[Ian S]

@Xoverman "very rewarding to add 4 tant capacitors across the XILINX ( USB side ) bypass capacitors".

Did you try that? Which caps did you change?

I'm just probing the board now to try and identify which MLCC to swap to tant poly.

Instead of 22µF MLCC for the Set cap near the XTALs, should I fit tant poly 22µF? Was there an audible improvement?

Have you tried sticking damping pads to the case on the SU-6 to reduce vibrations?

Which pins did you join that 100µF cap that's bent over near the white socket for the front panel display? Did that make a difference?

Did you find the way to set your PC and SU-6 to Asyncronous? I saw in the SU-6 driver (I have 5.12) that the input & output latency are about 45ms. And ASIO is not active.

 

[Xoverman]

@Xoverman "very rewarding to add 4 tant capacitors across the XILINX ( USB side ) bypass capacitors".

Did you try that? Which caps did you change?

I'm just probing the board now to try and identify which MLCC to swap to tant poly.

Instead of 22µF MLCC for the Set cap near the XTALs, should I fit tant poly 22µF? Was there an audible improvement?

Have you tried sticking damping pads to the case on the SU-6 to reduce vibrations?

Which pins did you join that 100µF cap that's bent over near the white socket for the front panel display? Did that make a difference?

Did you find the way to set your PC and SU-6 to Asyncronous? I saw in the SU-6 driver (I have 5.12) that the input & output latency are about 45ms. And ASIO is not active.

for the XILINX and digital IC's just put the Tantals on top.

"Instead of 22µF MLCC for the Set cap near the XTALs, should I fit tant poly 22µF? Was there an audible improvement?" <-- Yes !!
You have to use ultra low leakage capacitors !!!

100µF is across the USB Power

"SU-6 to Asyncronous?" I just installed the Driver

 

[volikovvv]

Hello everybody, currently my desktop setup is USB from PC to Chord mojo 2 to RCA inputs Jotunheim 2, i hear huge difference between desktop pc, laptop, smartphone, and I'm trying to find a solution to have good digital transport to feed chord mojo from desktop pc and laptop, i want them to sound the same)) I thought to purchase SU-6, and connect pc to su-6 and then via coax to mojo 2, i listened multiple dac's in 700-900 range and found that mojo 2 sounded more natural to me than others, but poor digital input disturbing me. Is it a good option to go in my case?
p.s. to headphone amp collection, i plan to add schyt lyr+..

 

[br4lin]

Hello everybody, currently my desktop setup is USB from PC to Chord mojo 2 to RCA inputs Jotunheim 2, i hear huge difference between desktop pc, laptop, smartphone, and I'm trying to find a solution to have good digital transport to feed chord mojo from desktop pc and laptop, i want them to sound the same)) I thought to purchase SU-6, and connect pc to su-6 and then via coax to mojo 2, i listened multiple dac's in 700-900 range and found that mojo 2 sounded more natural to me than others, but poor digital input disturbing me. Is it a good option to go in my case?
p.s. to headphone amp collection, i plan to add schyt lyr+..

yes, this is what I have currently have. I would beware of the coax adapter and cable you use, they are all pretty cheap so you might as well try a few. That aside You will also gain the ability to have volume control digitally on the computer side which is pretty convenient.

 

[schuuu]

Could someone point me to the official Singxer USB drivers for Windows XP 32-Bit?
Singxer.com only lists v3 upwards.

I reckon I need v2 for the Xmos-208 chip.

 

[Ian S]

I have fitted the rest of the parts I had.

Modified the 3045 board to utilise PGFB, cutting the track from Input to 7 fitting the two resistors.

And fitted a 22µF X7R MLCC for the Set cap instead of the 4µ7 that was there. I had a 1210 which is a bit big. I fitted a small copper rod (cut component lead) from the via to earth, across the end of the cap so it's not just solder there.

Fitted the 717 chips to the Singxer main board, removing the NC pins.

Increased the cap at the PSU 7.5V socket to 2200µF. Moved the 820µF I had there onto the pins of the regulator near the front of the board..

I fitted the two Set caps for the Xtals, inside the alu black box. Bought X7R.

Fitted 11 Tant Poly caps. I bought small ones that were the same size as the OE MLCC. Larger size seem to have lower ESR but bought what would more easily fit.

Fitted the 3045. With all that ground plane there below the OE chip, next time I'd leave the blue boards middle pin on the front and bend the end backwards.

Did it all change the sound quality? YES

The two Xtal 22µF cap, as Xoverman said, increase the coherance and dynamics. Well worth doing.

Seperating the USB socket from the 'clean side' and the other things at that time, did seem to give more good bass. Also a good improvement in dynamics.

Fitting the 717's and the tants, that sound very wrong at first listen, terrible really, was a lot better by the next day, maybe 12 hours non stop playing. The following day, non stop playing, better. After that very good. Clean clarity, coherence, dynamics, imaging width, depth, placement (with loud speakers). As @b0bb said, give it some playing time before critical listening.

The LT3045, same as Xovermans said, cleaner, better. Was dull at first listen, maybe it takes a while, 24 hours? for the clocks to thermally stabilise? After then, great sounding.

General sound quality from my system is now so much better than it was. Maybe every SU-6 owner should modify their's or get it done.

Thanks so much for all the suggestions, recommendations, advice, in this thread.

@Xoverman How much more improvement did you get from the other LT3045 you fitted, compared to the 'main' one? Is it worth the cost and difficulty to add those? Did those extra caps across your I²S socket caps improve it? Anything else?

I've not done the sand filling yet.

How about wool felt sheet under the main board, on the bottom chassis plate, would that help with the acoustic vibrations affecting the high frequency, 45MHz, would it overheat the Xtals?

 

[Ian S]

Singxer SU-6 materials:

2 x IL 717VE
390-IL717VE-ND
DGTL ISO 6000VRMS 4CH GP 16SOIC. Get the V version not the -3 version as -3 is a smaller sized chip.


1 x IL711-3E
390-IL711-3E-ND
DGTL ISO 2500VRMS 2CH GP 8SOIC.


2 x TV1625-3R0256-R
283-TV1625-3R0256-R-ND
Eaton. 25 Farad, 3 Volt, Super Cap. 18mΩ.
Replacing the two 15 Farad supercaps. Slighter wider pin spacing that the originals.


3 x RNL1C222MDS1PH
493-16395-1-ND
CAP ALUM POLY 2200UF 20% 16V. 8 mΩ. 810 mA @ 120 Hz. 8.1 A @ 100 kHz. Is up to 9 Volts across them.


7 x RNL1C821MDS1
493-16381-ND
CAP ALUM POLY 820UF 20% 16V. 8 mΩ. 750 mA @ 120 Hz. 7.5 A @ 100 kHz.


1 x RR71C101MDN1
493-3716-ND
CAP ALUM POLY 100UF 20% 16V. 7 mΩ. 560 mA @ 120 Hz. 5.6 A @ 100 kHz.


12 x T58MM226M6R3C0300
718-2113-1-ND
CAP TANT POLY 22UF 6.3V 0603
11 for replacing various caps. And one for the Set pin on a 3045 regulator.


1 x T529P476M006AAE150
399-12351-1-ND
CAP TANT POLY 47UF 6.3V 0805
For replacing cap by pin one of the FGPGA.


2 x GRM21BZ71A226ME15L
490-GRM21BZ71A226ME15LCT-ND
CAP CER 22UF 10V X7R 0805
For replacing the two SET cap for the 3042 regs for the two Xtals.


1 x ERA-3AEB4992V
P49.9KDBCT-ND
RES SMD 49.9KOHM 0.1% 1/10W 0603
Adding PGFB for a 3045 regulator.


1 x RT0603BRD07453KL
13-RT0603BRD07453KLCT-ND
RES SMD 453K OHM 0.1% 1/10W 0603
Adding PGFB for a 3045 regulator.


1 x USBR-B-S-S-O-TH USB2.0 type B.
SAM8891-ND
Samtec Inc. USB-B (USB TYPE-B) socket, Shielded, gold finished contacts.
For replacing the USB socket


LT3045 Low noise RF DAC upgrade from 78XX. 3.3 Volts.
https://www.aliexpress.com/item/4001180261348.html?spm=a2g0o.order_list.0.0.21ef1802YHxKg8
Huo Guang Store
Module from Ali Express. Or for more money, make your own from chip, board & parts.
EN/UV to input.
Leave PG open.
Tie ILIM directly to GND.


1 x X7R MLCC 22µF 16V 1210.
Farnell 2781419
For Set cap on 3045 module. A bit too big, I made a wire link across the end from the via. 0603 is about the right size, 0805 might fit OK.


Solder: Stannol KS115 TSC Flowtin Sn95.5 Ag3.8 Cu0.7. Eutectic alloy. But this one can be a difficult to use as it can not flow well enough.
Chemtronics circuitworks CW8100 no clean Flux pen. I did clean though.
IPA and cotton buds, kitchen roll, for cleaning the flux residue. Specialist Flux cleaner might be a bit better?

 

[kingoftown1]

@Ian S thanks for providing that level of detail on both parts lists & pics!

 

[crazyclif]

Does anyone have a pic of there pin setting when set up with a denafrips pontus 2

 

[Ian S]

If anyone with an SU-6 also has ground boxes in their system, I'd really recommend trying connecting one to the SU-6's chassis ground. It's easy to do using the screws that hold the AES xlr output.

Ah, just saw this when I searched for Pontus 2 switches, seems that PS Audio positions are suggested.

Not tried grounding the chassis yet. Have had great effects before from doing that with PC cases when we used soundcards. Scale of effect varried a lot in each firends home, I guess each had different quality of earthing, cross bonding, earth rod into the water table, etc.. Did get some effect here but not much. I have a big super spur from the meter board, fuse board, and a 10mm² earth wire, but at about 20 metres that might be to thin to transfer away the HF noise. I was wondering if a decent diameter copper enamelled Litz might work better, direct to an earth rod, but the cost of that length of it has made me pause.

I did unplug the Singxer supplied mains lead, that here goes into a trailing block (6 way sockets on a lead) from the Singxer PSU and pushed the PSU onto a 10mm² lead that's direct wired to my super super, and like many here have said, the sound changed. But for me it was shrill, emphasised the upper mid in a not good way. Went back to the thin lead into the plugs block and was smoother, more bass, better tonal balance, easier to listen to, but maybe less incisive presentation. So, I wonder why, if the PSU has no earth connection, it's only the L & N that convey anything in either way.