Marantz CD63 & CD67 mods list

I have remove the 5v jumper wire and added 3 extra 5v regulator to the DAC. The output pin of the regulator is inserted to the hole left by the jumper wire while the input and ground pin are connected to C813 above the board using a pair of twisted wire.

All is working well except when the amp is turn to 9 o'clock there is background noise which was not there before the mod. Did I accidentally created a ground loop by connecting the input ground to C813?
 
While we are a little off topic, I did some tidying up in my CD960 yesterday!! :)

Changed some servo decoupling caps from Cerefine to ZA, added a spare super reg to the HF area and generally tidied up. Everything seems a bit happier now which is good. For some reason previously, it didn't want to read a disk for the 1st 15 seconds from switch on but now its fine.

Counted up 8 SPowers, 2 QPowers, 2 Super regs and 4 Salas Shunts, a C2 clock and a home build clock for the Servo, and 294,000uF in smoothers run from 5 trans formers plus the original!! lol

It sounds "nice"................. :)
 
To get things back on topic again... :D

Here's my new DOS!
 

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This is the new version, designed by Steve (stvnharr) with Complementary Feedback Pairs in the input stage and current sink in the output stage. Please note the large output caps in the background :D. They are 15uF Obbligato Premium Gold.

First listening impressions (the solder has barely cooled down...): the highs are a bit grainy, which I consider normal with fresh Rel-Cap tin-foil caps in the filter, but the low-end is more controlled and timing is better. Time will bring more audio-nirvana...

Ray

Shot with my new Canon EOS 60D with EF-S 17-55mm f/2.8 IS USM for those who are interested :cool: at 40mm, 1 sec, ISO1600, f/11, no flash.
 
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Harsh ?? I will wait for the third board then, w/o CFP DOS for highs and w CFP for bass please!
15µF won't "slow" top end ? I've had a look at the phase shift and had nightmares after I realized the shift goes far further than the cutoff point, terrible. But will I be able to notice the phase shift? Don't know.

No, the only risk with a too small output cap is that the low-end will fall off. With 15uF, even the phase-shift is minimal :D.

Don't get me wrong, having a high-end that's a bit rough is normal in the beginning, when all the parts are new. Especially tin-foil caps can sound grainy at first, as I discovered with my speaker cross-overs. It has nothing to do with the DOS-circuit. You must know that by now! It will clear up in a few weeks. Tin-foils usually have a very defined and clear sound.

Haha

The one thing that has put me off is fitting all those nice large silver mica etc to the new one. I may find it easier implementing the CFP to mine.

Do you find the CFP worthwhile?

Brent

First impressions are positive, apart from the slight high-end grain that is. Bass seems more controlled and overall the music sounds more precise, better timing it seems. The final judgement has to wait, until it has run-in properly, but I don't expect there will be any negative side effects ;).

The CPF-board is easier to populate, so that shouldn't be an excuse :). But you may want to reconsider those silver-mica's, this dielektricum has a piezo-effect and should be avoided in audio. Polystyrenes, PPS or decent MKP's are a good alternative.

See this PDF on 'Picking Capacitors'. There's a nice table in there.

Ray