Twisted Pear Dual Mono DAC / ESS Sabre 9018

[Rockman Rock]

My DAC project. Pretty much complete. Working on an isolation/reclocking board for my USB to I2S module. This started as a single Twisted Pear Buffalo III build. This year I went dual mono. Dual mono is nothing new for DAC's/players. it allows for maximum dynamic range of the DAC chip and best stereo separation/details. I’ve had some nice CD/SACD players and DAC’s, including ones I modded. This is the closest to analog as I have ever got.

TP has optimized the ESS Sabre 9018 DAC chip with no less than four shunting regulators for the DAC board alone. They also open up all formats for input. DSD (SACD), SPDIF and I2S (CD). I2S is the serial communication found in stand alone CD players. Clock and data are separate in I2S where clock is embedded with data in SPDIF. All DAC chip settings including 32 bit volume control are available.

I added Arduino I2C control with LCD display and Apple remote control. Arduino is free license and a smart fellow started the code for the Buffalo DAC’s. I just needed to modify it with some help for my application. I have six inputs. USB to I2S, Denon 3910 I2S (CD) and DSD (SACD), three S/PDIF and one AES/EBU. A switch on back of the Denon determines what format is sent to the DAC input.

It is an Italian chassis (HiFi 2000 Pesante) with their modushop front panel machining and anodize after machine. They offered the best cooling (drilled base, fully vented cover) and anodize after machine. Machining included recess for LCD screen, hole for rotary encoder and lettering. I did the paint fill on the front panel.

I used shunting power supplies for the DAC boards and discrete balanced output board. One bipolar PS for the left channel and one for the right/single ended out section.









Currently I play flac from a big hard drive through a Squeezebox Touch. The Touch connects to the DAC via coax out SPDIF. I snagged I2S and DSD off the board from a Denon 3910 between the transport and DAC chip. This outputs ot my DAC so I can play hard media.  Some DAC chips share I2S and DSD circuits which minimizes wiring. DSD is clock,  R and L channel.





DSD (SACD) swapped R and L channels so I had to add a digital switch to reverse the DSD channels before output. A mechanical switch determines CD or SACD output.



I snagged I2S off my Touch board to output to my DAC. I2S is only meant for short in chassis runs. A LVDS (Low-voltage differential signaling) transmitter and receiver in DAC allow for up to 100 feet with no SQ penalty. I use a LVDS transmitter in my Denon to export I2S and DSD. It preserves the clock, where a long wire run could add lots of jitter.






More pics at my photobucket site.

http://s417.photobucket.com/user/scompracer/library/Buffalo%20III%20Dual%20Mono%20Build#/user/scompracer/library/Buffalo%20III%20Dual%20Mono%20Build?sort=6&page=1&_suid=136798554681206564200393599087

[Rockman Rock]

The Apple remote pictured sitting on the Arduino code printed single sided. This code is uploaded to the Arduino control via laptop/USB cable. I have an external USB input on the left side of chassis tp program without removing cover. The remote allows for input change, 32 bit digital volume and DAC chip settings. Settings like DPLL bandwidth, Quantizer, FIR roll off mode, IR Bandwidth. Without the remote, those would be fixed with dipswitch settings. The Arduino will recall settings made for each input. I'd agree with anyone that 16 bit digital volume sucks but not 32 bit.

I connect the modded Denon 3910 or Touch with I2S out with a short Cat5 cable.

[StephenWVU]

Well, I am impressed. looks a little out of my comfort zone to do a project like that but fun all the same. I hope it works great!

[Rockman Rock]

Thanks for the kind words Stephen. The Arduino two wire serial control requires programming to work and took me way beyond my comfort zone. I've got like six months invested in the dual mono build. If it wasn't for the help of the DIY community it would have been just manual control via knobs on the front panel. I also had to learn to do some modeling in Front Panel Express software to get the front panel machined to spec.  It sounds great and was well worth the effort.

[Falcon]

That is freaking awesome Rockman!   But with a dac like that, what is the rest of the system?

[SunnyDaze]

That is freaking awesome Rockman!   But with a dac like that, what is the rest of the system?

Come on Mike, it's GOTTA be Soundesign.

[Reverend]

Very impressive Rockman.  Thank you for sharing.

[Rockman Rock]

Thanks for the kind words.

My upstairs two channel setup.

With a south wall setup the speakers are boxed by corners so despite the treatments I do end up with bass loading issues.



 
My west wall setup has the right speaker open to the main level and is my best setup.



Speakers are Innersound Eros MK III’s; hybrid ESL’s. MK III’s had Ultrastat panels. A high value dielectric covers the stator grids, so they won’t arc. Powder coating on metal stators does not always cover 100% on sharp edges so they can arc. (I had some MK II Eros with metal stators that required epoxy repair). An improved coating is embedded in the panel diaphragm. It does not rub or wear off so no worries about insects, humidity or pet fur. narrow sweet spot but since I got older I don't like to move around much.

A 600 WPC @ 4 Ohms active crossover bass amp powers 10” high excursion SEAS woofers in a eight foot long folded transmission line bass modules. A Sanders 700 WPC amp powers the panels. The amps are A/B and started out as Coda designs with double the transistors and larger toroidals.

Pre amp is an old Class A Krell KSL with KSL phono board. Both recapped and tuned up. Had a ModWright SWLP 9.0SE before that. My DAC sounds best balanced out so I needed a balanced pre amp.

Primary digital source is a 1TB hard drive with flac connected to a Squeezebox Touch that feeds a DIY dual mono DAC. A secondary digital source is a modded Denon 3910 that exports CD or SACD to the DAC. I host music meets occasionally and some folks bring hard media.

Analog is a heavy plinth Lenco idler drive with larger aftermarket stainless bearing. Arm is an Advanced Analog MG-1 linear tracking air bearing. Crude compared to the Rockports but at a fraction of the price. I bought the MG-1 used which was even better. I got two arms with the MG-1 deal. One has a Dynavector Karat 17D3 and one has a Denon 103R with aluminum body. Air compressor is in basement. Air line ran through wall with push lock bulkhead fitting in a media outlet (Cat5, phone).



I have a nice Pioneer RT-71 that needs a little work. Bulbs and belts minimum.

[SunnyDaze]

That's a great setup Rockman! Everything looks amazing.

[schwarcw]

Lookin' good Rockman!

I have been to Rockman Rock's listening room and heard that system in all it's glory.  Everytime I see those speakers, I think of Sparky and his near death experience!

Something make's me want to wet my fingers and touch the panels LOL!

Great sounding system!  I'll be coming over sometime this Summer Rockman!

[StephenWVU]

That system is at the very least aesthetically beautiful.   If the sound surpasses the visual appeal, which I am sure it does, that is audio heaven.

[Rockman Rock]

Thank you all! Sound is a warm neutral with tight bass. Very dynamic. They sound great at lower listening levels but will play at hearing loss levels for those times you want to rock out.

Everytime I see those speakers, I think of Sparky and his near death experience!

I had a pair of early MK II Eros like that! I was adjusting one speakers position while it was playing and got bit. At night, around 85dB listening level, I'd see this glow on the wall behind the speaker where it was arcing. Like in wood shop, you’d recognize that smell of burning your name in a piece of wood with a hot iron. The rear stator was arcing to the screw that held the panel to the wood frame.

Roger Sanders the designer told me how to fix them. Pull the panels, and put a thin layer of epoxy on the bare spots where the powder coat didn't stick to the stators. Then add a layer of Kapton tape. Later production MK II Eros had a layer of Kapton tape added on the edges of the front and rear stators before they were assembled. I also used some thin nylon washers so the screw wouldn't chip off the powder coat on the front stator when tightened. After that fix the speakers could play at 115dB on the rat shack meter without any arcing.

I took a pair of my friends Eros MK II's that were for sale to a big audio fest we had. We did not know that there was a bare spot on the inside of the front stator. A fellow wanted to connect his bridged amp to the panels and try it. That amp had protection circuitry and when cranked up did not like the capacitive load the ESL panel presents. That threw the amp into protection mode.

When that happens, depending on design, the "back on" voltage of the amp can be much, much higher than the rated output of the amplifier. I swear and have witnesses that a three foot flame shot out from the front of that speaker. It blew the breakers for the room along with a small hole in the ESL diaphragm. Fortunately nothing was destroyed, the amp and speakers lived. To fix the speaker, I had to bend and flatten a paper clip to carefully apply epoxy to the backside of stator without gluing it to the diaphragm. Fun stuff!

[Rockman Rock]

Forgot to add for the folks that might not know, the ESL panel stators are connected to the amp through a high-voltage step-up transformer. This magnifies the amps voltage output to the several thousand volts needed to drive the diaphragm.

[Kingman]

I WANNA ROCK!!!!! 

[Rockman Rock]

I WANNA ROCK!!!!! 

How about some House? This thing can track!

http://youtu.be/YYD9CIWJELc