DIY tube cd player ?

[colbgrr]

This is another newbie post, and bear with me since I have virtually no knowledge of the subject I wish to discuss. Has anyone built there own CD player out of only-highest quality components so that they don't have to buy a high-end player and then mod it later. I'd like to build a tube player from scratch or a kit. I also have a general question about audio sound quality concerning tubes vs solid state and digital. Is the tube sound remarkable for any particular reason? I'd love to be schooled in this, as I'm sure there are many on this site who could do so.

Thanks a mill

[ErikdeBest]

There sure are people who build their own CD-player, some of the results are posted at this site.

I understand you are a newbie, if true, I wouldn't recomend you to build a whole CD-player. You could start with a DAC, which can be build from scratch or from a kit. Give a look at www.dddac.de, search for the TDA1543 DAC. This is simple...from here on things start to get complicated...

Here is a link to a tubed IV stage, for the TDA1541A
Thorsten's Valve Output Stage with TDA1541DAC

Give a look around, you sure will find (to much) information on this forum.

Erik

[beamnet]

the easyest way to go is to buy a GOOD cd player: no high end blabla unit, but a heavy, old marantz or philips player.

It takes about a hand full of compnents to modify the IV (this is the part that translates the minute CURRENT (i) from the DAC into output VOLTAGE (v) into a tube output.

This has been wonderfull and cheap for me. Spent about $20 on an old player and another $40 on components...

[ErikdeBest]

I couldn't agree more with Beamnet - to make or modify some electronics is far more easier than all the mechanics involved with a CD transport.

[beamnet]

And... i personally believe in science, i do not believe in god, allah or audiophiles

Before the DAC, a cd player is a cd player (basic quality provided)
Digital is digital.

Just a means to get little dents in a reflective layer into 0' an 1's. any failure there is eliminated by the checksum and big failures only occur in really bad players.

focus yourself on a good dac chip and a descent IV. Personally, the gain in quality by modifying the ss output was a lot bigger vthan the gain from midified ss to tubes. First get those crap capacitors and cheap opamps out of the way....


bas

[planet10]

Originally posted by beamnet
a cd player is a cd player (basic quality provided)
Digital is digital....Just a means to get little dents in a reflective layer into 0' an 1's

Unfortunately not nearly that simple...a couple quotes from an interview with Julian Vereker...

... the signal that comes off the disc is actually basically an 11 Mhz radio frequency....it is not just a simple pulse stream as you would imagine.... It's not like a stream oh ones and noughts at all. Yeah, as you say far more like ananlog.

If you have a laser busily reading the disc, there's obviosly going to be quite a bit of reflection and scattering of the signal, and if it's reflected off anything back in phase with the signal that's going on it just mucks the signal up.

dave

[beamnet]

if cd players would make regular mictakes reading. Then how do cdroms work? If i'd type a simple asci text and copy it on a cd, the words don't change if i read it again..

Bas

[planet10]

Originally posted by beamnet
if cd players would make regular mictakes reading. Then how do cdroms work? If i'd type a simple asci text and copy it on a cd, the words don't change if i read it again..

A CD-ROM can try as many times as it needs to get all the info... a CD-player had to play in real-time. When i ripped my CD collection to my hard drive with error correction, on average it took well over the playing time to get everything off the disk... a CD player can only guess when it has trouble.

This is one of the reasons that computer as transport has such large potential... now if we'd see some good USB DAC projects....

dave

[beamnet]

well, let's say a cd player misreads one byte out of every 1000

that means 44.1 erros per second

that means, if it would read twenty seconds anew, it would have to read about a thousand errors. That means he still misses one.

one byte error in one million is fatal for a pc

the entire inside of a pc looks horrible when viewed on a scope, yet it works perfectly (in most cases)


If you had some figures on how often a cd player misses a bit, then you could calculate wther that would be beyond the noise floor of your setup

Bas

[planet10]

Originally posted by beamnet
If you had some figures on how often a cd player misses a bit, then you could calculate wther that would be beyond the noise floor of your setup

From my ripping CDs experience (relying on memory & an incomplete sample set -- i didn't watch the RIP on all of them) it was typically at least looking at half the bits twice, and as much as having to read each bit 4 x. On a multi-speed CD-ROM this isn't a huge hardship, but on a 1x CD-Player it means it is potentially making lots of mistakes. Unlike a computer a CD-player doesn't have the time to be perfect.

dave