Marantz CD63KI - XO clock in, sound bad...

[Zombie]

Hello!
I have a heavily modded Marantz CD63 Mk II KIS, I have done the following:
- no output caps, mute transistors etc. in the output stage.
- no HDAM
- the first clock mod from www.acoustica.org.uk
- I use 2134 opamps, bypassed with 0,1uF polyprops at the pins
- Shottky diodes in the rectifier section (not bypassed with 0,1uF ceramics)
- bypassed the second opamp (filter section)
- matched the resistors on the first opamp input within 0,1% (recommended)
- the player and transport full with bitumen and blue-tak
- shorted the protective resistors on the +/-12V
In short, the signal goes straight from the first opamp after the DAC to the phono contacts and the out to my system.

Yesterday I installed an XO clock into the player and I can hear an improvement in detail and resolution. The stereo image is also more exact and the bass is a bit better.
Still I am not satisfied with the result, the sound is/has become "shrill". I am still remembering the soft, warm sound I got when I removed only the output caps...
I still have the 0,1uF ceramic cap on the DAC pins, as described in the first clock mod.
The wires from the XO clock to the board is about 1 cm and is single copper wire. The power supply comes from the output pin of the 12V regulator as LCAudio instructs. That wire is a multiple copper wire inside. I also have a separate XOClock power supply, but I haven't installed it yet (is it any good, btw?).
What are your suggestions? Go back to HDAM/2nd opamp-filter? Go further and install the separate power supply, clean up the 5V rail, install coax cables, improve the power supply? Or have I done smth wrong?
Looking forward to your informed advice and suggestions...

[Audiofanatic]

Hi this is what I get when I enter, www.acoustica.orgNo web site is configured at this address.

Audiofanatic

[Zombie]

www.acoustica.org.uk it is, sorry...

[Elso Kwak]

Hi Zombie,
Did you connect the clock to the digital supply? Connecting the clock-circuit to the analog supply will detoriate the sound seriously! I my experience a separate transformer is not necessary for the clock circuit.

[Zombie]

Hello!
I connected it to the output leg of Q801 as LCAudio instructs.
It's the one just behind the digital rca output on the CD63.
Mvh
Tom aka Zombie

[TheMyxin]

[QUOTE]Originally posted by Zombie
[B]Hello!
I have a heavily modded Marantz CD63 Mk II KIS, I have done the following:
- no output caps, mute transistors etc. in the output stage.
- no HDAM
- the first clock mod from www.acoustica.org.uk
- I use 2134 opamps, bypassed with 0,1uF polyprops at the pins


Hello Zombie
I have also a modified Marantz CD63KI.
Some Parts i have made self, some was
in the past modfied from a proff german
modifier from my hifi-vendor.

In my case i have not the XO-Clock-Modul but the same Quarz
(the HyQ-Quarz with 5 ppm) instead
of the ordinary Quarz and i have
removed the two small caps CD02/CD03
beside the quarz (This was a suggestion from the modifier later)
and this do the job well.
In my Marantz the HDAMs are also bypassed and there are not elco-caps
in the signal path at the output and
the mute-transistors are also bypassed.
The OPs are the BB OP2134 and instead
the cerfines there are the Roederstein
ROE1830 (Hard to find i know) foil caps.
in the supply part i have Panasonic
FCs in the analog part. I have self also
replaced on the 12Voltage Supply the
elnas with Panasonic FC (C804/C803 with
3330uf/25V, C814 1000uf/25V, C813 4700uf/16V, C815 3330uf/10V

- S

[ergo]

Zombie,

you may want to try either to leave the HDAM circuit in the signal path or do as I did and use only the output JFET pair (2SJ74, 2SK170) of HDAM to buffer the first opamp stage from output.

I tried the variation also where the signal went straight to output plugs after the first opamp - I also found the sound shrill and especially with music material "that has a lot going on at one time"... The cure was the buffer I mentioned before. I guess the opamp has trouble filtering and driving the cable all at once, even though it is a good opamp.

Ergo

[Zombie]

Hello Ergo!
My post is a bit old now and I read through your recommendations in another post. I have put the HDAM back, but bypassed the second opamp. Like you said, the sound is better.
I have also put in separate regulators for the clock, analogue and digital sections of the DAC, all taken from the 5V feed.
It sounds pretty good now...
The next steps would be to put in the LCAudio PSU (+ a regulator) and use it for either the analogue part or the DAC. To clean up the 5V rail would also be good...

Ergo, it would be extremely interesting to compare my CD63 to any of your modded machines.
The mods have developed into an interest (some say obsession) to see how much can be squeezed out of this poor old CD63.
I haven't finished with it yet

Cheers,
Tom

[ALW]

Tom,

Do you have this: -

http://www.alw.audio.dsl.pipex.com/D...ice_Manual.pdf

The second op-amp is part of the post-DAC filter, and should not be bypassed.

Better to change the filter caps to better types (polystyrene / PPS) and maybe modify the filter characteristics slightly for better response.

I would definitely install a seperate supply for the clock, the 5V supply in a CD63 is VERY noisy, and is modulated heavily by the mechanism currents.

The DAC inverter / oscillator gate should have it's own reg too for the same reason - even when using an external clock the PSU noise adds jitter to the clock when it passes through the DAC's internal inverter.

Another big plus is leaving the HDAM stages in place, but giving them a far better PSU feed than the poor 7812 / 7912's used currently.

Andy.

[Zombie]

Thanx ALW, I've got it. Can't do much without it, can you?

Better to change the filter caps to better types (polystyrene / PPS) and maybe modify the filter characteristics slightly for better response.

What do you mean? To put a 120p cap instead of 100p? Or do you have any bigger changes in mind?
Would be very interesting to know and try out...

What do you guys think about making drop-in regulators with LM317/337 on veroboard in the place of the 7812/7912?
And to use the recently discussed (LT1763?) reg as a drop-in for the 5V rail?

Cheers
Tom