Twisted Pear Buffalo III DUAL MONO DAC Build

agfrost

That's hot.

FTGV

So ya done yet?

They did a real nice job of anodizing and machining that front panel.

SCompRacer

Are we there yet? NO!:cheesygrin: I wish..... I was gonna pack it up and send it to you for final assembly.

Thanks for the kind words. Yes they did a great job. Even the spellin' is correct. I'll start drilling and tapping holes in the back of the front panel this weekend to mount the Arduino board/shield and IR receiver. Must remember to use depth stop on drill press......

I ordered a chunk of aluminum angle to mount the toroidal farm on. One problem, on back panel (painted steel) they punched out for an IEC socket and it is right in line where my tranny mount will sit (like 15'' / 381mm long...lol). Might have to patch and relocate the IEC line filter/fuse/switch assembly I am using. It is near 3" long.

FTGV

SCompRacer wrote: »

... I was gonna pack it up and send it to you for final assembly.

No problem and I'll even give it the requisite year long burn to save you the trouble.

schwarcw

Damn that looks good! You have a really nice Pear!:twisted:

SCompRacer

Thanks Carl!

I am making some progress.....I've moved the two small power supplies since this pic, but the config is similar. I hope to have Dana do the front panel color fill this weekend.:cheesygrin:

schwarcw

Keiko wrote: »

Have you thought about going vegan, Carl?

Attachment not found.

LOL!

Too funny! Merry Christmas to you and Janey!

Regards,

schwarcw

SCompRacer wrote: »

Thanks Carl!

I am making some progress.....I've moved the two small power supplies since this pic, but the config is similar. I hope to have Dana do the front panel color fill this weekend.:cheesygrin:

WOW!

That build looks terrific! I am looking forward to seeing and hearing the finished product!

SCompRacer

I am happy to say I am mostly finished with my Twisted Pear Buffalo III dual mono build! I had to take an existing light picture of the front panel in an attempt to show what it looks like in real life. The flash tends to really lighten the color fill in the front panel engraving.



I am waiting for an Amanero USB/I2S module, and Digi Key mis-packaged the incorrect value resistors for the AES/EBU input. The USB input is just a hole stuffer for now. I plan to redo the rear panel labeling when I install the USB module. I am thinking up high near the Teleporter to keep the I2S wires short. An OTTO II for switching between the two could be added. I tried to think modular in that the rear panel, front panel and toroidal farm can be easily removed if the need arises.

I drilled and tapped holes in the front panel to mount the Arduino board (pictured with Corpius's shield) and IR receiver board. I also drilled a cavity for the IR receiver to get it closer to the face of front panel and give me greater off axis remote control. Somehow I removed that cavity during the numerous changes made to the design in front panel express. It would have been nice to have more or all of that work done by the CNC machine. I was unsure of where the Arduino would be mounted until I had a roughed in assembly.

I am glad I went with the Hi Fi 2000 drilled base option. It made assembly easy and really stiffened up the chassis. After getting the components positioned and wired, I added the "walls" of the enclosure. My heavy toroidal farm wouldn't do well installed on just the lower panel. A big plus, at least two holes of every board lined up with pre-drilled holes in the base. Andrea at Modushop was very helpful and nice to deal with while I was finalizing the front panel machining.

Due to my inside out assembly procedure and the toroidal farm blocking access, I stud mounted the front panel. There is just enough room to swing a small box-open end wrench to tighten the nuts, although getting a washer and nut on is tricky. A short USB cable is connected to a Neutrik D panel USB connector at right front side of enclosure so the Arduino can be programmed without removing the cover.

You might notice two holes drilled in the rotary encoder knob cavity. This was a last minute addition for a future project. Even though my LCD will display 'lock,' I'll add LED's for lock and mute behind the knob like I saw some folks do. I'll get a different color for mute and use my original green one for the lock.

The Testors paint fill of the front panel went well. They didn't have the exact shade of green to match the Twisted Pear logo, se we mixed some white in to lighten it. I went with Testors as ModWright used it and it still looks good after a few years. It is very hard to stay "in the lines" of the engraving with the color fill even with a tiny artists brush. I found a new bondo spreader used as a squeegee moved most of the excess paint to an area where it could be wiped off the panel without removing paint from the engraved areas. After allowing the color to set a few minutes, I used cotton swaps moistened with thinner to get the smeared paint off. It leaves a film that can be easily removed once the paint dries. I followed up with an old dish towel wrapped tightly around the spreader moistened with thinner. It was a smooth tightly woven towel (not fuzzy). The plastic spreader did no harm to the front panel.

The toroidal farm mount is thick 1/4" (6.35mm) aluminum. It started out as a 4" x 4" angle I cut down to 4" x 1.75." The cut edge and radisued corners were smoothed with a DA (double action) sander. I drilled and tapped threads in the mount to make it easy to install to the base. I couldn't locate any rubber grommets for that thickness material to insulate the wire pass through holes. A trip to the local Ace Hardware for some metric screws got me looking thought their hardware offerings and I found some snap in plastic bushings. They had an assortment of small to larger sizes. I used 3/8" (9.5mm) for the secondary wiring and 1/2" (12.7mm) for the mains power. They were 3/8" (9.5mm) long so they extend through the thick transformer bracket.

Some folks have asked me why so many toroidals. Well I had the Twisted Pear LCDPS and LCDPS linear power supplies from early testing with the single BIII build. (Sounded better to me with the shunting power supplies). I used the + side of the LCBPS to power the Arduino/LCD. One side of the LCDPS powers the Sidecar/4 channel input board and the other side powers Teleporter and future USB module. I could lose one 9v tranny and split the secondaries on the remaining one to power the two Placid HD's, but then I lose galvanic isolaton beyween those two supplies. It was so quiet even with the rats nest wiring in the friendly case that I did not want to risk possibly adding any. The two BP (bi-polar) power supplies require both secondaries for the - and + rails.

schwarcw

Absolutely stunning DIY effort! WOW! The aesthetics are first class.

Did you sniff any of that paint thinner? LOL! Give the green color a little sparkle LOL!

Great job Rich!

SCompRacer

Thanks Carl and Mike!

LOL I had a straw and deep inhaled Carl! Enamel gives a better buzz than latex water based! (Actually the Testors thinner stinks awful, mineral spirits are more better). Ed gets the assist for pushing me into this dual build.

Mike, the shipping would break us, its too heavy! (And no tubes).:eek::cheesygrin:

Some of my buds are beating me up about the blue LCD so a green one will be added sooner than later.

chumlie

WOW just WOW !!! Beautiful job.

SCompRacer

Thanks Chumlie!

I have a green with negative backlight on order. Like $12 to get rid of the clash.:cheesygrin: It will be a drop in swap.

chumlie

Much better with the green.

EndersShadow

Lasareath wrote: »

WOW everything looks Great!

Can you make the display out of Nixie Tubes?

Attachment not found.
http://www.ebay.com/itm/10-DIGITS-IN-12-NIXIE-TUBE-CLOCK-WEB-COUNTER-2-ALARMS-/250939455334?pt=UK_Sound_Vision_Other&hash=item3a6d283766

I soo need one of these for work.... Just because I need tubes somewhere lol....

strider

Top notch, Rich!

Really digging the transformer set up/wiring. Very nicely executed; that would have been a perfect scenario for a rat's nest. Any reason to be concerned about noise or hum from the torroids with them so close together?

Amherst

Incredible....Absolutely Incredible work and execution.

Congratulations!

Now it's complete......Enjoy the Music!

SCompRacer

Keiko wrote: »

No tubes and no catalog? Keep it!

Mike, you know what they say, if it has tubes or **** sooner or later.....:cheesygrin:

Lasareath wrote: »

Can you make the display out of Nixie Tubes?

Thanks Sal. You probably could make it work, but a 4x20 character display with those is way beyond my programming skillz.

SCompRacer

strider wrote: »

Really digging the transformer set up/wiring.....

Thanks Ben. In regards to the toroidals, this is the layout I had in the friendly case and it worked fine; no hiss, buzz or hum, with 1/8" between them. IIRC I had asked Fred and he said I should be OK too. The wiring in that thin case was far more of a rats nest than this one with mains mixed/or near secondary wiring. I strived to keep AC wiring 1/2" from chassis where possible. It passes my full volume with no music playing test.

I've seen some Buffalo builds where they actually stacked toroidals. They claim Avel gave their blessing to stacking saying it was OK.

I used Teflon insulated wire to extend the secondary wiring and maintained color code. (Teflon doesn't shrink back when heated). I used red zip ties to ID the 30VA tranny wiring and blue ties for the 15VA's. All AC wiring is twisted. Extension splices soldered and shrink tubed, all connection ends tinned. Mains power enters through a Shurter filter/fused/switch IEC module. I also used Teflon insulated wire to connect power supplies to boards and tinned the ends.

Amherst wrote: »

Now it's complete......Enjoy the Music!

Thanks! You know I will be! I can actually leave the DAC upstairs now as it has a cover. (We got a nosy cat).

schwarcw

Rich, break out the tunes! Spanky and Our Gang, The Association, Blue Cheer, Rick James, some Cher, Barry Manilow, Vanilla Fudge, Moby Grape, Manilli Vanelii the killer sound from these artists will be worth all your hard work! Spank on! :twisted:

SCompRacer

Hey Carl! We busted some moves to the KLF too! What Time Is Love? This sounds great at hearing loss levels!:cheesygrin:

Right now......right now.......right now its time to...... kick out the jams m#%*f$##$s! :cheesygrin:

http://youtu.be/28w2LVzxVkU

schwarcw

Lasareath wrote: »

The Milk's gone bad!

It's the Kool Aid we drank! LOL!

schwarcw

SCompRacer wrote: »

Right now......right now.......right now its time to...... kick out the jams m#%*f$##$s! :cheesygrin:

http://youtu.be/28w2LVzxVkU

Rock on wit yo bad self!

FTGV

wowThat's what you call raising the bar!Awesome work Rich.

SCompRacer

Thanks for the kind words Fred!

Got the green on black LCD today. A drop in swap. Looks much better.

chumlie

Damn thats pretty. Much better than the blue. Beautiful job. Whats next ?

FTGV

Agreed the green display adds the finishing touch.

schwarcw

WOW! The green display is just stunning on the faceplate! Great job Rich.

SCompRacer

Thanks again for the kind words.

chumlie wrote: »

.....Whats next ?

Well, no USB to I2S module arrived yet. I do get slight gains using I2S over SPDIF coax in (I2S separates clock from data where clock is embedded in SPDIF signal). Also remember that the ESS Sabre DAC chip handles SPDIF differently than other DAC chips (does not rely on embedded clock signal). To expand on I2S, folks at diyaudio have been re-clocking the I2S signal before handing it to the DAC chip(s) for even less jitter and better SQ. I'm gonna wring out all the possibilities and stick with the best one.

Next - next up might be a DIY phono stage. I went with a balanced Class A Krell pre amp with MM/MC phono board as the DAC was designed to run balanced (although single ended ain't bad at all). This means dropping the ModWright SWLP with its incredible phono stage from my line up. The Krell MM/MC stage has some MC noise issues in left channel I am running down, but it also has less MC gain compared to the ModWright resulting in high clock position of volume control for 80-85dB listening levels. That high volume setting seems to leave little headroom, thus dynamics suffer. I'll try an MC head amp to boost phono input into the Krell and hear what happens.

A big thanks to Fred for directing me to the Twisted Pear Buffalo III DAC and all the tips he provided along the way. I ended up here after doing some extensive mods to a Music Hall 25.3 DAC. Even though I read how much power makes a difference in a DAC circuit, once I experienced it building from the ground up was more attractive than putting more money into an existing design. I am also not limited with current input format or sample rates. Hard media via modded CD/SACD player, SPDIF, I2S and native SACD (USB soon), up to 32Bit 384Khz and 6.144Mhz files.

SCompRacer

Received my Amanero USB to I2S module today! This started as a temp install in my DAC although it is quiet with no music playing with volume ramped up to full and sounds great with music playing. Temp in that I am not ready to remove and cut a square hole in back panel, so I may leave it as is. I only have a hi-res (24/96) vinyl rip of Bolero on the laptop and vocals of left, right, both, so I need to fix that and do some listening. I am using foobar and ASIO drivers for now.

There are better USB to I2S modules that are isolated, but not many play I2S AND native DSD over USB (not dithered down to PCM) and can cost up to $450. This one cost me $50 on a group buy (60 or more folks required to go in). It isn't isolated but so far quiet with the laptop I am using. I can add isolation using an NVE IL715 but it could add up to 100 picosec of jitter (which is low, as it is one of the better isolators available). A recent firmware addition corrects the DSD R and L channel swap so I won't have to fuss with that in software or digital switching. If I stay with USB to I2S, I'll have to add an OTTO 2 digital switch so I can switch between the Denon or USB input. I'll use a switch to select between them like I do to switch between I2S/DSD out on the Denon, no more coding!

I had installed a Neutrik type A/B USB panel mount connector when I built the DAC. I don't have any USB B connectors here (on the way though) so I cut and spliced a short USB cable but did not connect the USB power wire. This way I can power the Amanero board by one half of a Twisted Pear LCDPS (clean linear power supply) adjusted to 3.3v, not computer power. If I mount the Amanero on rear panel I'll remove the on board voltage regulator......that way a powered USB cable can be connected and not power the module. Lighted magnifier work for me as the regulator is very tiny with SMD's by it.

I used three lengths of small coax to connect the Amanero board to Sidecar. The three coax grounds are all connected to the Sidecar ground pin. That helps shield the I2S signals. I got this coax from some old S Video cables lying around.