ESS Saber DAC

[jkeny]

Smoothing off highs without losing detail is a good thing AFAIK - the more analogue-like (in the best possible sense of that term) it sounds the better

[grottojones]

Sept 17, 2010 21:40:19 GMT leo said:

Any details for the traffo's? prices where from etc?

Bud Purvine at Onetics supplied my OPTs. I paid $130.00/pair plus shipping about 8 months ago. Prices may have changed.

Onetics has no web presence, but Bud can be reached at :
[e-mail]
Or by telephone: [phone] (USA)

Glad you gave the Slow filter a try and posted here. I can't say that is is more "accurate" than the Fast (or vice versa), but I can listen to it for far longer without digital ear burnout.

I really like the Buffalo II board too Leo. Props to Russ and Brian for doing a great job, addressing straight paint by number kit builders all the way to gonzo DIY tweekers in one product.

[leo]

Ok, have a pair of batteries running the AVCC L&R.
A couple of hours listening it sounds to me theres a piece from the high's and bass shaved off, the bass is a little more rounded, midrange is very sweet but I'm finding instruments and background sounds are shoved in together with the vocals , I'm not getting the separation between vocals and instruments I'm used to.
I'll stick with it a little longer, obviously this is all personal taste and the only way we know what we like is to try things out ourself , I'm going to go through more tracks I know well and see how it goes .
So far I like some things the batteries do but not others. It actually reminds me of the Peter Daniel based TDA1543 dac in some area's

[leo]

Sept 18, 2010 3:38:15 GMT grottojones said:

Sept 17, 2010 21:40:19 GMT leo said:

Any details for the traffo's? prices where from etc?

Bud Purvine at Onetics supplied my OPTs. I paid $130.00/pair plus shipping about 8 months ago. Prices may have changed.

Onetics has no web presence, but Bud can be reached at :
[e-mail]
Or by telephone: [phone] (USA)

Glad you gave the Slow filter a try and posted here. I can't say that is is more "accurate" than the Fast (or vice versa), but I can listen to it for far longer without digital ear burnout.

I really like the Buffalo II board too Leo. Props to Russ and Brian for doing a great job, addressing straight paint by number kit builders all the way to gonzo DIY tweekers in one product.

Thanks for the details, much appreciated

[jkeny]

Leo,
Just a few Qs (I'm sure you have these covered already)
- Your using A123 batteries?
- you have them connected directly to AVCC L/R pins i.e no caps or regs in between?
- your connecting wires are short?

[Deleted]

I'm finding instruments and background sounds are shoved in together with the vocals , I'm not getting the separation between vocals and instruments I'm used to.

Leo
That doesn't surprise me. Batteries are very good for giving a super quiet supply for Xtal oscillators etc. and will be better in some applications than others. I also have some concern about the typical terminal voltage of some batteries. Just because an input that uses say a nominal 3,3V, does that guarantee that the device works exactly the same at a higher than normally recommended supply rail ? Do we have any impedance vs. frequency charts for these Lithium batteries ? A good aftermarket regulator is still likely to have a VERY low supply impedance way past 500KHZ.
Could the batteries be used in conjunction with some added HF bypassing ?
I expect that you will also be using very short screened or twisted leads from the batteries to negate noise pick up.
Alex

[jkeny]

Alex,
I don't know if there is a imp V freq but here are the specs:
Nominal Capacity/Voltage: 2300mAh, 3.3V
Internal Impedance: 8mOhm
Internal Resistance: 10mOhm
Charging Current: 3A to 3.6V CCCV, 45 min
Fast Charge Current: 10A to 3.6V CCCV, 15 min
Max Cont. Discharge: 70A
Pulse Discharge 10sec: 120A

[leo]

Hi John.

1. Yes they are the A123 batteries, 26650

2. They go straight to the chip, there is the ceramic caps across the pins but nothing else , the value of the caps are pretty low , I can remove them but will probably be worse even with the shortest leads and track length's

3. The leads are short as possible, even the switch is sat on top of the dac so the leads are short.

The sound is far from terrible , its very sweet but for me so far I'm missing the separation, width and depth I'm used to

[Deleted]

Sept 27, 2010 22:34:38 GMT jkeny said:

Alex,
I don't know if there is a imp V freq but here are the specs:
Nominal Capacity/Voltage: 2300mAh, 3.3V
Internal Impedance: 8mOhm
Internal Resistance: 10mOhm
Charging Current: 3A to 3.6V CCCV, 45 min
Fast Charge Current: 10A to 3.6V CCCV, 15 min
Max Cont. Discharge: 70A
Pulse Discharge 10sec: 120A

John
These batteries were not designed for use in audio applications.
Leo's description of what he hears is very consistent with a much higher impedance at 100KHZ or more.
Alex

[jkeny]

Yep, as I thought, Leo, you have covered all the bases. I have somebody else who told me that the A123 batteries were far superior to the PH regs in this specific role, that of powering the AVCC. It may be down to personal preferences, I don't know - I'll contact him?

[jkeny]

Alex,
You could be right but just because they were not designed for audio doesn't mean that they aren't good at HF, purely by chance & not by design, of course! We won't know this for sure until somebody tests them at various frequencies. As I said I have somebody telling me that they easily beat out the PH regs in this role!

[leo]

I was actually going to try it on the XO first but went with the AVCC L&R because I always hear the effect there straight away.

At the end of the day its just personal taste , I'm willing to stick with it and try things out though if theres potential improvements to be had

[leo]

Sept 27, 2010 22:43:06 GMT jkeny said:

Alex,
You could be right but just because they were not designed for audio doesn't mean that they aren't good at HF, purely by chance & not by design, of course! We won't know this for sure until somebody tests them at various frequencies. As I said I have somebody telling me that they easily beat out the PH regs in this role!

Whats the impedance of the batteries higher than 1k? DC to 200 KHz for the Shunt regulator is less than 0.001

[jkeny]

I believe that 8mOhm is at 1KHz AC as this is the standard. Other than that I know of no measurements of impedance Vs freq

[Deleted]

Sept 27, 2010 23:01:22 GMT jkeny said:

I believe that 8mOhm is at 1KHz AC as this is the standard. Other than that I know of no measurements of impedance Vs freq

John
I am not trying to be a wet blanket, but what Leo reported hearing is exactly what I find with normal VREGs in comparison with the JLH that maintains a very low impedance way past 300KHZ (better in our versions ?) Separation, and pin point localisation suffers unless a very low Z is maintained past 100KHZ.
I would suggest that you experiment with supplemental bypassing right at the battery terminals, or the battery holder.
You may even be able to lift the concept up another notch ?
Regards
Alex

[jkeny]

Don't worry Alex!
Here's what the other guy had to say www.head-fi.org/forums/6581482-post935.html

I compared one of the A123 batteries that Jkeny uses to a number of other highly regarded regs, including a PFM flea, and the battery was easily superior to any of them. Kinda sad really as I've spent years building and designing discrete regs. I'm not sure what actually makes the batteries better, so I need to run some more tests, but I suspect it's either self noise from the regs or earth leakage currents causing problems. Good batteries solve these problems, but obviously charging/maintenance becomes the issue.

And more:

Better than the PH reg based supply. I've been using it to feed the analog supply of a Sabre DAC. The PH reg is in turn supplied by a very heavily filtered supply. The whole DAC is feed from a 1KVA isolation transformer, so as you can see, as mains based supplies go, this is pretty damn clean. I suspect that the reference on the PH reg is the limiting factor.

[Deleted]

Sept 27, 2010 23:23:52 GMT jkeny said:

Don't worry Alex!
Here's what the other guy had to say www.head-fi.org/forums/6581482-post935.html

I compared one of the A123 batteries that Jkeny uses to a number of other highly regarded regs, including a PFM flea, and the battery was easily superior to any of them. Kinda sad really as I've spent years building and designing discrete regs. I'm not sure what actually makes the batteries better, so I need to run some more tests, but I suspect it's either self noise from the regs or earth leakage currents causing problems. Good batteries solve these problems, but obviously charging/maintenance becomes the issue.

John
You would be wise not to ignore what Leo is saying. Not everybody hears things the same. Does this guy perchance also like using transformers at DAC outputs ? It is also possible that Leo uses far better amplification than many, that is capable of not only very low noise (Class A ) but also far better than average channel separation.
Unlike some other forums, we are on your side, and believe in the concept. Trust what your friends are telling you , enough to do further investigations. There are no Sy's or wakibaki's here.
We have Frans, but he is a pussycat in comparison to those other guys ! (Actually, having exchanged 100s of emails with him, he is a very nice guy)
Alex

[jkeny]

Don't worry Alex, I'm not kicking against Leo's report, I'm just reporting an alternative opinion. It's interesting to tease these things out, don't you think?

Alex, you forgot all the other names on various other fora that I've been banned from

[Deleted]

Sept 27, 2010 23:36:39 GMT jkeny said:

Don't worry Alex, I'm not kicking against Leo's report, I'm just reporting an alternative opinion. It's interesting to tease these things out, don't you think?

Alex, you forgot all the other names on various other fora that I've been banned from

'

John
Has the "cooling off" period in Computer Audiophile expired yet ?

Talking about CA, I would love to see our good friend (and nice guy) from The Neverlands express his views on PC Audio there.
C.C's replies would make very interesting reading ?
I wonder if the Chesky brothers would respond too.
Alex

[jkeny]

I don't know - does it automatically re-enable my account or do I have to appeal? Don't know if I'm bothered, I'm certainly not bothered about Head-fi.

I just found a paper on A123 cells @high Freq (100KHz) but I don't know how to read the graph - it's figure 7 pn page 21 from this pdf prod.sandia.gov/techlib/access-control.cgi/2008/085583.pdf

It says this on page 4 about the test:

The frequency range shall be large enough to encompass the anticipated
network response, and in this case corresponds to a range of 100 kHz to 10-4
Hz.
At least six different frequencies per decade shall be measured.

[leo]

Just proves you have to try this stuff out yourself , all part of the fun though eh

The batts are nice in a lot of area's, sweet especially the midrange, I'm just finding some of the instruments etc seem to be a little lost in the background. its more squashed together . Using the shunts fed from the PR3 series based regged supply instruments are more focused, more body , soundstage is wider .
I've done a lot of faffing about to get things how I like them using linear supplies so may have to fiddle some more with the batts , dunno yet. Both regs and batts sound clean though, certainly not bright and harsh at all

[Deleted]

Sept 28, 2010 0:09:26 GMT jkeny said:

I don't know - does it automatically re-enable my account or do I have to appeal? Don't know if I'm bothered, I'm certainly not bothered about Head-fi.

I just found a paper on A123 cells @high Freq (100KHz) but I don't know how to read the graph - it's figure 7 pn page 21 from this pdf prod.sandia.gov/techlib/access-control.cgi/2008/085583.pdf

It says this on page 4 about the test:

The frequency range shall be large enough to encompass the anticipated
network response, and in this case corresponds to a range of 100 kHz to 10-4
Hz.
At least six different frequencies per decade shall be measured.

John
I am also having difficulty interpreting the graph. Perhaps Frans can ?
Irrespective, Leo's results indicate that the impedance is increasing markedly at HF. As I said, the JLH goes WAY past 300KHZ. The PH regs go much higher again.Perhaps it is only obvious with gear that has far better than average channel separation ?
Let's leave out claims that separation of that order doesn't matter anyway !
Alex

[jkeny]

Alex, I'm not going to jump to conclusions on this yet. What is the impedance of the JLH & PH at the frequencies you are mentioning. What is the frequency range we should be interested in for the AVCC supply?

Leo, it might be worth trying to take out that final cap across the PS, just to see if it makes any diff? It's a ceramic cap, COG or other?

[Deleted]

Sept 28, 2010 0:33:09 GMT jkeny said:

Alex, I'm not going to jump to conclusions on this yet. What is the impedance of the JLH & PH at the frequencies you are mentioning. What is the frequency range we should be interested in for the AVCC supply?

Leo, it might be worth trying to take out that final cap across the PS, just to see if it makes any diff? It's a ceramic cap, COG or other?

John
I don't believe that is tha actual impedance at such low internal impedances, but the flatness of the impedance vs. frequency.
I have already suggested to Leo that he tries a 1,000 or 2,200uF low ESR electro in parallel to see if there is any change. (either way !)
Alex

[leo]

I can take the cap out , I'm not sure if there will be some ringing though even with the short leads. The cap is what was fitted as stock, its SMD across the Sabre pins, no idea if their COG or X7R .