Holo Audio Red and A-link compatibility
Hello!
I have new streamer called Holo Audio Red.
Really fitting device to my Audial S5 rig. It's pure minimalistic design with one LED 🙂 - even configuration is very simple.
Currently using ALT2 configuration (which I believe corresponds to the PS Audio standard) over I2S.
I want to ask if other option are possibly compatible with "A-Link" mode? the description in S5 manual is bit different than Red streamer manual.
Page from manual below:
Thanks for reporting this.
Yes, it looks like ALT2 matches the PS Audio I2S standard.
ALT1 and ALT3 should fit the A-link I2S pinout for + signals, so the channels are not reversed, and the absolute phase is correct.
Terms LRCK (Left/Right Clock), which became more widespread, and WS (Word Select), used in the original Philips I2S specifications, are "synonymous", they denote the same signal.
Just tested. S5 switched to "SIM".
Result is the same on both ALT1 and ALT3 there is only sound in left channel and it's extremely distorted.
It should be set to I2S.
As I understood, it worked with Red set to ALT2?
So SIM switch position is used for connecting two S5/S5b for 4 channel operation?
Tested again on i2s mode and results are:
ALT1 = swapped channels.
ALT2 = using that on daily basis, working great.
ALT3 = Working properly.
So which is more aligned with your standard?
Btw. tested additionally upsampling and for ALT2 + ALT3 the highest possible value is 96kHz.
Practically speaking: mostly yes. The mode switch should be actually set to SIM to work with any source that outputs Philips simultaneous data protocol (and matches specified pinout and voltages), but it narrows down to the S5/S5b and AYA 5 devices (so two devices can operate as 4-channel USB DAC), and Audial USB Mk3 interface board, which was released only once, as a limited edition.
Regarding the Red configuration, I would expect the channels set properly in modes ALT1 and ALT3, because the LRCK signal at pin 7 is then positive, which fits A-link WS requirements.
ALT2 sets the negative LRCK signal to pin 7, which, when you connect it to A-link input, swaps the channels.
Also, ALT1 and ALT3 set the positive DATA signal to pin 1, as required by A-link specs.
ALT2 sets the negative DATA signal at pin 1, which, when you connect it to the A-link input, produces the inverted absolute phase (polarity) at the audio output.
So, I would expect ALT1 and ALT3 to operate properly with A-link input, set to I2S mode. It looks like the modes ALT1 and ALT3 are the same for PCM (I2S) output, and differ only in their DSD specs.
Yes, the highest expected FS for S5/S5b A-link input operating in I2S mode is 96 kHz.
I just took possession of a used Holo Red I purchased on Canuck Audio Mart from a reputable seller. I’m having difficulty deciphering how exactly to setup and connect using i2S. Roon nucleus server - Holo red to the S5b. USB works just fine once configured. I2S I only get one channel and the other is weak and distorted. Adjusting dip switches as instructed above and saving in the Holo Red setup webpage does nothing. Results are the same. I have not tried the A-link input. Any help in sorting this would be appreciated. As I’m sure you’ve already gathered, I’m not a particularly technical person either, which doesn’t help. Thanks in advance!
andy
Hello Andy,
This might be the issue detected in the first S5b series, as documented in the S5b changelog (August 2024).
You can probably verify this by power cycling the S5b while leaving the source in playback mode. If this solves the problem and makes both channels work normally, it would confirm my assumption.
If I am right, we are, of course, due to fix this bug, at our cost. We can proceed and check the details via email.
Pedja
You are indeed right. Power cycling solves it and makes both channels work normally. However, when the next track cued to play - which was also FLAC 44/16 - a very noticeable 'pop' out of the right channel and the same problem resurfaced, with static on right channel while left plays back fine. The power cycle once again corrected it. This time 3 tracks played fine before it happened again, so it's somewhat inconsistent. Sounds great when working well, arguably slightly better than usb, so it would absolutely be great to get this sorted.
Andy
Hi Pedja,
Quick good news update. I've set the Red to Alt 3 and am using the A-Link connection set to i2s. It's working beautifully. And very happy to report no pops between formats (which I did experience via usb and i2s, and also via usb from Roon Nucleus), so this is excellent news. It sounds terrific.
Andy