Secret project (Svart AD/DA converters)

So investigating the DAC heat, it's because the SPDIF receiver boots up in 192K mode first, which then sets the PCM1794 chips into their highest current consumption setup, which is almost 150mW more power dissipation than the base consumption. Since I primarily use the converters at 44.1K(for mixdown without dither), they subsequently drop to their lowest current consumption and only about 250mW of power dissipation.

So nothing inherently wrong here, just overlooked when reading the receiver's datasheet.

It's partly true.

The heat isn't what makes an oscillator work better, but heating it makes it harder for changes in ambient temperature to affect it.  Changes in temp, even very small ones, can cause an effect called "wandering" where the oscillator will change frequency.  Sometimes it's fast, sometimes it's slow, sometimes it's a lot, sometimes just a little. 

There is a specific part called a OCXO, short for "Oven Controlled Crystal Oscillator" (or sometimes Oven Compensated Oscillator), which literally has a heating element inside of a small metal box with the oscillator.  These heat up and stay at that temp for crystal stability.  They also cost lots of money.

Without the heating feedback control, you'll still get variations in ambient temperature, so the theory is a good guess, but probably shows little benefit in implementation. 

There are also TCXO, Temperature Compensated Crystal Oscillator, which has internal circuitry that is used to bias the crystal element differently over the temperature range so that the output signal is relatively stable.

I use a TCXO but it's a hybrid DPLL which not only uses an internal TCXO but has signal feedback like a standard PLL which keeps it very stable.  5ppM stable..  Almost as good as a OCXO.

Welcome, b1 - I believe they're going for $800 for the pair or $400 separately. Check this link out too - www.realgearonline.com/post/57267/thread
Top of the second page I give my thoughts on the DA.

Just a quick note to reiterate this that I posted above:

I've been getting a LOT of private messages about AD/DA questions that are ALL answered in this thread and in the other threads. I understand that the information has been somewhat spread out too much, but I'm not going to be able to keep track of who asks what over PM, so PLEASE ask your questions here if you need to ask a specific question.

Please check these threads for any and all information you might want to know:

The "list" and pricing specifics:
realgearonline.com/thread/2297/audio-converter-buyer-list

3rd party review of the prototype unit:
www.realgearonline.com/thread/3204/svart-box-prototype-landed

The design and technical information thread:
www.realgearonline.com/thread/2161/secret-project-svart-ad-converters

svart do you want me to open the buyers list thread again?

i know it's probably somewhere in this 29 page thread, but does this unit have optical spdif output or just coax?

i know there are coax to optical converters out there, are these any good or do they do weird stuff to the signal? going to be getting a motu 16a and don't have the spdif coax option on it.

Svart,

is it still possible, to get your unit with one or the other converters and to add ( either you or diy) the other later ?

Thx !

thanks all understood !

it's on it's way from Minnesota to my apt in BK :-) Should've arrived today, but USPS is dumb and didn't put it in a truck until this morning even tho Dan dropped it off with them monday.

Svart, I'd be interested in what you think of some of the stuff on this site:

www.audio-gd.com/Pro/Headphoneamp/FUN/FUNEN.htm

I wondered if you would find anything there that would cut down on your production costs in future builds.