I bought a Marantz CD63 a few weeks back, basically because I've got a million CDs and nowt to play them on apart from a Logitech Squeezebox.
So I got this thing from eBay for £40, and being a bit of a hifi nerd, opened it. Lots of through hole components
Seems there's a lot of online stuff about this player, including a full set of circuit diagrams. Sooo..
In the last few weeks I've basically removed a load of it. The proprietry Marantz HDAM, which after a lot of study appears to be a pretty well thought out buffer amplifier, but largely unnecessary if the stages before are optimised. The mute circuits, which don't really appear to do anything.
I've been through the analogue stages, removing EVERY passive component, replacing with hand matched (L to R) components within 0.1%, and changing the remaining low pass filter and buffer op amps with dedicated professional audio replacements.
I've re-jigged the DAC clock in order to reduce jitter, as best you can with this particular design.
To be honest, it sounded pretty good 'out of the box'. I was pretty surprised at the changes the mods have brought about. At first I was quite underwhelmed, but on further listening, the only way I can describe it is 'analogue'. The HF mush that seems to be there with all CD playback has gone. Treble seemed to be recessed at first, but all that has happened is it is more defined. I am able to distinguish how the stick hit the cymbal rather than just assuming that 'tsshhh' is a cymbal of some sort.
Bass - subtle. I am able to compare with a lossless digital copy (Squeezebox) and whilst that sounds great, critical listening reveals bass guitar that sounds great on the Squeeze, but the new CD, the leading edge of those plucks sounds subtly more defined, more'real' rather than soft, and that buzz against frets is more 'in the room' and less detatched.
Yes, I'm pleased. I have more to do, and have just finished a low noise regulator board today to pop in to separate the analogue power stages out. Will give my ears a chance to get used to where this is now, then make the mod.
Sorry to bore most of you, but I suspect there's one or two here who like this sort of stuff without being as unblinkingly evangelistic as some of the folk on the Audio forums!
"Two very small men cutting steps in the roof of the world"