Twisted Pear Buffalo III DUAL MONO DAC Build

[SCompRacer]

Thanks Carl! Hey, you should know you could build two or more pres from the parts found in a Krell!

You and Ed either stay in the same room here or one of you stays with Jasper in his room. That is a locked down unit after lights out so you'd have to share his litter box too. As for the meth won't it kill the weed growing down there?

[SCompRacer]

Fred, was wondering if I could send you these Acko isolation/reclock boards with parts for the Amanero USB/I2S module. Show me your technique for soldering SMD parts. Video it and put it on you tube. Just do these two......then I'll know how in the future.... Larger board for the dual Potato chips.

[agfrost]

Where'd you get that giant dime from, Rich?

[FTGV]

.... soldering SMD parts.

That looks like some real fun right there Rich.

[dragon1952]

I was making op-amp upgrade boards for a while and having to solder the SMD's on boards smaller than the dime. Talk about "fun" :^ /

[bikerboy]

Rich,
I got a set also! Looks like oven baking is in the works. If I find the solder paste I'll let you know. I don't have much motivation right now due to the great sound I hear with the sdtrans384. I2s and wave files. Computer is used to convert flac to wave. Kind of like making cassette tapes. Ha ha. But sounds way better.

[SCompRacer]

The OT got cut so I'll be more rested and better able to deal with the tiny stuff. I just want simple, so the whole point of this excercise will be to see if isolation/reclocking improves the USB to I2S SQ at present. I have no noise/hiss/hum at full volume with no music playing now with the non-isolated Amanero. My expectation is the BIII clock will be better than the Amanero clocks. I could try just isolation too, but the smart folks say transformer or chip isolation alone adds jitter. Might be good to try it both ways.

The Potato chips are fast and said to handle well above 100Mhz clocks.

[strider]

Rich - How does the Otto work? If I wanted to be able to choose between an S/PDIF input and an I2S input from a USB module what else would I need?

[SCompRacer]

Ben, the OTTO II is a 2:1 Mux that can switch digital output between two four channel inputs. I use it in my DAC to switch between two I2S inputs. I’ve never used it to switch SPDIF but I think Brian at TP did and it worked. The TP diyaudio OTTO II thread.

http://www.diyaudio.com/forums/twist...ing-otto2.html

The only issue I can think of for you is input mapping. That is you have up to four channels of output (1A to 4A) plus GND to connect to your DAC board and how does SPDIF and I2S connect to your DAC board inputs. Your inputs on each channel (1B1 - 1B4 / 2B1-2B4) would have to be mapped to proper 1A-4A output.

You just add a jumper and pull up resistor to OTTO II and switch it by applying 4-5v. I tried it without the pull up resistor and switching was delayed. I use a mechanical switch in my Denon 3910 to switch OTTO II between I2S and DSD output. The only restrictions are the signals switched can’t be greater than the voltage used to switch it, which shouldn’t be an issue with I2S/DSD/SPDIF. Details are in the Integration Guide.

http://www.twistedpearaudio.com/docs...ide_V2.0.0.pdf

If using a micro controller (Arduino or equivalent) they can still pass a small voltage (like .009v) when switched low that kept my OTTO II switched on. I had to add a relay on the one in my DAC. No such issue with a mechanical switch.



The OTTO II in my DAC connects to a Twisted Pear Sidecar which is between my four channel SPDIF input board and DAC. The Sidecar just has one input and is switched by 5v so I get I2S/DSD input or up to four channels of SPDIF input for a total of six inputs. This was taken before the pull up resistor and relay were added.