Buffalo DAC (ESS Sabre 9008)

[Russ White]

Originally posted by fmak



Russ

You are prolific. Is this going to be available?

One question - is the previous vref based on the pnp transistor enough to drive the Buffalo LM4562? Or are you just developing a new feedback regulator?

My experience with the ALW regulator for general use is that a tracking preregulators improves performance significantly. The Teddy series pass prereg actually doesn't do anything extra.

Fred

Hi Fred, Thanks.

This regulator is designed to be used after a LCDPS.

The VREF alone is not meant to drive the LM4562 at all. It is there to provide the low noise 3.3V reference that the opamp tracks. The opamp *is* the VREG. The VREF's output impedance on its own is not stellar. It has to used with a very high input impedance, like the opamp.

With the exceptional PSRR of the LM4562 the LCDPS should work out very well. But you can use any regulator you like as long as you get a good low impedance 6 - 8V or so.

Try the VREF on the buffalo and see what you think. I am really liking it.

Cheers!
Russ

[Russ White]

Originally posted by masi
Hi

No big news, just wanted to say that my baby is up and running (including the new VREF). Everything worked as it should. Soldering and assembling was straight forward.
And what about the sound? All I can say: I'm very happy. To me it just sounds right - and that's fantastic.

Next thing will be a nice case - but first I'll have to sit down, take a deep breath and have some listenings.

Brian and Russ, thanks a lot for making this possible.

Cheers!
Mario

Wow! Very nice work!

I am glad you are enjoying it.

Cheers!
Russ

[glt]

Originally posted by Russ White
Here is a low noise regulator based on the VREF idea above.

The output (pass) device can either be To-220 or TO-92 depending on what you need.

I added the capability to take feedback(Sense) from the load instead of the right at the output. You just extend RF to the further pad and wire the sense wire to the pad marked "Sense"

Russ, If this becomes a product (please, please) you can add a pad to the Vref so the same board so it can be used for a Vref or Vreg. Thanks!

[rolls]

Hello
I hope there is anybody around who can help.
Yesterday I was happy, because the AV Ref mod works very well.
Then I wanted to add the MUX, but it does not work at all.
I have checked everything:
layout in the net and on the board of the buffalo are different, I don't know which is correct, I have tried both, without success.
When I follow the I2S markings on the board, buffalo locks, but the LED on the MUX is dark, even If I connected the missing ground link (I have an early board).
I have connected input one, for this select 1 and 2 are tied to gnd.
switch 1 on buffalo is neg
I have left the switches on the mux untouched.
All the voltages are O.K.
I soldered the relays that their point is on the same corner as the small white dot on the board.
When I switch to SPDIF, buffalo works, but with added clicks sometimes.
Thank you!

André

[Russ White]

Hi Andre

If you put the I2S output of the MUX board against the I2S input of the buffalo board, the terminals will line up.

Here is a pic I hope will help.

I have GND connected elsewhere, thats why you don't see it.

Data,BCK,LRCK

Add GND if your MUX and Buffalo don't share a common supply.

[Russ White]

Also, you cannot leave the switches open. Try setting them like this.

[rolls]

Hello Russ
Buffalo and Mux are stacked,
but DOUT to D2
LRCK to D1
BKC to DCK is correct I think.
I just hear loud hiss with faint music.
Ground is everywhere. Relays are O.K?
thank you!
André

[Russ White]

If you have a very very early Buffalo (very first run) remember that D2 and DCK are swapped.

Also, isolate the MUX itself and make sure its locking. Is the LED installed backward?

[rolls]

My buffalo is from the second round, the one with the hosting company problems you had.
I have removed the mux now, unsoldered and checked the LED, flat side is connected separately to ground. selectors 1 and 2 still to ground, no lock!
Slowly I start to think about to replace it with another mux.
Thank you for your help
Andre

[Russ White]

Yes, it sound like the MUX might be suspect.

If it won't lock on its own, then there is no point to proceed with it.

I guess maybe it could be a solder bridge or a dry joint.

Very sorry your having trouble with it.