A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

[dddac]

Originally Posted by Shinja

I suspect whether the delta sigma modulator runs properly.

why would you suspect this ?

also in the Killerdac forum, there are posts about questioning the working of the modulator. Of course I cannot look inside the chip to see what happens, but I can look outside.... ( and listen for that matter)

when I look (measure) I see signals coming out as I am expect them to be. sine wave is sine wave, square is square, triangle is triangle. fft analysis and linearity plots give no reason to suspect something is wrong.

on top the DAC just sounds great. also on 44.1 my listening experiences versus 192/24 should not be interpreted, that 44.1 SQ is not good. it is still top of the bill, it is just that 192 is so sweet

[clivem]

Originally Posted by jrling

I am!

I have tried:

1. A Cincon SMPS open frame chassis type fed by a 240v dual bobbin transformer (7.5v)

2. A 12,000 mAh mobile phone charger (LiPo battery)

I noticed both having appreciable SQ benefit over USB power with my WaveIO. The SMPS was more dynamic, and the battery power (offline of course) was more fluid but still very detailed. I am not using the 1794 DAC attached as I have yet to buy one, but am poised to do so.

OK, that's interesting. I know my hearing is not as good as it used to be. But I expect it is me rather than there is nothing to gained by using a very high quality supply for both the mainboard and the WaveIO.

I tried several PS solutions for the 12V supply to Doede's motherboard. Basic 7812 linear regulator, Salas shunt and the pre-built LT1764 modules I sourced from eBay. I couldn't hear any differences there. Same with the dedicated 5V supply to the WaveIO instead of being bus powered. I really wish I could say that the external power supply improved SQ for me.

Originally Posted by jrling

I can imagine many commenting adversely on both my choices of PSU from noise point of view.

Let 'em comment.... They don't have to do it that way if they don't want to. Too many people suffer with audiofool neurosis, where the audiophool "rules" demand eg. that any bit of kit using a switched mode power supply is immediately disqualified from being taken seriously before it has even been plugged-in!

[clivem]

Originally Posted by dddac

Hard to understand, why Clive did not hear any difference. I know what I heard and several others at the explicit listening sessions we did. conclusion: totally worth it. I also know indirectly from Lucian, that other WaveIO users had same experiences.

Yes, I don't doubt it. I think it might say more about me than it says about the benefit of using high-quality external power supplies!

[Panda2]

Thanks for the answers.

I believe that parallel boards sound amazing but what about SQ of just one board?
I need DACs for 8 channel DSP (car SQ) and it would be too co$ty for me to parallel them :-) so I would like to try with one board for 2 channels (4 boards for all channels).

Any idea how to use it with SPDIF source? I was looking for good spdif to i2s converter and found some but I doubt in their quality.
It would be a shame to use them with hiend equipment that I plan to use in my project.

Best regards

[clivem]

Originally Posted by jrling

I have Zu Druid Mk IV/Method Sub speakers which are 101 db efficient fed by a Bow Technologies ZZ-One 100w/channel integrated. So I have hair trigger issues! With 2v RMS output sources, I am on 7-8 o'clock max.

A bit of a mismatch there.... > 100db speakers and a 100W amp! What about a nice 2A3 SET amp or maybe one of Nelson Pass' low power designs if you have an allergy to tubes?

I like high-efficiency speakers. Have been using Lowther horn designs for years. (Which is another marmite moment for most. You either love or loathe, there is no in-between. ) Both of my pre's are passive. But I'm not a fan of a pot in a box, unless the pot is in the same box as the power amp circuitry. I like using autoformers for standalone passive pre's.

[jrling]

Don't tempt me!

Couldn't agree more ... but I love both. As they say "The first watt is the best."

Actually I have owned some lovely valve amps in my time and still have a totally original pair of Quad IIs in the cupboard. However, the Bow ZZ-One is a lovely Class A amp and it is staying!

[dddac]

Originally Posted by Panda2

Thanks for the answers.

I believe that parallel boards sound amazing but what about SQ of just one board?
I need DACs for 8 channel DSP (car SQ) and it would be too co$ty for me to parallel them :-) so I would like to try with one board for 2 channels (4 boards for all channels).

Any idea how to use it with SPDIF source? I was looking for good spdif to i2s converter and found some but I doubt in their quality.
It would be a shame to use them with hiend equipment that I plan to use in my project.

Best regards

The SQ of one board is already very good, the steps to more boards are clearly improving, but it does not mean one board does not Sound good

Have you read the sound check pages on my site?

Yes, spdif can be done easily

The Mainboard has an extra I2S Input, so this can be used for an external spdif Receiver. Like the one here: ---- click here ---- (it is the second kit)

[clivem]

Originally Posted by dddac

The Mainboard has an extra I2S Input, so this can be used for an external spdif Receiver. Like the one here: ---- click here ---- (it is the second kit)

This is not meant to be a criticism, just thinking out loud.....
The CS8414 (used in that design) will limit your input to 96kHz?

[dddac]

absolutely correct, but I assume spdif to be used with CD players or similar applications. if you have material at higher speed, this is not possible. Hence the USB solution...

[Panda2]

Hmm... I need 24/192 input to spdif receiver.

Probably I'll go with optical connection (galvanic separation) so I'll need TOSLINK 24/192 input and I2s output.