Experience with this DIY DAC ?

Bit perfection? another perfectionist like myself....

is this the process of getting bits to flow perfectly from harddrive, through media player, through operating system and out of soundcard?

if so, i used j river media player a few years back to send flacs through an asio 2 driver enabled soundcard out of spdif....

so now i have to do a refresher course as have not been using digital tunes for a few years, but would love to hear your version of bt perfection to kll some tme

keep us updated about tamuras

cheers stuart
 
surfstu said:
Bit perfection? another perfectionist like myself....

is this the process of getting bits to flow perfectly from harddrive, through media player, through operating system and out of soundcard?

if so, i used j river media player a few years back to send flacs through an asio 2 driver enabled soundcard out of spdif....

so now i have to do a refresher course as have not been using digital tunes for a few years, but would love to hear your version of bt perfection to kll some tme

keep us updated about tamuras

cheers stuart

As far as I get it, bit perfection is getting bits from source file (in my case FLAC) to SPDIF (coax or optical) untinkered - i.e. no resampling, no volume adjustment, no inside-a-toilet effects etc etc.

This page is a good description. The guy has written drivers for soundcards based on a certain chipset (here) to provide bit perfect output.

Tonight I had a good shopping trawl and ended up with one of these should you need one. Nice and cheap! Next best price was this.


Cheers

Oli
 
cheers Oli,

i use a presonus firebox, but only because i dabble in recording music too, the card looks good, good price too... personally i have always used spdif, not sure if ths card has one? Seems like you've found bitprice perfection!

Still looking forward to legarems verdict on the tamura transformers....

will the resistor that is put across the secondaries depend upon the input resistance of my preamp?

stuart
 
Just to clarify, S/PDIF is a data protocol/spec. The S/PDIF signal can travel over either a coax or optical cable. It seems to be well debated as to which is better - which says to me they're about equal! I'll stick with optical to isolate DAC from my noisy PC. NB I saw this other cheap bitperfectable sound card which has coax output.

This issue very relevant to getting best out of our lovely DACs but, yes, it is all rather off-thread, so I'll shut up now!
 
Back to the chinese High End "DIY" DAC:

I sent to Marc a pair of Digitecs, as he has the most different tranny types to compare with.

Let's wait for his experience!

In the meantime, I finished to build in my small Super Pro 707 DAC in an enclosure, including PSU and output trannies:

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An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


The first finished project for some (long) time :D

But: now I recognize, the simple circuit of this small DAC is really different than the upsampling 192kHz DAC, the object of this thread.

The upsampling DAC is much better than the small 707.

The big one is superb!

So, I plan to build it also in a separate enclosure and I will order a second one, to build it in to the Studer 52 amplifier, I mentioned before in this thread.

Franz
 
Franz Gysi said:
But: now I recognize, the simple circuit of this small DAC is really different than the upsampling 192kHz DAC, the object of this thread.

The upsampling DAC is much better than the small 707.

Franz

Thanks Franz, interesting. I was considering this 707, as it has the same receiver & DAC chips as the big one but also has an input for 12V external built in - ideal for my battery power plans!

I have not seen the circuit, but I do notice there are not so many big caps - is the main difference the power supplies? If so, then maybe battery power could really improve the 707. Or is the receiver/DAC chip implentation also very different? We do not need analogue stage of course.

Cheers

Oli
 
Tamuras are playing

I received the tamuras today

They are neat little encapsulated transformers with wires instead of soldering lugs

I connected them to a CS4398 dac without upsampling ( the one with digital input transformer)

First before connecting them to the dac, I made the usual tests to determine the optimal load with this transformer.

I injected a 20khz square wave to see what is the beat load to obtain the best square wave. With a load of 47 k, there's a lot of rigning. When using a pot at the secondary for load, the square wave is really PERFECT with loads under 1.2K. This is a 600 to 600 ohm transformer.

Now about the sound

Unagressive sound with plenty of details. The bass is ok, detail is there and highs seems silky smooth with detail.

I think that this is a winner. I will listen it more and will give you my impressions in comparaison with the Lundahls later

The only drawback is that sound level isn't too high as they are connected now with secondary loaded with a 680 ohm resistor.
 
hi Legarem... Mark?

thanks for the tamura update, i look forward to recieving mine...
and the 4398 dac to go with them!!

i was hoping you could share more on your findings as i will be using the same dac as you. I'm not too clued up in this area and hoped you may enlighten me as to the colour coding of the tamuras wires, and have you just shorted the secondary with a 680 ohm resistor before the rca output? is this signal to ground on both channels? or signal to signal across the channels?

thanks stuart
 
I will scan a drawing tonight to show you how I connected the transformers with the color codes.

I listened the tamuras again last night before going to sleep and I found the soundstage amazing. The sound remains me the sound of a small band in a bar which means that it is VERY natural and unagressive. Those who loves turntable will probably fall in love with the Tams. They are not rolled off at all in the highs,

The sound coming froms these transformers can be listened many hours without listening fatigue. I was surprized that I cranked up the listening volume higher than normal without being agressed.

Franz. There is a 1K resistor between the dac Out + and the transformer and another one between the dac Out - and the other leg of the transformer. With this topology, the load to the dac is near 2.68 K.

Tonight, I will do a comparaison between the Lundahl and the Tams

I presently use two dacs. The one with upsampling board which have Lundahls. The other dac don't have any upsampling but have an input digital transformer.

I will settle the upsampling dac in non upsampling mode to try to get the same situation on both dacs. The older dac with tams will have the advantage to have an input digital transformer. I will perhaps bypass it.
 
Here is the schem showing how to connect these transformers.
 

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Havoc08 said:
@ Franz
Is that a case from hifi2000 or what the name is of that italien case manufacturer that is sold from autoconstriure etc.?

Does it have a fake bottom for mounting the pcb etc. or does the screws come out on the bottom side? (I.e. not pretty)


You can get this case from http://www.autocostruire.com/ or http://www.modu.it/

The top and bottom are removable but you will need to drill holes through the base to mount your components. Is this really a problem?