Buffalo DAC (ESS Sabre 9008)

[muizel]

pic nr 2

[Studley]

Originally posted by muizel
Sound is fantastic thanks Russ and Brian !

Some context would be good - in comparison to what please?

[muizel]

pic nr 3

[muizel]

Originally posted by Studley


Some context would be good - in comparison to what please?

Hello Studley,

I spend a lot off time to listen between my Sphinx project nine
and Philips SACD1000 with APL modification, not alone but with friends and my wife , we all agreed that the sound was much more detailed and 3d without fatigue, you can listen the whole day long without feeling the need to lower volume or get irritated.

Anyway I am very happy.

[LIVE_EVIL]

Hi Russ and Brian ,
I ve sent you an email to orderstatus at twistedpear.

Have you received it?

Vitaly

[tubesguy]

Originally posted by tubesguy
Now I just need to find a few 10nf caps for the IVY mod, and then sit back and try to keep from screwing around with it too much more. - Pat

To follow up, the Capacitor Fairy left some of the appropriate caps in my mailbox yesterday (apparently accompanied by the Zero-Ohm Jumper Fairy) and I did the modification to the IVY last night, after allowing the caps to assume room temperature. (It's kind of cold in Wisconsin right now.)

A satisfying improvement, I thought, although I had been very impressed with the unmodded IVY. I'm not much up on the audiophile lingo, but I'd definitely say that a veil or two has been dropped, and the highs had gone from (comparatively) steely and bright to a wonderful caramel color (flavor?). Of course, the Buff in now ruthlessly revealing of any deficiencies in the source material.

Thanks again guys, for a great product and great service. - Pat

[glt]

OK, this is my (limited) understanding of the analog power path.

the regulator buffer looks like a voltage follower preceded by a CRC filter. So the CRC filters the high frequency noise and the voltage follower just passes the remaining noise to the DAC supply pins?

The input to this buffer is output of the analog LDO regulator. Most regulators have noise figures in the 10s-100s uV.

So, if the local LDO noise figure is inherent in the device, how can cleaning the upstream noise (e.g. TPA dual PS) reduce this noise?

In other words, if you chain several regulators, you can improve load and line regulation, but is the output noise dominated by the noise of the last regulator? Thus it seems to me that the noise of the local LDO filtered by the CRC is the inherent noise of the buffalo analog supply line. (Plus the noise of the opamp but this is probably in the nV range)

[Joshua_G]

What is the gain of the IVY Balanced Linestage?

[Russ White]

Originally posted by glt
OK, this is my (limited) understanding of the analog power path.

the regulator buffer looks like a voltage follower preceded by a CRC filter.

The main purpose is to provide a very low supply impedance the analog pins of the device.

Also, If you look at the spectrum of the noise which needs to be filtered it is all (or rather nearly all) high freq. (80 and 160mhz mostly) The scheme used actually provides a cleaner AVCC then I had actually hoped. If you want to extend the filter even lower you can parallel the cap with 100uf or so. But in practical tests it made little difference if any.

Cheers!
Russ

[Russ White]

Originally posted by Joshua_G
What is the gain of the IVY Balanced Linestage?

0db from the DAC results in an output of ~2 VRMS.