Thanks Ian,
The I2S signal from the fifopi/reclocker is transferred into simultanous mode and also an inverted signal is created; for each channel a stereo dac chip is used in balanced mode (this cancels out all common mode and ground noise) and the IV dac output is connected directly to a Sowter IV transformer.
I use 2 stereo dac chips per channel in parallel; 4 in total.
This is the most musical involving dac I have ever built and heard, while also being very resolving, detailed and analog sounding.
It betters all the other TDA1541A dacs I built, all dddacs I built, and now it is residing next to the awesome new ladder dac from Andrea and it still is more musical involving.
I made a power supply with mosfet rectification, Black Gate non polar capacitors and Sparkos labs regulation. I also experimented with other types like LT regulators, battery supplies and a new class D power supply. But this one is the best performer of them all.
Dear Ian, I know very well what you're going through with the Spring 3.. I'm afraid you won't be able to fully compensate its character with higher quality input, because S3 is a flawed design internally. Therefore the sound will probably always remain non-neutral, kind of hyped / over the top.Try to improve R-2R Holo Spring3 sound quality by HdmiPiPro and FifoPiQ7 (1)
I’m interested in the sound of a NOS R-2R DAC, so I bought a Holo Spring 3 last month. After three weeks break in, I have to say I like the sound more and more.
The output voltages of Spring 3 are RMS 2.9V/RCA and 5.8V/XLR, so the sound levels are a bit higher than standard DAC output levels which are RMS 2V/4V.
Spring 3 is a typical NOS R-2R but with higher accuracy than many others because of the compensation technology.
The sound is very impressive but the style is different from the popular Delta-Sigma DAC, with great transparency, higher density, more details and dynamic, more natural. The 3D image is very solid. The sound is also very clean because of the black background. Those are typical R-2R DAC sound signatures. Spring 3 could be the best R-2R DAC at this price range.
However, when comparing with my well running-in FifoPiQ7/9038Q2M Dual Mono/OPA861I/V DAC system (With 90/98MHz OCXO), What I’m not happy with is that the 3D instrument image of the Spring 3 was pretty big so the whole soundstage was not that pin-point focused and delicate. I will also feel a bit tired after listening to it for a longtime.
Spring 3 uses an internal PLL as the audio MCLK, I believe that could be the reason. Fortunately, Spring 3 has an I2S/DSD over HDMI input option, so I’m wondering if I still have a chance to improve the sound quality of my Spring 3 by feeding better external I2S/DSD signals with higher grade clock to it.
I’m gonna try my new flagship FifoPiQ7 + HdmiPiPro + MonitorPi + PurePi ultra-low jitter network streamer transport solution with my Spring 3.
Somebody said that the R-2R DACs are immune to clock jitter, but it could be not true.
https://github.com/iancanada/DocumentDownload/blob/master/HDMIpi/HdmiPiPro/HdmiPiProManual.pdf
https://github.com/iancanada/DocumentDownload/blob/master/FifoPi/FifoPiQ7/FifoPiQ7Manual.pdf
https://github.com/iancanada/DocumentDownload/blob/master/MonitorPi/MonitorPi.pdf
Spring3HdmiPiPro by Ian, on Flickr
If you really want to keep it, I've had success with using aftermarket pads for S3, specifically Maxi from AAI.SK, which helped to stabilize S3 not only mechanically, but also electromagnetically. The resulting sound was much more relaxed, neutral, but also focused and clearer. But still not completely neutral.
Anyway, if you're willing to take some advice, then as soon as this honeymoon period is over, I would file for divorce and look for some really neutral DAC, for pleasant long-listening sessions.
UcConditioner 3.3V doesn't have enough voltage to drive a blue LED, so has to use other colors. Please just no worries about that.
Hi Ian,
Are you using OPA861 as an open loop (OTA) I-V fed by Dual Mono 9038Q2M into Emitter port?
Terry
I had to ask since all the other LEDs were symmetrical. Now I know. I noticed late last night my current build has some rather low-level harsh crackling noise coming through the speakers with ears pressed. Very noticeable. It's not hum, just junk noise. I have no idea what it is, or where it's originating from. Will try turning off some external variables in my shop first to see if that makes a difference.
@ Terry Demol
Yes, OPA861 balanced I/V works with zero feedbacks. Schematic is here:
Or you can read the user's manual for more details.
https://github.com/iancanada/DocumentDownload/blob/master/RPiDacHAT/IVboards/OPA861IV/OPA861IV.pdf
OPA861BalancedIV by Ian, on FlickrIan
Hi WladimirMXP
I have already noticed something of Spring 3
1. After running Spring 3 for a long time (a couple of days), I have to turn off the power and turn on it again to reset the internal compensation, otherwise the sound quality can be degraded a little bit.
2. I use IsoAcoustics on Spring 3 for now.
My HdmiPiPro / FifoPiQ7 solution works for all DACs with I2S over HDMI input. I'm interested in testing other ones with great sound quality. Please let me know if you have recommendations.
Ian
Hy Guys
I need help to solve this:
I have a rPi with FifoPiQ3 and I'm trying to connect it to a Buffalo II DAC
Buffalo II have I2S input named:
D2 = Source Data
D1 = Source Word Clock(LRCK)
DCK = Source Bit Clock
FifoPI Q3 have:
SCK
LR/D0
SD/D1
Now, this is probably a stupid question, but...how I have to connect the BII ?
I need help to solve this:
I have a rPi with FifoPiQ3 and I'm trying to connect it to a Buffalo II DAC
Buffalo II have I2S input named:
D2 = Source Data
D1 = Source Word Clock(LRCK)
DCK = Source Bit Clock
FifoPI Q3 have:
SCK
LR/D0
SD/D1
Now, this is probably a stupid question, but...how I have to connect the BII ?
No, my reasoning is that a clock is a very stable load for a power supply and a shunt regulators main advantage will therefore not be needed. A serial regulator would be preferable due to the high power supply rejection rate they can deliver (the Sparkos has -125dB psrr) this is needed when you want the low phase noise of the clock not to be masked by ps noise.
The question is to know,Why a regulator is better than a battery (A123)known to be low noise.
I tried the A123 batteries, they were not the best ps for the clocks. Batteries have chemical noise, they are not more silent than line power. And another thing of importance; clocks need to be turned on constantly for best performance, this is in conflict with the loading cycle the batteries need.
@Supersurfer, there used to be a post on DIYAUDIO showing the noise level of Lipofe cells to be below -150dB, which obliterates most active regs.
Hi all,
Today I spent some time comparing the RPi/Allo Kali Reclocker/DDDAC/Transformer output, with the RPi/FifopiQ7/Mono DAC/OPA861.
DDDAC: ( http://www.dddac.com/ ) (1794 NOS DAC)
My findings regarding the sound quality so far is that the DDDAC sounds somewhat more detailled and more open. Of cause as far as I 'am able to judge.
I 'am wondering wether a transformer output on the Ian mono dac would be an improvement. Now I use the opa861 board.
Also could the Dual Mono ES9038Q2M DAC be programmed with the ESS SABRE 90X8 controller to act as the 1794. Or to approach these characteristics.
Does anyone have any similar comparison material?
rgrds, Jan
Today I spent some time comparing the RPi/Allo Kali Reclocker/DDDAC/Transformer output, with the RPi/FifopiQ7/Mono DAC/OPA861.
DDDAC: ( http://www.dddac.com/ ) (1794 NOS DAC)
My findings regarding the sound quality so far is that the DDDAC sounds somewhat more detailled and more open. Of cause as far as I 'am able to judge.
I 'am wondering wether a transformer output on the Ian mono dac would be an improvement. Now I use the opa861 board.
Also could the Dual Mono ES9038Q2M DAC be programmed with the ESS SABRE 90X8 controller to act as the 1794. Or to approach these characteristics.
Does anyone have any similar comparison material?
rgrds, Jan
Thank you very much Ian, BII is working fine with FifoPiQ3 (with CCHD-957 45 and 49Mhz XO)
Does it have any meaning to detach the BII XO and feeding it with FifoPi MCK ?
I've read somewhere that I can isolate the BII XO removing a ferrite bead L7 and soldering MCK to R17 pad. Seems quite easy
Feed MCLK to BII to run the ESS DAC at SYNC mode can make a great improvement to the SQ. That's what we did for many years.