Steinmusic cdm12.1

[Brownlow]

Hi ,

Has anyone had any experience of this kit. I am very interested in building this as it would be a big step into the Digital arena for me. As I would like to build a very decent sounding machine, I thought this might be a nice project before taking on something like the CD-PRO2.

Would really appreciate a response on this one.

Many Thanks.

Brownlow

[Peter Daniel]

What's the difference between CDM 12 and CD-Pro2? Pricewise they seem to be similar.

[till]

one is metal, one is plastic, electronic is same quality level, one is for robot loading / top load, the other for manual load/ front load/ consumer elektronics

[Cobra2]

Hi!
I have purchased the CDM 12, digital out (only), and remote-controlled.
I chose it over the "Pro" because of the drawer-mecanism.
As I already have a turntable, I did not want another top-loader.
Time will show what it is good for, -if (hopefull) it can replace my Sonic Frontiers SFT-1 drive...

Arne K
NORWAY

And I have the shematics...e-mail me or SteinMusic for a copy.

[mhuber]

Hi Brownlow,

Originally posted by Brownlow
Has anyone had any experience of this kit. I am very interested in building this as it would be a big step into the Digital arena for me.

I have built a prototype CD player using this drive:



Works like a champ but I still prefer vinyl over polycarbonate

I use the DF1704/PCM1704 combo. The low jitter clock (thanks Guido!) is positioned next to the DACs and is feed back to the drive. The CDM12 drive electronics are on an large old style pcb which makes modification to the circuit simple.

I do the I/U conversion by use of a simple 22R resistor. The output stage consists of a step up transformer followed by a single tube stage and an 1:1 output transformer (picture shows an older version with different output stage). My $2000 commercial CD player has not spun a single CD since I first listened to this mess of parts.

Manfred

[Brownlow]

Manfred,

That is some serious stuff you've got there...What DACs are you using (or maybe the real question is, what DACs are good)?

We know good chips cost money but this would give me an idea as to what I will need.

I thought it was time that I had a decent CD player. From what I've read so far this looks to be like some good kit.

Thanks for all contributions as usual, what would I do without this forum?!

Cheers.

Brownlow

[Peter Daniel]

Originally posted by Brownlow
Manfred,

What DACs are you using (or maybe the real question is, what DACs are good)?

I think he already stated that he's using BB PCM1704 DACs, which is what I'm using too. Manfred, were you not tempted to go non oversampling route?

I would be more interested in a question, what output transformers are you using? Bernhard praised it so much, that your setup is almost legendary in here.

[mhuber]

Brownlow,

Originally posted by Brownlow
What DACs are you using (or maybe the real question is, what DACs are good)?

As I already have said I use the Burr-Brown (now TI) DF1704 digital filter and a pair of BB PCM1704 DACs. You may want to got to Google and type in PCM1704. You will have no Problem finding the data sheet and many comments on this chip.

Manfred

[mhuber]

Hi Peter,

Manfred, were you not tempted to go non oversampling route?

From time to time I feel tempted to try non oversampling by reading glowing reports on the net. Self-flagellation helps with this kind of heretical thoughts! I guess I'm too much of an engineer to throw away all I have learnt about digital signal processing. Don't get me wrong folks, I'm not saying that non oversampling DACs cannot sound good but it's simply not my cup of tea.

I would be more interested in a question, what output transformers are you using?

The analog part looks like this: 22R resistor for I/U conversion, Sowter 8347 1:18.7 step up transformer, DL91 directly heated pentode connected as pseudo triode driving a Lundahl LL1635 transformer (www.lundahl.se). The LL1635 originally is an interstage transformer but I use it at the output. The tube has a plate resistance of about 3K to which the LL1635 adds about 2K of copper resistance giving a total output impedance of around 5K. Some may consider 5K to be too high but it works fine for me. This may be different if one has to drive long high capacitance interconnects.

I use a shunt regulator to generate the plate voltage (only 70V) for the DL91s. The filaments of the DL91s are heated by current sources and the bias voltage for the tube is coming from a lithium cell.

There is no analog reconstruction filter. The 8 times oversampling filter shifts digital artefacts up to about 350kHz and the signal transformers do a good job attenuating the junk up there.

Bernhard praised it so much, that your setup is almost legendary in here.

He's too kind but I also have to give credit to my friends Thomas Mayer and Guido Tent. They provided some of the essential ingredents (i.e.concepts). All I had to do was cooking the meal.

Manfred

[dice45]

Hallo Manfred!
welcome back

... an 1:1 output transformer (picture shows an older version with different output stage).

before i found that line, i thot, heck, can a digital camera have such heavy THD?

Uhhm, semantic correction, i am not kind, i am the same kind of monster.

Guido Tent also is around here now and then. Guido? You are out there?
I know Thomas Mayer's implemenation and must say, i am impressed, he is crazier than me, his digital setup comes close to the insane TT design of my diploma thesis; considering it is merely digital, it vastly outperforms it, and it exists and sounds simply terrific.

But your setup is more to my personal sonic taste and it has a fine balance of effort vs sonics. A gorgeous balance.
Thats why i am raving, anyone can do it for $5000, a master who does it for $50.
I chose numbers arbitrary and i am exaggerating to illustrate my point.
I am convinced, planet10 will let you use his frugalphile(tm) label with out license fees , just observing your choice of CD drive and tube