Buffalo III - flexibility without compromise.

[milen007]

Page 39 in the integration guide:

http://www.twistedpearaudio.com/doc...-Buffalo_III_DAC_Integration_Guide_V1.2.3.pdf

thanks alot

how many idependent psu that you need for buffalo dac if you want to feed as many independent psu to each section of the dac?

i am new to this dac. so my quick look at the guide, i think can use 5 separate psu:
- 3 separate psu for 3 trident
- and 2 separate psu for analog section.

anything else?

is there any information on the current draw of each section? as i would like to supply with CLC raw psu only to each section. any possible problem by using unregulated raw power supply?

thanks
erwin

 

[merlin el mago]

Good catch Leif. Thanks Russ! I attached a corrected image noting B4 in this post. I don't have the power to delete or change the image in my prior post but would encourage those who do to change it or delete it. Thanks!

Do I ground B4 to the chassis, VG on the Sidecar or a ground on the external I/O connector header?

I suppose pin 3 GND of the external I/O connector, Russ or Brian could you confirm?

 

[Russ White]

I suppose pin 3 GND of the external I/O connector, Russ or Brian could you confirm?

Yes GND at EXT-IO which is the same as VD GND or any of the power GNDs.

 

[merlin el mago]

It's necessary to change R1 10K in Sidecar for R1 1 K in Sidecar?

 

[Russ White]

It's necessary to change R1 10K in Sidecar for R1 1 K in Sidecar?

It depends, if your driving it from ~5V the 10K will work fine. If your driving it from an LED spot (1.8V) you will definitely need something around 1K (even a bit less is ok)

 

[merlin el mago]

A pic explain more than 1000 words, waiting it's correct.

 

[Russ White]

It is correct except that B5 should be B4.

 

[merlin el mago]

Now it's OK?

 

[gwikse]

Would it not also make sense to turn off input remapping (B7) when sidecar is switched to i2s?

 

[Russ White]

Would it not also make sense to turn off input remapping (B7) when sidecar is switched to i2s?

No - for sidecar you would just leave it on.

You could switch it off for SPDIF, but it is not necessary.

 

[merlin el mago]

All selector switch LEDs don't lit, it's OK?

 

[Corpius]

The auto-detect feature is especially prone to false positive on I2S data. This means when using sidecar that if you have the DAC SPDIF multiplexor set to receive either channel 2 or 4 (which map to D2 and D4 on DIN) it will *very* likely unlock the DPLL from time to time as it mistakes the PCM data for a new SPDIF signal and attempts to lock onto it in vain, only to once again soon re-lock on the I2S/DSD. This is especially true at high sample rates (192Khz and above).

The Buffalo III firmware exposes the SPDIF auto-detect register to the user using I/O B4. When B4 is high (default state - switch 2:5 open) SPDIF auto-detect is enabled. When low (same switch "on"/closed) then auto detect is disabled (or "bypassed" if you will).

If you wish to use the 2-bit selector to switch between 4 SPDIF sources (using the SPDIF4 module) and the sidecar to switch between I2S/DSD and SPDIF you should always pull I/O pin B4 low on the Buffalo 3 when you have I2S/DSD selected. The best way to do this is with dual pole single throw switch. One pole should be connected to GND and "B4" on the Buf III I/O header - the other to 5V and "B" on the Sidecar. In this way when PCM/DSD is selected SPDIF auto-detection is disabled. You also get to use all 4 SPDIF selections.

Cheers!
Russ

If I got it right it should all be connected as shown in the image, Right?

But where to get the 5V from?

 

[LeonvB]

But where to get the 5V from?

One of your PSUs will do.

 

[BrianDonegan]

One of your PSUs will do.

You can actually get it from the VD terminal on the Sidecar, which is connected via the ribbon cable to the Buffalo's VD terminal.

 

[Corpius]

You can actually get it from the VD terminal on the Sidecar, which is connected via the ribbon cable to the Buffalo's VD terminal.

Right! Thanks!

 

[Takaji]

This is currently where I am with my BIII project: http://imgur.com/TxNPb The question I have is - is there an issue with the distance of the S/PDIF Switcher Board to the BIII? If needed, I could switch places with the IVY boards and S/PDIF Switcher board. I don't know if those I2S lines can be that long... will I have unlock issues?

The acrylic back panel is only temporary and is used as a placeholder for the final panel, which will be metal.

Any other electrical design-related questions are appreciated!

http://imgur.com/TxNPb

 

[gwikse]

Cool build. Perhaps you could shorten down the wires a bit by placing them like this.

 

[Takaji]

Cool build. Perhaps you could shorten down the wires a bit by placing them like this.

Great explanatory graphic! (What did you use to make it?) I can't really mount the BIII on the side, since it piggybacks on top of a USB-I2S converter, and then my custom 2-8 channel switcher is mounted on top of the BIII.

*If* the long lines are an anticipated problem, I could always swith places with the S/PDIF board and the IVY boards, and move the inputs to the same side as well. But then, the lines from the 2-8 switcher to the IVY boards will be longer, too.

 

[gwikse]

Ok. In that case I would place the dac board, the sp-dif input rca/optical etc. and those other boards in that stack to the same side of the ivy`s and align the sigma11 and sigma22 to keep the wires as short and to the point as possible (I use Google Sketchup 8 to make the 3d models).

 

[Krisfr]

Ok. In that case I would place the dac board, the sp-dif input rca/optical etc. and those other boards in that stack to the same side of the ivy`s and align the sigma11 and sigma22 to keep the wires as short and to the point as possible (I use Google Sketchup 8 to make the 3d models).

Did you use the regular or the PRO version of Sketchup?