Marantz CD63 & CD67 mods list

[ash_dac]

Hi,

http://www.grimmaudio.com/whitepaper...0converter.pdf

This seems to be a useful RF fix for a pdm dac (the CS4303).

Would it work with a pwm dac like the SM5872 ?

[avr300]

I was searching the threat for "8620" but I found no hits ?

Have any of you tried the AD8620 (and not written 'bout it). If so, how will you describe it?

Just wondering, before I order a pair of premounted browndogs.

/avr300

[6h5c]

Originally posted by SimontY
The -19.5v isn't right. I'm confused and I don't understand this complex psu arrangement.

The problem is around the 7918 regulator (Q851), it measures:
pin1 - 0
pin2 - -36
pin3 - -26

I don't think this is at all correct, lol!

Hi Simon,

The heater voltage is o.k. so that's one thing. But it should be at a DC offset of about -13V. That pin 3 voltage should be -18V with D852 shorted. Vftd is switched to the heater voltage by no less than seven transistors (Q852...854, QN01, 03, 04) and a 4V7 zener. This creates a power-on delay to make sure the heaters are up before Vftd and the display doesn't "fade-in" in an ugly manner. Maybe one of them has failed or has a dry joint? If you short the collector and emitter of Q852 there should be Vftd present on the heaters. Do you have Vftd present on pin 64 of the microcontroller?

Regards,

Ray.

[SimontY]

Hi Ray,

Thanks for your reply. It's late now, and I'll look again tomorrow. Still got her apart on the lounge table.

Cheers

[6h5c]

O.k., good luck. I'm going to hit the sack here too

Ray.

[Fidelity Audio]

Simon just in case you were not aware, the pins are different on a negative regulator to on a positive one.

i.e 7805 = pin 1 - i/p pin 2 - gnd pin 3 - o/p
7905 = pin 1 - gnd pin 2 - i/p pin 3 - o/p

Brent

[gy21]

Hello, this is my firts post here. I have been reading this thread for a while now and yesterday evening I modded my cd67se.

I removed the muting transistor and the dc blocking caps in the output stage. And damped the whole chasis.

When I turned the player on I heard things in my music collection I never heard before, really nice bass.

I will continu to mod my player with new opamps bypass hdam buffer and then I will see what's next.

Any way, thanks for sharing information on this.

[Fidelity Audio]

Originally posted by gy21
Hello, this is my firts post here. I have been reading this thread for a while now and yesterday evening I modded my cd67se.

I removed the muting transistor and the dc blocking caps in the output stage. And damped the whole chasis.

When I turned the player on I heard things in my music collection I never heard before, really nice bass.

I will continu to mod my player with new opamps bypass hdam buffer and then I will see what's next.

Any way, thanks for sharing information on this.

Glad to help mate, you are going to be very suprised by what this player can do.

[philpoole]

I was searching the threat for "8620" but I found no hits ?

Have any of you tried the AD8620 (and not written 'bout it). If so, how will you describe it?

Just wondering, before I order a pair of premounted browndogs.

/avr300

Hi,
Not sure if its too relevant, but I did upgrade a friends CD63 last year and as an experiment, I put in AD OP249 (SR 22v/uS GBP 4.7Mhz SetT 0.9uS). These were deliberately chosen as they were as close to spec as my BB2107 opamps as I could find, and they we're a lot cheaper (about £3 versus £15).

If I recall, I found the AD chips to be a bit more 'in your face' than my Burr Browns, which were far more laid back. They we're just as interesting, but had a very different sound.

It did reinforce for me that the AD chips tend to be more agressive BB equivalents. Both are maybe an acquired taste.



Still haven't had a chance to fix my CD63. Its been a week of work on the house and stuff. Ho hum. Really frustrated, because I want to get it fixed and then fit the bipolar output. So want to hear what it sounds like.

Cheers,
Phil

[SimontY]

Originally posted by rowemeister
Simon just in case you were not aware, the pins are different on a negative regulator to on a positive one.

i.e 7805 = pin 1 - i/p pin 2 - gnd pin 3 - o/p
7905 = pin 1 - gnd pin 2 - i/p pin 3 - o/p

Brent

Cheers man, I noticed this last night, just after I posted, hehe. My voltages are only slightly out then actually. Just a bit high on the output. I wonder if I somehow broke the regulator. But even so, it doesn't explain the pretty much zero DC voltage on the display power rail. My problem has been understanding the circuit to be honest. I did look at those transistor bits, and wonder if there's a problem there. I'll check all those joints carefully as my next task.

Transformer seems the most ovbious thing but all the leads seem to be soldered to something!!

For everyone's benefit is there some simple way of knowing which colour wire is which winding? Or is the only way to count them from one end to the other?