Marantz CD-75 MkII with cdm1 markII spdif from SA7220 and Philips dvd763 stock spdif on Ultramatch
JACQUES HIFI PAGES
The realm of CD TRANSPORTS
Marantz
CD-75 MkII with cdm1 markII spdif from SA7220 and Philips dvd763 stock spdif
on Ultramatch
Let's face it : differences between transports are very small. Don't expect night and day between ultra-high-end drive with Philips pro mechanism and huge separate power sections going into balanced spdif and a no-name DVD player with stock spdif cinch output. This is a least to my ears of course. You will always someone who greatly disagree but I wonder if they have done A/B tests ....I did and I found very wee differences requiring trained ears. I mean real A/B when you don't know which drive is playing. Let the good people from Philips explain us why :
As it is clearly explain here ---CD104 brochure--- , noise is a real problem with analog signals but not really for bits. It is easy for any chips to read 0 and 1 even with a lot of weird noises occuring. ( picture d ). Let's see the real life situation :
This is the usual trace I obtain
with stock spdif from Philips .
It's not that bad but as you can see problems are not what Philips predicted
: no excessive noise but a slope on a trace which is not really square .
Taking signals as strong
and as direct possible from the DSP chip ( usually SA7220 on Philips and CXD11something
on Sony ) usually gives squarer but noisier traces . Seems that Philips engineers
actually feared noise more than slope, unlike their brochure speech .
So I started experiment
with all CD players that were unused because of average DACs, in trying to find
a correlation between trace and tone.
See my page of test drive
on oscilloscope.
Here
are my 2 champions :
Don't ask me why, the Siemens on the top , which have nothing special neither on the circuit ( or is it so ? ) nor on the laser gives me the best results. He seems more airy on the vocals that seem to float between my speaker like the ghost of the singer coming back from the past. I really hear differences in this presence of the human being. Some people will swear by better basses on a given transport, but I never experienced such a difference. Maybe they were looking at a big drive. Once again, blindfold test is the only truth. I will also find bigger bass when my heavy and huge LDV Philips CDV486 is playing against this flimsy Siemens, but this feeling dissapear completely when I do a blindfold test. Remains the airy vocals of the Siemens I can tell everytime.
As you can see, nothing magical in the Siemens. Light Sony stuff everywhere. There was no spdif on this player but I was lucky that damned pin27 of the CXD1135 was available on the good side of the board ( yellow wire going to the scavenged output cinch ). Usually you have to do this acrobat work :
Here I tried wiring the pin27 on a similar Brandt brand CD player and it did not work. So I tried to put the pin56 ( DOTX enable H or L ) on H but sending it 2.65v instead of ground . Did not work. And full 5v put all the cd player in short circuit : I found out that the digital switch pin was grounded STOCK inside the chip . How can they do that ? With a ram program ? Deep mistery with this player . Anyway ,wiring directly the pin27 is a nightmare : I already broke 3 of them. So before you buy a Sony based CD player to make a transport out of it, better buy one which already has some kind of digital output. You will be sure the pin27 is connected to something you can solder.
Here on the Sony I love , it was easy. There was a beige painting on the point to be soldered. Unfortunately, the laser itself was VERY sensitive to interferences which are huge in the spdif signal : I had to put the yellow wire away from everything and isolate the group of grey wires coming out of the laser assembly . It still behave when cold, even after cleaning everything and working of the small servo settings. Eventually I found that the AC plug had a direction and it works better if you reverse blue and brown 220v...weird...Here the laser is a KSS240 and the DSP a CXD2500 which has DOTX on pin 60. Not as airy as the Siemens, but it has something of its own. Authority or something.
.
Same work on an Akai. Sony based CD players seem to sound better as transport than Philips. My Marantz CD75 mkII should be the best with its 100% metal mechanism and spdif taken directly from SA7220, but the lightweight Siemens is always better. Maybe there is something about light weight on the CD....as you can see the Siemens has a very light puck which applies only the necessary force on the CD not to wobble, but not more. If this is true, I wonder if the magnetic clampers you see on high end drives are not a big mistake. When possible, I usually take off one of the spring of Philips clamps.
Too bad for the Philips SACD DVD player on the top of this page...it was great to have full text but its sound as a drive was not that good and I hated the noise of the disc rotating at full speed anyytime. Old CD player , once you are past track one, turn very slowly with no rotating noises. Not very important for Prodigy records but crucial for Chopin Mazurkas.
This is my homemade CD player from empty computer box, CD Rom drive and chinese controler with remote. I managed to silent the rotating noise inside the box and the 19euros brand new ASUS DVD rom made a real good transport with buit-in digital output and the computer power feed. But there are hundred of Sony based CD player that can be bought for the same price and modded as transport with better result. So why bother.
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