[serengetiplains]

Oh my gosh, the sound of this DAC is out of this world gorgeous!  I've only just completed most of the wiring and have some clean-up work to do (like fix the grounding scheme, of which there is currently none!), and it needs break-in and other changes, but wow, out of the box it is ~beautiful~.

The wooden cans you can see on top of the DAC are output transformers ... 1:10 ratio or some such.  They're doing fill-in duty until I get a new chip from Vincent (the DAC's designer) to route signals in ways I've intended for this particular unit.

Let me explain that.  This particular DAC has 3 channels: balanced-L, balanced-R and L+R subwoofer.  It is currently programmed to operate each such channel in L+R mode, hence the output transformers doing substitute duty.  Output transformers for the balanced version of this unit are FineMet (Feastrex) transformers glued to the chassis beneath the DAC board.  These are 1:1 jobs that should give me enough voltage swing when the DAC is operated in balanced mode.

So ... the DAC is wired with 5 arrays of Hynes supplies, one array for each of the discrete DAC functions, being one each for:

• the L channel
• the R channel
• the subwoofer channel
• the analogue chips
• the digital chips.

Each array is as follows:

transformer --> 12VDC series --> 9VDC series --> 5VDC shunt

The one exception is the array for the digital chips which adds a 1.2VDC reg for the main digital chip.

Each of the L and R channels operate in balanced mode (or will do so when I get the new programming chip), hence are better off, methinks, with the single regulator array dedicated to them.  Noise generated on these rails will sum in the output transformer.

I've also added passive filtering after each transformer to keep power supply noise from these arrays from interacting.

Like I said, the sound is off the charts.  I've never heard digital with such fine, delicate detail and resolution.  Thank you to Vincent and Paul for their awesome awesome products!

[serengetiplains]

This is the power supply chassis.

[serengetiplains]

The resolution of this DAC, being an R2R variety, is limited by the tolerance and absolute resistance of the resistors.  For this particular iteration of this DAC, I sourced and had Vincent install 0.001% tolerance Vishay nude Z-foil resistors, themselves spec'd at the very high values of 79K and 39K51 (normal is 20K and 10K01).  The always gracious and helpful people at Texas Components, where I purchase all my resistor products, were able to burn 0.001% tolerance resistors, down from their 0.005% stated lowest value. 

The DAC therefore has, I would guess, the highest output impedance of any DAC in the world!  lol  That impedance will be fine run into my tube headphone amplifier and is a wee bit high for my current test setup, which comprises a portable headphone amp.  Resolution is awesome, and this on 44.1K material.  The DAC is currently being fed by an Empirical Audio OR5 tricked out with Hynes supplies.

And one more point, the 9V and 5V regs use Vishay Z-foil SMD resistors purchased, again, from Texas Comp.

[tubesguy2]

Mods: Might I suggest that this thread be moved to the "Cheap and Cheerful Hifi" forum? 

Seriously beautiful stuff.

[cab]

Cheap? Really?

[serengetiplains]

Yeah, it's not very cheap.  Apart from that, it's a very carefully thought-out design.  Paul's supplies give a very low noise level, which when I jig the programming into balanced mode will be aided by the output transformers.  Awesome.

[serengetiplains]

Wow, this DAC with Hynes supplies is one serious piece of equipment.

[bmichels]

serengetiplains, I understood that you are using this DAC with headphone connected to the headphone OUT that is on the back of the DAC.

 If it is correct, then I will be very interested to know what is the quality level of the internal Headphone amp.  Indeed, I have some Fostex TH900, and I wonder if I need to buy a very high quality +$1000 headphone Amp (like Eddie Curent's Zana Deux or balancing ACT)  to use with this DAC or I the headphone OUT is good enough for a headphone guy ?

[goobicii]

this thread is EXTREMLY interesting!!!

I have so many questions,well first,whitch one of these Vishay Z Foil resistor Vincent use normaly and whitch one you put it? whats the difference? I searched mouser com but failed to indetify the "79K,, 39K51,,,,20K,,,10K01"  also only saw 0.0% and 0.005% there,no 0.001% as you mentioned

second thing is about PS,whitch PS Vincent normaly use,is this Hynes better? how much it cost?? Can I tell vincent to put Hynes PS in new TotalDac he will make for me??

last one... what TotalDac is it that you have in this thread,is it Dual or the cheaper d1-single??


oh and did you compare normal totaldac with your super duper uber resistors and Hynes PS?