[FredA]

I am in NOS3 and not 6moon setting. However, I thought that hissing was gone, but it actually is only lowered since I replace the wires, it is still hissing

Sure it's not in the recording? Also, brand new wires can sound like crap for a while. Occ, most especillay. Perhaps you should try the r2r 7 in another setup.

Did you turn it off before changing the jumpers?

You symptoms sound like there is an impedance problem somehow.

 

[Whitigir]

I've had a Holo Spring Level 3 dac. The R2R 7 really performs way better in my system. It has a lot to do with matching in the set is seems.

Probably, but there is no system that can outperform my Stax sr-009 and KG T2. So if matching can reduce Hiss, and bass/warmth, then I will just have to buy holospring instead.

We even compared back to back. The holo spring has ways better black background in comparison and transparency, clarity is beyond lks004 without messing with it

 

[Whitigir]

Sure it's not in the recording? Also, brand new wires can sound like **** for a while. Occ, most especillay. Perhaps you should try the r2r 7 in another setup.

Did you turn it off before changing the jumpers?

I wouldn’t make such newbies mistakes like that. Ofcourse it is turned off before any messing stuff goes on

 

[FredA]

Sure it's not in the recording? Also, brand new wires can sound like **** for a while. Occ, most especillay. Perhaps you should try the r2r 7 in another setup.

Did you turn it off before changing the jumpers?

I wouldn’t make such newbies mistakes like that. Ofcourse it is turned off before any messing stuff goes on

Just checking. Sorry. The hissing could go away with burn in as the r2r ladder stabilizes. Resolution will increase and the problem could go away. The need for extended burn in is no joke.

 

[FredA]

As a reference, the r2r 7 is the most resolving dac i have had in my setup by a clear margin. But again, at first it sounded not so good at times. Then superbly for a few days. Then bad again. But now it fluctuates a lot less. I am at the point my hearing fluctuates much more than the dac.

I believe the circuits are complex and burn in takes longer as a consequence.

 

[Whitigir]

As a reference, the r2r 7 is the most resolving dac i have had in my setup by a clear margin. But again, at first it sounded not so good at times. Then superbly for a few days. Then bad again. But now it fluctuates a lot less. I am at the point my hearing fluctuates much more than the dac.

I believe the circuits are complex and burn in takes longer as a consequence.

Technically speaking, burn-in can further improve what is already there, but hissing is something not working properly.

About the holospring, it has more transparency and clarity than my lks004, with deeper soundstage as well. The r2r7 out of the box is 5x worse than my lks004 in clarity and transparency but boom and bang, and that was why I got disappointed, couldn’t help to put silver in it to control it down. Yet, even in stock form it hisses, after the silver wirings are in, it only hisses less.

Recording wouldn’t be the issue because neither holospring nor lks004 have such problem. I may have defected unit, or the r2r7 is what it is and not my taste or whatever for my system. We will see what AudioGD has to respond to this. After the upgrades wires, I love the tonal body better than holospring or lks004, just can’t deal with hisses.

 

[FredA]

Technically speaking, burn-in can further improve what is already there, but hissing is something not working properly.

About the holospring, it has more transparency and clarity than my lks004, with deeper soundstage as well. The r2r7 out of the box is 5x worse than my lks004 in clarity and transparency but boom and bang, and that was why I got disappointed, couldn’t help to put silver in it to control it down. Yet, even in stock form it hisses, after the silver wirings are in, it only hisses less.

Recording wouldn’t be the issue because neither holospring nor lks004 have such problem. I may have defected unit, or the r2r7 is what it is and not my taste or whatever for my system. We will see what AudioGD has to respond to this. After the upgrades wires, I love the tonal body better than holospring or lks004, just can’t deal with hisses.

About replacing the digital connection between the r2r boards and digital, Kingwa told me the wires are impedance-matched to the boards for optimal digital transmission. I believe you need 75 ohms. Contact Kingwa to confirm. See this link for technical reference:

https://books.google.ca/books?id=Wv...nepage&q=digital connection impedançe&f=false

 

[Whitigir]

About replacing the digital connection between the r2r boards and digital, Kingwa told me the wires are impedance-matched to the boards for optimal digital transmission. I believe you need 75 ohms. Contact Kingwa to confirm. See this link for technical reference:

https://books.google.ca/books?id=WvAjvYLvOs8C&pg=PA27&lpg=PA27&dq=digital+connection+impedançe&source=bl&ots=dsvECPKqXU&sig=GmMMvqXBAges_isOYZ4HD1vbW8Y&hl=fr&sa=X&ved=2ahUKEwi3qZfnvNHaAhVCs1kKHfPJCz0Q6AEwDHoECAcQAQ#v=onepage&q=digital connection impedançe&f=false

Can you tell in more details ? Which wires are we talking about here ? The interconnect from USB modules into the processing board ?

 

[DACLadder]

I am in NOS3 and not 6moon setting. However, I thought that hissing was gone, but it actually is only lowered since I replace the wires, it is still hissing

Not to be snarky but if you want to sell (and have a 120v model) let me know. Do you hear hiss when tracks are not playing? Also do both channels sound identical (same bassy timbre)?

I can’t imagine that both analog channels would be equally defective in the same way. I sold an Yggy and MSB Analog DAC because they we’re light in the bass compared to the Singularity 7. But assume the R2R 7 was even more clinical and precise comparing to the S7.

For the Singularity digital board may want to turn it off and let it cool before restoring power to make sure it wakes up correctly. And always power off/ restart the box for jumper mode changes.

 

[FredA]

Can you tell in more details ? Which wires are we talking about here ? The interconnect from USB modules into the processing board ?

Specifically those you replaced in the second operation. They are running from the central (digital) board to the r2r modules. For the ones going from the usb module to the digital board, the same logic could apply (contact Kingwa) but the most sensitive connection is the former. There is no reclocking done by the r2r 7 boards, so anything that can mess up the transmission (timing wise) will have an impact on sound.

 

[Whitigir]

Specifically those you replaced in the second operation. They are running from the central (digital) board to the r2r modules. For the ones going from the usb module to the digital board, the same logic could apply (contact Kingwa) but the most sensitive connection is the former. There is no reclocking done by the r2r 7 boards, so anything that can mess up the transmission (timing wise) will have an impact on sound.

you are saying 4 inches of wire is 75 ohms ? I never heard such thing as wire impedance matching. Yes cables design as Coax have 50-75 ohms impedance design, but that is the whole cables....not wires....if wires have 75 ohms impedance, you may want to hook resistors in series instead of wires. Remember, silver wirings makes it hiss less, not more.

If a piece of wire is that much impedance, what do you think of soldering ? Lol

I am saying, for this design, everything is built in on the board.

Upgrade Wires only change conductivity as silver is 105% and copper is 100%, or OCC is 102.5% or so.

 

[FredA]

you are saying 4 inches of wire is 75 ohms ? I never heard such thing as wire impedance matching. Yes cables design as Coax have 50-75 ohms impedance design, but that is the whole cables....not wires....if wires have 75 ohms impedance, you may want to hook resistors in series instead of wires. Remember, silver wirings makes it hiss less, not more.

If a piece of wire is that much impedance, what do you think of soldering ? Lol

High-speed data transmission uses a transmission line whose impedance, given inductance and capacitance is measured at a reference frequency. See the link. The is electrical engineering stuff. You must have heard that digital interconnects, or coaxial cables in general, have a characteristic impedance, 75 ohms being the most common. Check the link i posted, the explanations are all there.

 

[FredA]

You can also check this link:

https://en.m.wikipedia.org/wiki/Characteristic_impedance

 

[Whitigir]

High-speed data transmission uses a transmission line whose impedance, given inductance and capacitance is measured at a reference frequency. See the link. The is electrical engineering stuff. You must have heard that digital interconnects, or coaxial cables in general, have a characteristic impedance, 75 ohms being the most common. Check the link i posted, the explanations are all there.

I know what you mean, and I am saying this is not what you think it is. Cables and the interface of given type of cables and input is different than Wires. For the record, I am not newbie

These are simply...Wires...the interfaces of whatever (magical dusts) needed would be built on into the R2R boards. There is no such thing as 4” length of wire that has 75 ohm impedance

 

[FredA]

I know what you mean, and I am saying this is not what you think it is. Cables and the interface of given type of cables and input is different than Wires. For the record, I am not newbie

These are simply...Wires...the interfaces of whatever (magical dusts) needed would be built on into the R2R boards. There is no such thing as 4” length of wire that has 75 ohm impedance

We are talking characteristic impedance, and this quantity is independent of cable length. Each transmission line, coaxial or not has one. Even traces in a pcb. As mentioned, this is stuff taught in electrical engineering. Characteristic impedance is important to consider in high-speed data transmission to avoid signal degradation caused by reflections. This is not trivial knowledge.