Early CD Player Specifications / 14 bit vs 16 bit DAC

A while back I got a Hitachi DA-1000, one of the first CD Players put into production, and the basis for a good number of the earliest CDP designs.

http://theartofsound.net/forum/showt...1168#post41168

What is intriguing me, and what I've not been able to find via Google, Wikipedia etc, is how the early 14 bit DACs work. Wikipedia says that Philips developed a 4 x oversampling process which gave 16 bit performance from a 14 bit DAC. Is that the difference, and what exactly does that mean?

I have been pleased with the performance of my DA-1000 but haven't had the chance to properly put it head to head with my Sony CDP. I expected sound like some of the very poor budget players / portables from the early 90's, but it's nothing like that, so must be doing something right.

I'd be interested in hearing what those of you with experience of these early machines have to say :)

From a subjective basis, the early machines suffered on their analogue outputs, as well as spraying loads of ultra-sonic and RF frequency mush into the system, either down the signal leads, or the screen of the interconnects.

14 bit means a reduced noise floor (FM radio is 13 bit and this gives around 65db dynamic range I understand) and the way I heard it was "dirty" sounding analogue tape hiss and exaggerated Dolby A tracking errors on early CD transfers (the fadeouts on Trick Of The Tail by Genesis and a track or two on David Bowie's Low in original CD issues). These early machines didn't do reverb very well either, either because of the DAC's/digital filters, or shortcomings in their analogue circuits..

The early Sony CDP 101 was basically good, but with a "dead" kind of presentations, whereas the early Philips and Marantz concoctions just gave me a headache, pure and simple. My first CD player was a Meridian MCD Pro, which is still working (just about) and this was the first machine to allow me to listen for long periods.

How early do you want me to go? By the late eighties, there were some classic machines coming out and many of the best of these are still amazing. All that's happened since is that the technology has got cheaper and the transports are two a penny nowadays. A Cambridge CD player at £300 is probably as good in performance (bench tests and sound) as many late eighties top end players I suspect, even if it's cheaply made in China for pennies in real terms.

From The Grave

Nice one Chris. It would be interesting to see what the latest influx of tech-heads have to say about the way the early 14bit CD Players worked...

That's what I thought - AoS has moved on a bit since May 2009!

See here.. http://www.dutchaudioclassics.nl/the...igital_filter/

The TDA1540 is a 14-bit DAC, combined with a 4x oversampling digital filter and noise shaper allowed 16-bit equivalent performance, with the added benefit of allowing more gentle 3rd order analogue filtering.

I had a Marantz 14-bit player (CD45 SE?) that really sounded pretty nice, certainly compared to the Sony CDP-101 that preceded it.

Cheers,
Alex

Andre,

How did you do that? More importantly, why did you do that? ;)

without an appropriate high-order analogue filter you will get aliased images in the audio band. I've never heard an unfiltered DAC, but it is definately putting something into the output that doesn't belong, and that can't be a good thing....


Alex