[DACLadder]

Hi all. Hope someone is able to help.

I have been trying to get my old optical module to work on my digital 2019 board. No success.

My optical is from the original M7 and need 5v to work? Old reciver look like RX177L.

The new board have 3,3v. Do I need a new optical module?

Is it possible to change the parts on the old module. What parts do the new module contain? What RX is the new reciver?

You are correct the old M7 optical board uses a higher voltage in operation. Kingwa could sell you a new adapter board and would be cheap I'm sure. He may be able to tell you how to modify the 5V version for 3.3V use.

 

[sazzz]

Once again clearing the dust from my master7, I noticed the connecting wire between the HDMI board and the digital board. It seemed to me excessively long and rather flimsy. It seems to me that the simplest ordinary cable was used, like a generic wire with standard length of 10 cm. I made several attempts to replace it with shorter cables, using different types and cross-sections of copper wires and found that replacing this cable can significantly affect the sound. I advise you to try, the changes can be quite noticeable. Perhaps this tweak has already been mentioned in the topic.

 

[sajunky]

I suggest to not replace a stock cable if you don't know pinout and purpuse of individual wires and have no required knowledge. Cross-section no matter to some level, but interaction of individual wires do. By example, a 'standard' ribbon cable can work better as it has an uniform impedance over the entire lenght.

 

[DACLadder]

@sazzz Look below for HDMI adapter connection (+3.3V) in the old M7. The adapter board is my own design but the installation guide shows where/ how to pick off 3.3V and GND. And the four I2S signals are labeled on the main board. The 5V version is intended for other products. This just my project archive but you are welcome to look. 10cm signal wire length is about right and chose to not use a ribbon cable to avoid crosstalk. See Picture 7 in either guide.

Kingwa used this basic circuit for his products. Different parts but similar circuit. If it gives you any ideas… great! And if you have questions let us know.

On the later Singularity digital board power and signals connect on the same 7-pin header connection. The header pins are well labeled.

https://onedrive.live.com/?id=636DC4E8060D66A1!358&cid=636DC4E8060D66A1

 

[sazzz]

@sazzz Look below for HDMI adapter connection (+3.3V) in the old M7. The adapter board is my own design but the installation guide shows where/ how to pick off 3.3V and GND. And the four I2S signals are labeled on the main board. The 5V version is intended for other products. This just my project archive but you are welcome to look. 10cm signal wire length is about right and chose to not use a ribbon cable to avoid crosstalk. See Picture 7 in either guide.

Kingwa used this basic circuit for his products. Different parts but similar circuit. If it gives you any ideas… great! And if you have questions let us know.

On the later Singularity digital board power and signals connect on the same 7-pin header connection. The header pins are well labeled.

https://onedrive.live.com/?id=636DC4E8060D66A1!358&cid=636DC4E8060D66A1

Thank you. Not sure if I will be able to assemble the board. I was tempted to try alternative HDMI receiver boards, but most of them are 5v versions. And I don't know where I can take 5v on my old m7 digital board, maybe you know?
About internal cable - for now I've tried many variants and got the best result with thick cat8 cable with 22 awg mono copper wires pairwise connected (and shielded) for 4 signal connections. It gives more resolution, depth and bass in comparison with stock ribbon.
Yes, I understand Kingwa uses common things for internal connections in this case but the digital and analog boards on m7 connected with more decent copper wires as well as input-output connectors.

 

[DACLadder]

I think the optical adapter is supplied 5V in the old M7. I’m sure other parts as well. But if you don’t use the optical input just re-purpose the main board 3-pin optical connector to grab 5V and GND on two of the pins. At least you have more options this way.

 

[sazzz]

You are right, i should grab 5v from optical input, i never used it. thanks!

 

[DACLadder]

Kingwa is offering for a limited time Master S7 and HE-7 2021 DACs for sale. They have the latest features like external 10M clock input and isolated USB/HDMI inputs. Many other features like sampling rate display on the front panel and the USB input runs synchronously.

I have the current R7HE Mk2 DAC with the same basic features. It is just awesome with a good quality 10M clock. All inputs sound better than previous generation.

http://www.audio-gd.com/R2R/M721/M721EN.htm
http://www.audio-gd.com/HE/HE721/HE721EN.htm

 

[DACLadder]

Kingwa sold me a 2020 version of the singularity digital board. I replaced the Singularity 7’s 2017 board with the 2020 version. This gives 10M capabilty without the need to also upgrade the I/O boards as required if I were considering the 2021 digital board variant. So I can keep the Singxer F1 on IN6 and the custom HDMI adapter. I did not upgrade the faceplate that automatically sets the input clock to internal XOs if ext. 10M clock is bad or not detected. Instead just use a jumper on DSP jumper IPS0 to select int/ext clock. If external clock is missing you just get no sound output when the jumper is in place. With the board swap IN3 becomes a 10M clock input.

Why did I do this? My other pcm1704 DAC (M7S) is broken and my fault from years of experimentation. It just stopped working in the middle of the night. So I will take the S7’s board removed yesterday and install in the M7S. Kingwa has a few of these older type boards but has moved production to less costly digital board as seen in the latest MK2. The old boards have a limited availability and acted before they disappeared.

If you are considering a DAC purchase then please take a look at the newest Mk2 R2R DACs. The R7HE Mk2 is just awesome especially with an excellent 10M ext clock. It takes sound to levels unobtainable with these pcm1704 DACs. Not by a small amount but in leaps. I still love these old DACs but they are no match for the R7HE Mk2.

 

[tumpux]

Whoaaa, this is the first time I heard someone said that the pcm1704 board is not better than the current r2r board.

 

[sajunky]

Hmmm, to many DAC's... Since I got R2R-11, I didn't touch my Nobsound 8xTDA1387. But now when R2R-11 is on a loan, Nobsound is not bad at all. It is only $42.

 

[FredA]

Whoaaa, this is the first time I heard someone said that the pcm1704 board is not better than the current r2r board.

I have the same opinion. The da7 have better neutrality and highs. The 1704k is charming, a little euphonic. For ultimate imaging/sounstaging and the most analog sound, the da7 is the way to go. However, the 1704k is certainly one of the best if not the best r2r chip ever made. Some could still prefer it, depending.

 

[DACLadder]

Fred is correct. The M7s have the ‘warmth’ veil where the Mk2 is transparent and much more detail/ depth. Excellent bass/ highs. It’s intoxicating after evolving over the years on the Ref 5, M7s, and R7. The R7HE MK2 is Kingwa’s best DAC so far that I have heard. I say that with no hesitation.

Be fun to compare the latest HE-7 2021 to the R7HE Mk2. Closer in technology. But totally understand pcm1704 love.

 

[PeterCraig]

This is where you are waiting for Kingwa to step in here himself and drop his opinion into the discussion

 

[DACLadder]

I changed the S7 supplied Dop1.1 firmware back to the original 2020 f/w Nov. 2019. The S7 is kicking butt now! Very dynamic and smoother in the highs. I don’t like the the latest firmware on the M7S either.

External clocking the Singularity 7 (M7) analog hardware has turned into smiles and no disappointment. Shame these elite 10M clocks cost more than the DAC but Kingwa’s proprietary clock synthesizer code really works. All my gushing about the R7HE mk2 is strictly from external clocked point of view. And the S7 benefits as well. Recommended upgrade if you have a good 10M clock like a Morion mv89 or better.

I would say Kingwa’s 2021 pcm1704 models would be outstanding. Wish I could trade up especially to the HE version.