ESS Saber DAC

[leo]

Sorry I've not been on for a while

Regarding the Buffalo, its very very good IMO, it sounds good as stock but with some mods things get very interesting, I'll update the thread soon theres some parts of the ciruit which responds extremely well to better regulation etc

BTW, if you decide to try one I'd seriously suggest you make sure its one with the upgraded comparator, mine originally had a LMV7239, these are too slow for 192k so I've changed it to LMV7219 which is a faster part.
It not only allows for 192k but seemed to greatly improve any spdif signal fed into it

[themystical]

Go on Leo...spill the beans!!!

[Will]

The wee beastie is on the radar in the future. I, along with the others who've posted would really like to know what uncle leo has been upto with his modding.

[leo]

Its mainly regulation so you may find it boring anyway

The VA socket is used to supply the onboard LM4562 only, the VD socket supplies the onboard 3.3v LDO regs which supplies the XO ,comparator, parts of the dac chip, controller and finally a 1.2v LDO reg for the Sabres core
This 3.3v is also supplying the non inverted inputs to the LM4562 which is used as a buffer for the Sabres left and right VREF pins.
The VREF is extremely important and the supply here has a lot of influence on the Sabres performance, even the quality of the VA supply for the LM4562 buffer has an influence on the sound

What I've been doing is playing about with regulation on various parts including for the IVY
Once I've finished I'll post some updates, theres more I want to try yet

[rickcr42]

"The VA socket is used to supply the onboard LM4562 only, the VD socket supplies the onboard 3.3v LDO regs which supplies the XO ,comparator, parts of the dac chip, controller and finally a 1.2v LDO reg for the Sabres core"

Not having read the entire thread are you "pre" regulating the V-Regs ?

Having a low ripple stabilised power supply feeding the final regulators means the final regulating stage has a lot less "cleaning up" to do and if you use a "main ps feed bus" in the +/- 12 VDC range you can feed the analog stage directly (you don't gain much by going to +/-15 VDC for opamp stges) or if your output stage is discrete +/- 28 VDC then for the low voltage stages "cast off" the ecess voltage (you NEVER want such a wide margin between a V-Regs input pin and output pin because it will be converted to heat and heat is the SS electonics worst enemy) by using cascaded CRC (or even better if you have the room CLC) filter stages to lower the voltage while even further reducing ripple.Look to make this filter @ double the mains line freq.so for instance if a 60 hz line then 120 hz

"This 3.3v is also supplying the non inverted inputs to the LM4562 which is used as a buffer for the Sabres left and right VREF pins.
The VREF is extremely important and the supply here has a lot of influence on the Sabres performance, even the quality of the VA supply for the LM4562 buffer has an influence on the sound"

OS Cons and WIMA RFI caps at the digital IC pins ,BGs/Elnas/Pannies and WIMA MKP at the analog IC pins

Use the right "type" for the job and remeber,the receiver chip has an ANALOG section so bypass accordingly

[leo]

Thanks Rick!

At the moment I use ALW super regs used as pregulation supplying the Buffalo's onboard LDO regs
Raw DC is from a supply using CLRC

The Sabres VREF is extremely picky, there is currently a pair of 1uf ceramics after the buffer next to the VREF pins, any caps higher in value used here makes the sound noticeably worse, film caps also sounded worse probably due to higher inductance, I think its one reason they use the buffer here so the other decoupling caps on that supply are isolated and the VREF pins only see the 1uf ceramics

What I'm hoping to try soon is some Paul Hynes shunt regulators.
I will be running the dac core separate, the onboard LM4562 will be removed and will have a pair of PH shunt regs feeding the left and right VREF

[Spirit]

O Mr Leo,

Any updates for us eager folks?

Will probably be a good six months before I can build one, (parents have bought a place pretty much at my bidding... mortgage is fun), but I'm awful curious to hear [some more] of your thoughts.

With the analogue out of my x-meridian [and most other decent soundcards these days - esp when modded and amped properly] being so good.... I'm wondering if this will be the dac to give an appreciable peformance increase.

Cheers
Phil

[leo]

Soon as the new regs arrive and after I've fitted them to the Buffalo I'll be posting updates, the regs have to be built by hand and tested

[Spirit]

Heh.

Cheers mate

[minivan]

hey leo, is that the new regs from twisted pear?
the buffalo is so good, bought the kits b4 they put the price up .i am enjoying my buffalo now that all my other 3 dac are on the sideline.

[leo]

No, these regs are from Paul Hynes , rather than using a regulated psu like the ones from TP which supply all the Buffalo's onboard LDO regs I'm going to be replacing those LDO regs with discrete ones.

[leo]

Heres a pic with the Paul Hynes shunt regulators fitted

[minivan]

how does it sound in comparison? can u please go into more detail on how to mod this thing and where to get those shunt regulator?
thanks

[leo]

Dec 12, 2008 11:24:11 GMT minivan said:

how does it sound in comparison? can u please go into more detail on how to mod this thing and where to get those shunt regulator?
thanks

Regs are from here www.paulhynesdesign.com/page2.html
Some of the regs are not shown on the site, I think they are new

Heres what I fitted

1 x Z1A-3v3 positive shunt regulator which supplies main 3.3v and onboard Crystek 80mhz XO

1 x PR3G-1v2 positive series regulator supplying Sabres core and VDD1.2v

2 x Z1703v3 50mA positive shunt regulator supplying the Sabres left and right AVCC (VREF)

1 x Z1A-15 150mA positive shunt regulator set to 150mA supplying the +15v of the IVY I/V stage

1 x Z1N-15 150mA negative shunt regulator set to 150mA supplying the -15v of the IVY I/V stage


I personally am very pleased with the results, they needed a few days to run in but the improvements are more than noticeable

[Will]

Looks like the ES9008 chip has been superseded already.


http://www.esstech.com./index.php?p=products_DAC

Would sir like 32 bits?

It appears that the guys at Twisted Pear have these already, and are in the throws of making the new 'Buffalo'

[leo]

Miguels determined to ruin the the best spec chip on the market
What about if I gut out the Paul Hynes regs and use valve regulation instead

[PinkFloyd]

Jan 7, 2009 3:14:36 GMT mrarroyo said:

Jan 7, 2009 2:21:11 GMT leo said:

Miguels determined to ruin the the best spec chip on the market
What about if I gut out the Paul Hynes regs and use valve regulation instead

Maybe if you use petrified wood to build the case with. ;D

"wood" is Good but "log" is better.... it's more dense you see, for higher highs and lower lows....



A prime piece of LOG.

[leo]

Jan 7, 2009 3:14:36 GMT mrarroyo said:

Jan 7, 2009 2:21:11 GMT leo said:

Miguels determined to ruin the the best spec chip on the market
What about if I gut out the Paul Hynes regs and use valve regulation instead

Maybe if you use petrified wood to build the case with. ;D

Notice mines bolted to a chopping board for testing.
When I was looking at the output on a scope there was high frequency ringing which wasn't good, cut a long story short it was RF, I had to place an aluminum box over it when in use to help shield it out

[Deleted]

Leo
Was the RF from the DAC or the regulators ? Even 78xx have been know to oscillate around 3MHZ.
Alex

[leo]

Jan 7, 2009 11:18:09 GMT @sandyk said:

Leo
Was the RF from the DAC or the regulators ? Even 78xx have been know to oscillate around 3MHZ.
Alex

The cable connecting Dac and output stage was picking it up, it did this with standard regs too

Even though I used short runs of balanced screened cable it was sensitive, the IVY don't like the HF garbage injected into the feedback

[Deleted]

Leo
Is it external R.F. ?
Alex

[PinkFloyd]

Leo...... house that DAC in a nice piece of LOG and you can rename it the CABER DAC

[leo]

Jan 7, 2009 11:29:53 GMT @sandyk said:

Leo
Is it external R.F. ?
Alex

Alex,

Yes, it gets pretty bad around here

Leo

[leo]

Jan 7, 2009 12:47:17 GMT PinkFloyd said:

Leo...... house that DAC in a nice piece of LOG and you can rename it the CABER DAC

by the look on that blokes face he's already housed something in there and got a few splinters ;D

[rickcr42]

Maybe if you use petrified wood to build the case with.

Hell yes !

Be a good excuse to get that diamond blade wet saw you used once for a bathroom tile job out of the garage