diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Twisted Pear (http://www.diyaudio.com/forums/twisted-pear/)
-   -   Twisted Pear Audio - Buffalo32S (ES9018 DAC) (http://www.diyaudio.com/forums/twisted-pear/143315-twisted-pear-audio-buffalo32s-es9018-dac.html)

Russ White 1st March 2009 04:21 PM

Twisted Pear Audio - Buffalo32S (ES9018 DAC)
 
Hello Folks.

Brian and I have had many good conversations about knowledge and experience we gained from the first Buffalo DAC.

We came away knowing that the only way to really optimize the DAC was to compromise less. Not to worry as much about flexibility and worry more about absolute performance.

So when I sat down and reworked the circuit I looked back through my notes from Dustin at ESS as well as many of my most respected friends. The key thought that kept recurring was short signal paths and low noise.

So along those lines I proposed that I include a better more tightly integrated I/V stage with the Buffalo. Dustin's work was the most illuminating here. We found his observations about the output stage extremely useful. Most importantly he showed me that to get the best out of the DAC I needed to rethink my modular approach to the I/V stage. It was certainly working, but to get that final degree of sweetness it needs to be more tightly integrated.

So what I have done is married the I/V stage and filter to the analog section of the the DAC and both to the AVCC regulator. I don't want to give too much away here, but the output stage is very tightly coupled to AVCC on each side of the DAC. GND planes are separate for both AGNDs and GND. They are joined at a single point with a ferrite.

The output stage now symmetrically loads the DAC with an ultra low impedance virtual GND which reduces the modulation of the output voltage. The goal is low distortion and high dynamic range. While we had that before with the original Buffalo, it should be even better now.

So in short we traded "tweakability" in the Buffalo32S for a solid optimally routed design with no compromises to analog and digital signal routing which would be required to accommodate tweaking.

So the bottom line is the new Buffalo32 combines a re-factored Buffalo with better voltage regulators and a better clock with our newly redesigned output stage. All in one neat 3.125" x 4" unit.

Now most of you (about 90% plus according to our records) use the IVY with the Buffalo. This board is going to make your life significantly easier. This DAC will take up much less space and result in far better signal routing and wiring.

Now, before you other 10% start to groan. This is not the only new DAC coming. We will have a much more "tweakable" board coming. But you have to understand. Making a board "tweakable" means two things have to be accounted for. First, it will definitely not be suitable for beginners, and we will not cater to beginners with it. Second, it really cannot be routed as well as a finished solution because quite simply, you have to make design decisions final to optimally route a board. Building in flexibility means compromise. You will have much more to wire, and you will have much longer signal routes. That is the compromise. There is no way around it.

So we recognize we have two basic categories of users with lots of folks in between. Those who just want to listen to music through a well engineered DAC. For them the choice is the Buffalo32S. It is a DAC built from the ground up for the best practical performance based on our experience with the Buffalo. Then there are those who just have to experiment. For those we will have a solution too (yet to be named), but for now our focus is Buffalo32S. It is meant to do one thing well. Reproduce audio. :) The only components (beside case and connectors etc) required to finish a DAC with the Buffalo32S will be power supplies. That's it.

Expect more news soon.

P.S. Buffalo32S was chosen as a name because it is an all in one stereo DAC solution based on the Sabre32 platform.

Cheers!
Russ

TheShaman 1st March 2009 04:36 PM

Just make sure you order lots of boards, Russ.
Hate having to step on dead bodies to get mine.. :D

Keep up the good work!

rjbaldwin 1st March 2009 04:42 PM

Thanks very much for the 'heads-up' Russ, it seems to make the best sense for everyone and it pretty much fits in with my thinking... and I will be getting both boards ;-)

I look forward to hearing the finished article, I was kinda hoping it would have a Counterpoint output stage though, this seemed the best approach for real High Fidelity?

Russ

Russ White 1st March 2009 04:57 PM

Quote:

Originally posted by rjbaldwin
I was kinda hoping it would have a Counterpoint output stage though, this seemed the best approach for real High Fidelity?

Russ

Hi Russ,

While I quite like the counterpoint, I have to be honest that it simply is not going to be as faithful as IVY II. You just can't achieve the level of matching required to attain it.

Is Countrepoint very good, and lots of fun to build? Yes it is... :)

There really is no way I know of to get the same level of performance with a discrete cct as we can get with the IVY II.

We should have some news about Counterpoint shortly too.

Counterpoint is working well, but it really is not turning out suitable for single ended use because of the transient on turn off. This transient is common mode and as such creates no problem for balanced outputs. But if you try to just take one leg of the output you will see a nasty thump. You will want to run counterpoint either strictly balanced output or into a balanced to single ended converter.

I thought that the relay I added would help for SE use, but it does not clamp fast enough. Still, it does do the job of allowing the cct to settle on turn-on very well.

Cheers!
Russ

mikelm 1st March 2009 05:06 PM

Quote:

Originally posted by Russ White
There really is no way I know of to get the same level of performance with a discrete cct as we can get with the IVY II.

Hi Russ,

Is this an objective or subjective assessment . . . or both ?

cheers

mike

rjbaldwin 1st March 2009 05:50 PM

Hi Russ,
thanks for the 'honest' advice. I was sure any IVY 2 would measure better, but had the feeling that the Counterpoint would just sound better, SE thump or not?

As much as you can gather from the specifications and comments of others who I trust, I was expecting more detail and a bigger soundstage with more depth and a touch more reality. Just the icing on the cake really , compared with the best, and no criticism intended of the current Buffalo/IVY setup which I'm listening to now ;-)

Russ

Beefy 2nd March 2009 06:54 AM

I'm a bit disappointed that Buffalo32S is not a drop in replacement, but such is life.

For those of us with existing Buffalo boards, will the IVY II also come as a standalone product in the old form factor?

Russ White 2nd March 2009 10:58 AM

Quote:

Originally posted by Beefy
I'm a bit disappointed that Buffalo32S is not a drop in replacement, but such is life.

For those of us with existing Buffalo boards, will the IVY II also come as a standalone product in the old form factor?


Hi Beefy, yes IVY II will be available on its own as it is suitable for many output DACs, not just Buffalo.

Unfortunately with the new clock and other redesign considerations there is simply no way to make it all fit well in the old form factor. Believe me I tried. :)

Cheers!
Russ

Joshua_G 2nd March 2009 12:01 PM

Quote:

Originally posted by Russ White



Unfortunately with the new clock and other redesign considerations there is simply no way to make it all fit well in the old form factor. Believe me I tried. :)



I prefer better quality over keeping the previous form factor.

HaLo6 2nd March 2009 04:01 PM

You guys rock, keep up the great work!


All times are GMT. The time now is 06:41 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2