ESS Sabre Reference DAC (8-channel)

Hello Dustin,

Can you specify what needs to be done to set the Sabre into 9 bit mode? Currently Russ/Brians implementation contains this code relevant to this aspect:

if (QUANTIZER_SWITCH == 0)
{
setRegBits(14,3,3,TRUE_DIFFERENTIAL);
setRegBits(15,7,6,QUANT6);
setRegBits(15,5,4,QUANT6);
setRegBits(15,3,2,QUANT6);
setRegBits(15,1,0,QUANT6);
}
else
{
setRegBits(14,3,3,PSEUDO_DIFFERENTIAL);
setRegBits(15,7,6,QUANT9);
setRegBits(15,5,4,QUANT9);
setRegBits(15,3,2,QUANT9);
setRegBits(15,1,0,QUANT9);
}

However it seems to be insufficient to get it working properly in 9 bit mode - it produces an output that has way to few bits:

minus30db.jpg


Thanks for any help.
 
Review time!

I have been using mine now for about a fortnight or so. I just wanted to listen for a while to see how it worked and also then to compare to my CDP when I switched back.

It really does have incredible resolution - very clear defined soundstage - and my CDP is no slouch in this regard. It locks on no problem every time - although I couldn't get it to lock on to a signal from a USB>>S/PDIF convertor I have at the PC. I've since read that this converter has the worst jitter measurement ever seen!

It is "digital" sounding (as opposed to a NOS DAC eg) but in a good way. Things like transients are lightning fast, so drums and percussion sound great. So far it hasn't been in any way fatiguing at all - which is what sometimes happens when a product sounds like this at first. It has a really fullsome bass without any sloppiness and the aformentioned treble never sounds harsh or grainy. It does a lovely job on the vocals - when you get listening to really good well recorded vocals its hard to turn it off.

I have noticed quite a difference depending on the transport I use. My CDP sounds much more refined compared to using my crappy DVD recorder. Also I have put together a CDP based on a CDrom and it sounds quite a bit "warmer". So the sound you're getting ain't all about no jitter - the transport obviously matters quite a bit.

Is it a good buy - dead right!! Its probably not going to be something you can ever audition before you buy, but there seems to be a good demand :)D)for the DACs so if you really didn't like it you'd always flog it easily. I hope at some stage to bring it to a friends place and listen with different systems to see how it works with each.

For reference my set up is: Eastsound CD-E5 CDP, Buffalo/IVY combo, 24V Aikido valve preamp and EL84 PP power amp into Quad 57s.



Fran
 
Russ/Brian (or anyone else who knows)

First i want to give you both a thumbs up for the nice projects!!

If i want to use an external wordclock generator (of very good quality) with the buffalo dac what is the best way to do this? Is is just connecting the wires to d1 terminal? I guess the sabre has an internal pll?

And is there a way to turn the reclocking/asrc off? I intend to clock my sound card and the Buffalo that i intend to buy from the same clock master.
 
The Sabre doesn't need any external clocking. It has it's own ASRC which is supposed to outperform any other asrc and seems to provide excellent results.
I don't remember that you could switch it off.

Generating a clock from external may be useless and degrade performance.

You may want to use an SPDIF receiver with wordclock input. Check WM8804. After all, if you have no jitter at the input, given you choose a clock for the Sabre which is a multiple of the frequency you'll use, the ASRC will simply pass words...

I'm a bit skeptical, despite I work in pro audio where we nearly always use a master clock to clock everything. I noticed several A/D and D/A working best without it.
 
Headache routing the Sabre...
It has been very well though anyway... But each time I do some "serious" routing I end up half mad...

Things are going on. May I soon post a topic to request your advice on my routing, to get the best out of it? I go through the expense of 4 layers to look if performances can go a little bit further, so if I mess the layout... xD

All caps Oscons, c0g/np0 (I'm designing for studio and live events so I try to escape any microphonic effect).

Big ugly FairRite SMT beads (big, ugly, but 6.2 mOhms at DC. Is it usefull... I don't know :/ but as I want to give a try at Jung super regulators, I try to keep line impedance as low as possible).

Vsense and Ground sense on each power line: Avvcr, Avccl, Avddl, Avddr, Dvdd, Dvcc, Vclock.

No onboard PIC, nothing else in fact... Just what is needed for the chip and headers all around for everything.

The point is good layout, to try it with I/V stages, input stages, power stages... Heavy prototyping ^^

There's an oscilloscope (digital) with the screen broken but VGA port on ebay, 500Mhz 500Ms/s... It may help me (my "old" tektronix being half dead...).

Well nobody cares, sorry, I said I went half mad when routing xD
 
123Chris,

Well yes it can if you want to live with the defaults. As I remember in that case using it this way will only present a problem with the zero mute issue which people are talking about.

Look at the data sheet and if you can live with the defaults then it will work for you. Of course this means SPDIF is out. But you could hook up USB via say a PCM2706/7 or use a Crystal/Cirrus SPDIF or do an I2S thingy.

Thanks
Gordon