[DACLadder]

Kingwa just sent me R8_Asy3 firmware for R8, R8HE, and R27. See down a few posts.

 

[barbas]

Hi Scott, will the R7_Asy3 firmware work properly on my R2R7 (DA-7 V2 boards and Accusilicon)? Thanks and really appreciate your dedication to improve our user experience!

 

[DACLadder]

R8_Asy3 firmware for R8, R8HE, and R27 is available. But requires a hardware change (rework). I understand the reason for the change and am editing the instructions for clarification. Looks easy!

For I2S to function on R8_Asy3 two signals need to swap on the I2S internal cable. The reason for the change is to place I2S BCK signal on a dedicated FPGA clock resource pin. MCLK is now wired to the FPGA clock input but no longer needed with TDA firmware. FPGAs have dedicated pins for input clocks that vastly improves timing and speed through the FPGA. Otherwise you use general logic routing for FPGA clocks and suffers greatly. That's the technical reason for this rework. BCK is the important clock in Asy firmware.

The hardware change is not backward compatible to older firmware. So one-way journey unless you move the wires back. If the older R8 TDA firmware was using general logic routing for BCK then this change should be significant. A little pain for a lot of gain!

The rework is about as simple as it gets! Just swap MCLK and BCK wires on the I2S connector. See the "Upgrade_guide.txt", pictures, and R8_Asy3 firmware here. Enjoy and send questions as needed.
https://onedrive.live.com/?id=636DC4E8060D66A1!326&cid=636DC4E8060D66A1

And to be clear this rework is not needed on the R7/R2R 7 platform.

 

[517269]

The grid is so polluted with high-frequency noise, getting good sound has become tough, while 30 years ago it was so much easier. 3G, 4G, 5G. All this for what?

Vince Galbo of MSB put out a white paper on AC Power some years ago describing the relationship between AC wire resistance and the power amp drawing instantaneous current in response to the music demands.
Essentially, the AC voltage waveform gets clipped upon transient current demand of the amp. Depending on the AC wire resistance and the amplifier power supply demands, the harmonics generated back to the AC line are modulated by the music signal which feeds your front end components and even being re ingested by the amp itself.
I have voltage regulated Krell mono blocks fed by 60' of 10 AWG at 240VAC. According to Galbo's wiring chart, this should have been sufficient.
On a whim, I ran separate 6AWG feeds and shortened the runs by about ten feet. The result was a much more relaxed presentation, clearer transients and soundstage.
Not sure if this even applies to headphone amps, but just sharing my experience with the power amp as a major source of corrupted power and its effect.... For what it's worth.

 

[Tango Sierra]

Very interesting post. I did not know there were 3 regen. Makes me want to order the he9 even more. You have one if i am not mistaken? Would you recommend it with as much enthousiam as i do recommend the r7he? And do you find it neutral enough (it is supposed to sound rounder compared to the he1)?

It doesn't look like three regenerators to me. In the pictures, it looks like a larger transformer at the front in the regenerator section and behind that, the three normal R Core transformers we are used to seeing in our non HE units. Take this with a grain of salt as I am not an electrical engineer or even a repairman.

 

[DACLadder]

Hi Scott, will the R7_Asy3 firmware work properly on my R2R7 (DA-7 V2 boards and Accusilicon)? Thanks and really appreciate your dedication to improve our user experience!

Should work OK if you don't need input 4 I2S. The FPGA jumpers are remapped to accommodate the new R7 front panel but there is a guide to remap the jumpers. Download "R2R7settingguide.htm" and "R2R7setting.jpg" to a local directory and open the HTML file. The .jpg should display in the HTML page...
https://onedrive.live.com/?id=636DC4E8060D66A1!313&cid=636DC4E8060D66A1

 

[DACLadder]

It doesn't look like three regenerators to me. In the pictures, it looks like a larger transformer at the front in the regenerator section and behind that, the three normal R Core transformers we are used to seeing in our non HE units. Take this with a grain of salt as I am not an electrical engineer or even a repairman.

The big transformer (near front panel) feeds the three HE regenerator supplies in the next compartment toward the rear.

 

[barbas]

Should work OK if you don't need input 4 I2S. The FPGA jumpers are remapped to accommodate the new R7 front panel but there is a guide to remap the jumpers. Download "R2R7settingguide.htm" and "R2R7setting.jpg" to a local directory and open the HTML file. The .jpg should display in the HTML page...
https://onedrive.live.com/?id=636DC4E8060D66A1!313&cid=636DC4E8060D66A1

Thanks Scott. Yes, basically it should work as the Asy firmware I'm running right now.

 

[DACLadder]

Here’s a block diagram of the R7HE regenerative power supplies. First time I really given it hard look. On the left side the large transformer (50/60Hz) feeds the regenerator circuits that drive the DC linear supplies (right). Effectively AC-DC-AC-DC. The regenerative AC frequency is 50Hz which Kingwa says is better for audio.

http://www.audio-gd.com/HE/HE-7/HE DAC.JPG

 

[FredA]

Vince Galbo of MSB put out a white paper on AC Power some years ago describing the relationship between AC wire resistance and the power amp drawing instantaneous current in response to the music demands.
Essentially, the AC voltage waveform gets clipped upon transient current demand of the amp. Depending on the AC wire resistance and the amplifier power supply demands, the harmonics generated back to the AC line are modulated by the music signal which feeds your front end components and even being re ingested by the amp itself.
I have voltage regulated Krell mono blocks fed by 60' of 10 AWG at 240VAC. According to Galbo's wiring chart, this should have been sufficient.
On a whim, I ran separate 6AWG feeds and shortened the runs by about ten feet. The result was a much more relaxed presentation, clearer transients and soundstage.
Not sure if this even applies to headphone amps, but just sharing my experience with the power amp as a major source of corrupted power and its effect.... For what it's worth.

Running such long lengths, you sure need heavy-gauge cords. Interesting theory, i would have to read the white paper.

 

[FredA]

Here’s a block diagram of the R7HE regenerative power supplies. First time I really given it hard look. On the left side the large transformer (50/60Hz) feeds the regenerator circuits (AC-DC-AC). The three regenerated DC supplies (right) still use transformers but they operate at a higher frequency (400Hz). The large transformer also acts as a built-in isolation transformer.

From a basic level and concern to us audio geeks operating at 400Hz vs. 50/60Hz means less “rectification ripple”. The regen filter capacitors are refreshed faster resulting less droop between cycles. Less ripple = less DC noise to worry about. 400Hz saves weight also as caps, coils, transformers don’t needs to be as bulky as 50/60Hz parts.

http://www.audio-gd.com/HE/HE-7/HE DAC.JPG

What is power supply ripple? https://blog.powerandtest.com/blog/know-your-power-supply-jargon-ripple

I tought Kingwa used 400hz regeneration but this sentence taken from the r7-he's description seems to indicate otherwise:

400Hz regenerative wave have higher efficiency , 50Hz regenerative wave had much far away the human ears sensitivity area than the 400Hz, boost the sound have much better analog sound like.

 

[517269]

Running such long lengths, you sure need heavy-gauge cords. Interesting theory, i would have to read the white paper.

A key distinction from the paper is the misconception that because one may have dedicated 20A circuits running on 12AWG wire that they are good to go.
That the specification for steady-state current draw of 20A over a 12 AWG implies this is sufficient when it is not.
It comes down to the resistance of the circuit and via ohm's law, when transient current is being pulled by the amp, it will have a direct effect on the voltage waveform which is modulated by the transient nature of the music.

 

[DACLadder]

@FredA. You are correct. HE regenerates 50Hz. I will amend the above post!

 

[FredA]

2FredA. You are correct. HE regenerates 50Hz. I will amend the above post!

It is far from being clear to me how Kingwa's design works. He calling the second stage transformers the regeneration ones. What does the first transformer do?

 

[FredA]

From the schematics, it seems like the first part is producing dc to feed two gain stages (amplifiers) producing two opposed regenarated ac phase, while the three secondary transformers are being fed balanced power from that same source. Those transformer must be there of course to provide additional filtering and isolation between the 3 boards, besides adjusting the voltage to the needs of each of them.