NOT QUITE NEVER AGAIN, THE GROUP BUY DAC BUILD

[randytsuch]

ive ordered some of these for testing

for that purpose i was gonna use ndks maybe even steal them off the diyinhk usb board

Nige
Where did you get this adapter from?
Searched, and could not find, and I could use a little adapter like this.

Thanks
Randy

[nige2000]

i found a few on ebay, and the last ones i got from wendy in china
https://www.ebay.com/itm/10-PCS-Active- ... 2144352400

[randytsuch]

i found a few on ebay, and the last ones i got from wendy in china
https://www.ebay.com/itm/10-PCS-Active- ... 2144352400

Great, thanks for the link

[Ivor]

I had the honour and privilege to hear this DAC yesterday in my own system. Fran and Derek came to my cave yesterday for a listen to music, to talk incessantly, drink coffee and generally have a bit of craic. Fran brought up the NQNA DAC (see thread title for acronym explanation). After we'd warmed up the system with some old fashioned analogue recordings we plugged the new DAC in.
Now I'm not going to get into any digital Vs analogue debate because it serves no purpose. Horses for courses, individual needs/tastes etc and everyone has a subjective notion of "better". To be upfront I love analogue, that's my preference. That's all it is.
Now to the serious stuff...

From the first notes (was it Gillian Welch first up?) there was some serious weight to the sound, musicians had depth and width and even height. A true 3D render. Fran can elaborate on the difference when switching from mains to capacitor power (he can also correct me of I'm wrong there!) but switching from mains feed brought even more "heft", detail and sparkle. The music played was broadly familiar stuff and it was a joy to hear it reproduced so well. Now, what was really interesting is that the files were played off an SD card and the resolution is limited to that of a standard CD. This was not a sound I ever heard from a "red book" CD! I really look forward to hearing high res files via USB through this wee beastie. I can't imagine what that'll be like!

[cybot]

Never mind the DAC 'Eugene', what did the lads think of your Harbies?

[Derek]

The lads loved the "Harbies", always have. Well matched in Ivor's setup, Airtight driven on dedicated, made for purpose stands, just brilliant.
The sound is a reminder of why I got into Hi-Fi, beautiful highs, glorious mid-range and a really well balanced bass, nothing overblown or out of sorts. We pushed through all kinds of music and nothing phased them; rock, country, soul, jazz, classical; they're remarkable speakers.

[Fran]

^^^^what he said

[cybot]

Wow! Can't say better than that.....Long may they shine!

[Ivor]

you're all very kind. I have to say that yeah, they do everything asked of them and do so effortlessly. I'm a lucky custodian.

[gstew]

A very impressive project... following closely!

A question to those who have heard this beast... I've also been using Ultracaps in some recent power supply setups. I have 3 of Ian Canada's UCPi boards and originally built them up using the Nesscap 325F/2.7V parts (which I think are the same units you used in this build) and then later with Maxwell 350F/2.7V parts.

I have used these supplies mostly with a somewhat tweaked out Allo.com Katana ES9038Q2M-based RPi-mounted DAC with Sparkos discrete opamp output stages. The UCPi provide power for the 5V to the DAC board and the 5V to the Microprocessor board (which others have found to impact the sound, even though it is not in the 'audio' stream). I generally run these both float-charged by an Uptone Audio LPS-1.2 set to 7V for each which charges through an on-board 5V LT3042 regulator (and with that limited to 200-250mA, it takes about 30-45 minutes to get up to 5V from empty!). With this setup, I hear VERY little difference while running in float-charge mode versus not-being charged (which will run some time due to the high capacity).

The RPi is powered by a good AC 5V supply, the output stages by a good set of +-15V AC supplies.

In many ways, these are the best supplies I've used in this setup. They are very articulate and detailed, with the lowest overhang and energy dispersion I've heard, resulting in great dynamics, intelligibility, and drama factor. BUT the frequency balance is a little different from my other good supplies (a modified Allo.com Shanti which has 2 5V outputs and a string of 1.5F/2.7V Ultracaps as the final element in each outout), 2 12V AC-connected supplies regulated to 5V using 2 MPAudio 6||LT3045 boards, and the same 2 MPAudio boards fed from the Uptone Audio LPS-1.2s' as above.

The other 3 supplies have a somewhat phatter bottom, phattest on the 2 AC-connected supplies and slightly less on the other LPS-1.2-connected supply. The LPS-1.2 float-charged Ultracap supplies seem lighter on the bottom, though when there is content in the lower mids and bottom registers they sound very strong and detailed. I suspect a lot of the phatter bottom is due to the electrolytic caps in the other three supplies and that I've 'voiced' my setups for them over the years. It is not a huge or bad difference, but I do notice it.

Also, I found the Nescap parts to impart a bit of a raised shelf in the upper-mids through lower-treble. That's why I went away from them and was happy to hear that the Maxwell parts didn't exhibit this.

I also have one of Ian's LiFePO4 supplies powering his group-buy RPi DAC cards. It has 4 non-float-charged LiFEPO4 rails... 2 3.3V (for the DAC card and the FiFoPi isolator/reclocker combo) and 2 13.2V (which I use as +-13.2V for the output stages, in this case either Sparkos or Burson discrete opamp based). I need to try the UCPi for the 2 3.3V supplies here now that I have the Maxwell's in the UCPi... when I tried one of his DAC cards with the Nescap-fitted UCPi, I heard that raised shelf also on that setup. BUT I mention this setup here because the frequency balance I'm hearing from that mostly LiFePO4-powered RPi->FiFoPi->DAC card->output stage has a frequency balance closer to that of my AC supplies, though it seems to lack a bit of articulation and speed compared to the Ultracap supplies (not much though!).

Are you experiencing any difference in the overall frequency balance of this DAC setup versus others with non-Ultracap supplies?

I've tried a couple of things to adjust the balance... first was placing an Aerospace Evans Hybrid cap (large-scale Tantalum electrolytic caps as I understand) at the output of the UCPi... phatter bottom end, but it lagged the mids-upper to a noticable amount. Second was to charge the Ultracaps to the target voltage using the 200-250mA-limited regulator on the UCPi, then jumper that and use the MPAudio 5V 6||LT3045 powered by the LPS-1.2 to keep the Ultracaps float-charged. Also phatter and better than the hybrid cap, but I still preferred the 2 UCPi in the manner I generally use them. Next is to try fairly large polyprop film caps (100uF or so) before or after the UCPi.

Curious to hear your answers to my question on this DAC project and any suggestions you might have.

Greg in Mississippi