[JaMo]

Just about everything I read, including from the designer, agrees with that. I emailed Kingwa to ask how the nfb7 with the new opa+transistor serve psus compare to the r2r now as the new psus are described as improving soundstage, detail, and dynamics. I'd expect the superior detail soundstage and transparency to equate to speed in the circuitrys ability to get all that information out. Perhaps just the nature of the resistor ladder vs the ds chip is enough of a delay to describe it as slower? But in the end r2r results in a more natural presentation.

I wouldn't say that R2R are slower here. Earlier they may be known to be more soft and laid back, but now they are just brilliant in Kingwa's newest designs. I listen to almost every kind of music but have a weakness for acoustic, clean recordings, voices. But not to worry. The R2R, at least with DA7- and DA8-modules from Kingwa handles it all without effort. A very nice bonus is the fact that they also can handle DSD material. Whatever I "throw at the dac" sounds amazing...

Jan

 

[DACLadder]

It has been one week since installing the DA7 V2 DAC modules and over 5 weeks on the Accusilicon upgrade. Part of the deal with Kingwa and the recent upgrade offer to V2s is that we discuss. Sure! The V2s are balanced with more transparency over V1s. More depth to the sound. Less grain. Vocals are clean, lots of detail, and very dynamic. DA7 V1s are "shouty" in comparison. Shouty in that when volume was high on loud music passages the V1s accentuated the upper mid-range and lower treble glare. In other words the V1s were harder sounding on loud passages. Much better now with V2s but still dynamic! The Accusilicons help with grain/ glare as well.

I admit that I am "shell shocked" in that I have introduced four upgrades and every few weeks declare "best sound ever" from the R7. That has not changed and each upgrade compliments the other. Overall grain has reduced tremendously. Much more detail and nuance. The changes are running together so I reviewed my prior comments. To recap....

TDA Asy - This firmware was suppose to level sound quality between inputs. With DA7 V1s and standard XOs I found though that magic did not really happen until I had the Gustard U16 HDMI I2S connected. Asy did not have the quite the same affect with the SIngxer F1/SU-1. Even length of the HDMI cable affected sound with Asy. I go by what sounds best and Gustard U16 and Asy is a good combination (very short HDMI cable). TDA Asy works better after the Accusilicon upgrade. Asy is not laid back on my R7.

Accusilicon XOs. - Major upgrade. Week1 had a lot of variability in sound. Good highs one day and strong bass the next. Sondstage comes and goes. Week 2 the DAC started to disappear. More transparency, detail, and accuracy. I could start to push volume higher as grain/glare began to recede. At a fixed volume level the R7 did not seem as loud but I could see the same amount of power delivered to the headphones. Pushing volume up slightly balances the sound and definitely more power driving the phones but no ear burn. Similar experience with the M7S upgrade to Accusilicon.

DA7 V2s - Immediately had better balance, less grain, and less upper mid-range glare. More depth to the sound (transparency). Vocals excellent. After 4 days sound is balanced with plenty of bass (I like plenty of bass) and mid-range textures. Great compliment to the Accusilicons XOs. The DA7 V2 DAC modules have been shipping with the R7/R8s since Dec. 2018. Us old timers are just slow at upgrading! I am sending back the old V1 modules to Kingwa.

Singxer SU-6 DDC - The SU-6 sounds great. Highs are silky and abundant. Good bass. Clean sound but not laid back at all. Balanced high to low. Still running in the SU-6 but think it will be great overall. The Gustard U16 sounds great as well.

I am happy that others are now upgrading. I would certainly like to compare a modded R8 with my R7. The R7 sounds like a different and better DAC. I sincerely hope these recent changes make the R8 sound better as well. My R2R 7 chassis is really old (2 yrs) and could use an upgrade or two. So maybe I had farther to go to catch up with current production. And I have no regrets with any of these upgrades. Each one has positive affect with great synergy.

I still have issues using DSD over HDMI I2S. Same with SU-6 and similar to the Gustard U16. The Singxer F1 on IN6 plays DSD OK before and after all mods. I reported to Kingwa. I am 99.9% PCM so all my comments are referring to PCM.

Kingwa is amazing prolific over the past 2.5 years. Throughout the past year Kingwa released new firmware every 4 months that made the R7 sound better. I'm confident he is working hard to make his products better. Not sure my soldering iron can keep up with the upgrades!

 

[nikko510]

In my opinion, in this way, what I show in the pictures is better to exchange Accusilicon.

 

[Toni-Mang]

Could you be so nice and explain the difference to other methods shown here? Maibe a helpful information.

 

[nikko510]

Better to raise the board , just like you did it .
Then we have the certainty that we will not spoil anything at the top.

 

[Toni-Mang]

Thank you, i understand...i think clock switch might be the first level to the v2 boards

 

[DACLadder]

@nikko510 Nice job! How hard was it to reroute the I2S wiring bundle to the DAC modules and pull up enough slack to avoid unsoldering? Clever approach and good skills.

 

[nikko510]

I desoldered only these two entrances.The rest can be unscrewed.

 

[ToddRaymond]

For what it's worth, I am thus far also a very happy SU-6 customer. I am unfortunately unable to offer up any comparisons versus other digitial-to-digital converters, but it's a considerable step up from the Amanero board in my R-28, and so far it's been 100% reliable.

 

[FredA]

I desoldered only these two entrances.The rest can be unscrewed.

Dam! After removing the separators, there is obviously some loose. So easy i have got to install the new xos tomorrow!

Thanks so much! I will do the da-7s later!

Fred

 

[JaMo]

Dam! After removing the separators, there is obviously some loose. So easy i have got to install the new xos tomorrow!

Thanks so much! I will do the da-7s later!

Fred

Ha ha... I know the feeling. Couldn't resist to solder in the XO's in the 27.77 a few moments ago..They were rather easy to unsolder and pick up from the top.
/Jan

 

[DACLadder]

I desoldered only these two entrances.The rest can be unscrewed.

I see... unsolder the I/O wires at the chassis connectors. You method is similar to Jamo's where the board is tilted up.

Let me see if I can give short summation of the procedure.
1. Remove top cover. Remove chassis wall dividers (2) separating the analog and digital boards. Set aside.
2. Unscrew USB and I2S daughter boards from the back I/O panel. If these boards are hard soldered to main board then wrap and secure the boards to the main board out of the way. If the boards are plugged in disconnect and set aside.
3. Unsolder the wire connections from digital board to the back I/O panel. Unsolder wires at the connectors for easier access.
4. Uscrew the digital board from the chassis mounts (6 Philips screws i think).
(JaMo unsoldered the 8 I2S feed wires at the digital board here. nikko510 leaves them connected)
5. At the back panel end of the digital board slowly pivot the board up The power supply side of the digital board still has wires connected on the bottom side. Take care to avoid pinching or straining wires. When enough bottom side access is achieved use a prop to hold the digital board in place.
6. From the bottom side of the digital board unsolder the old oscillators and resolder new ones in place. Double check oscillators are correctly installed.
7. Repeat steps in reverse for reassembly.

 

[FredA]

I see... unsolder the I/O wires at the chassis connectors. You method is similar to Jamo's where the board is tilted up.

Let me see if I can give short summation of the procedure.
1. Remove top cover. Remove chassis wall dividers (2) separating the analog and digital boards. Set aside.
2. Remove USB and I2S daughter boards and set aside.
3. Unsolder the wire connections from digital board to the back I/O panel. Unsolder wires at the connectors for easier access.
4. Uscrew the digital board from the chassis mounts (6 Philips screws i think). Disconnect front panel control cable.
(JaMo unsoldered the 8 I2S feed wires at the digital board here. nikko510 leaves them connected)
5. At the back panel end of the digital board slowly pivot the board up The power supply side of the digital board still has wires connected on the bottom side. Take care to avoid pinching or straining wires. When enough bottom side access is achieved use a prop to hold the digital board in place.
6. From the bottom side of the digital board unsolder the old oscillators and resolder new ones in place. Double check oscillators are correctly installed.
7. Repeat steps in reverse for reassembly.

That't what i figure except i don't think disconnecting the front panel cables is needed. I sure hope it's not as mine are soldered and covered with glue...
E front

 

[nikko510]

It is not necessary to disconnect the cables on the front panel.

I am waiting for new software TDA Asy I2S in4 R2R 7 .

 

[DACLadder]

That't what i figure except i don't think disconnecting the front panel cables is needed. I sure hope it's not as mine are soldered and covered with glue..

After thinking about it the control cable should pivot up no problem. I deleted the step in my original post. Good luck!

When all said and done I will rework all my DACs with this method. Looks very straightforward.