly from my own blow hole)

[SimontY]

lol

[6h5c]

Wow, cool job Brent!

Will order myself some thin coax this week
What kind did you use, and did you terminate it?

Ray.

[Fidelity Audio]

Originally posted by 6h5c
Wow, cool job Brent!

Will order myself some thin coax this week
What kind did you use, and did you terminate it?

Ray.

Here is the manufacturer

http://www.hubersuhner.com/hs-rf-cables

Its 50 ohm +/- 2 ohm.

We have it here at work, it's for connecting £20000+ calibrators together that read ohms and current down to 8.5 decimal places.
So I thought it would be ok.

They are soldered direct, If I need to take the pcb out I will just undo the two screws on the mech that hold the pcb in place.

[Fidelity Audio]

Ray do you live anywhere near Eindhoven.

If so FLUKE will have thousands of these. They scrap perfectly good cables like this all the time.

Well thats what they do in the UK.

[6h5c]

Originally posted by rowemeister
We have it here at work, it's for connecting £20000+ calibrators together that read ohms and current down to 8.5 decimal places.
So I thought it would be ok.

I suppose what's good enough for £20000+ calibrators is good enough for a CD63KI

They are soldered direct, If I need to take the pcb out I will just undo the two screws on the mech that hold the pcb in place.

So you didn't use any series/termination 50R resistors?

Ray do you live anywhere near Eindhoven.
If so FLUKE will have thousands of these. They scrap perfectly good cables like this all the time. Well thats what they do in the UK.

No, not very near. But I have a dump-store at 1/2 hr. drive from my place. It's worth to take a look and see what they've got. Maybe some nice MIL-spec coax

Ray.

[Fidelity Audio]

No Ray not on the SIDA and SICK lines.

I kept the 10PF cap and 390 ohm resistor on the DAC clock out for Decoder.

Is it really that necessary on such small runs? I'm not sure.

[6h5c]

I'm not sure either
I don't have a good scope to take a look at the waveform. But technically there could be reflections bouncing back and forward that interfere with the original waveform.

I've done some more tinkering with the passive filters, and did some more simulations. Here's a PDF with the latest i've come up with.

The circuit of the Butterworth filters matches that of the player's PCB, so it's easier to fit the components on the original board. Also the input impedance is much more constant compared to Thorsten's circuit. But I don't know at what impedance the DAC is most happy.
I made filters with various attenuation, because I still have to decide what buffer i'm going to use. Maybe the modified HDAM, or a Lundahl tranny, or a tubestage. Have to do some more experiments.

Regards,

Ray.

[Fidelity Audio]

Originally posted by 6h5c
I'm not sure either
I don't have a good scope to take a look at the waveform. But technically there could be reflections bouncing back and forward that interfere with the original waveform.

I've done some more tinkering with the passive filters, and did some more simulations. Here's a PDF with the latest i've come up with.

The circuit of the Butterworth filters matches that of the player's PCB, so it's easier to fit the components on the original board. Also the input impedance is much more constant compared to Thorsten's circuit. But I don't know at what impedance the DAC is most happy.
I made filters with various attenuation, because I still have to decide what buffer i'm going to use. Maybe the modified HDAM, or a Lundahl tranny, or a tubestage. Have to do some more experiments.

Regards,

Ray.

All I can report is that the sound is much better now.
I wasnt going to add anything extra in until I know better

[poynton]

Originally posted by 6h5c
I'm not sure either
I don't have a good scope to take a look at the waveform. But technically there could be reflections bouncing back and forward that interfere with the original waveform.

I've done some more tinkering with the passive filters, and did some more simulations. Here's a PDF with the latest i've come up with.

The circuit of the Butterworth filters matches that of the player's PCB, so it's easier to fit the components on the original board. Also the input impedance is much more constant compared to Thorsten's circuit. But I don't know at what impedance the DAC is most happy.
I made filters with various attenuation, because I still have to decide what buffer i'm going to use. Maybe the modified HDAM, or a Lundahl tranny, or a tubestage. Have to do some more experiments.

Regards,

Ray.

Ray - could you explain the figures please.

Attenuation dB, ? , attenuation at 20kHz

My turn to ask the silly question !

Andy