HOLO Audio MAY DAC

[darioG]

Hi , new to this forum, first post so please  be gentle, I know I'm not worthy! 😉

I am a bit of a Noob and don't understand some of the technical speak on here to explain shortfalls of Pi2aes setting with I2s. on Holo May L2, vs Usb...

 

I recently purchased the Holo May L2 dac after watching GoldenOne review.  I am current feeding signal through my Allo Usbbridge Sig with Shanti power supply (Ropieeee as Roon endpoint.). 

I coupled the Allo Usb to Holy May with a Curious Evolved usb cable.  This sound really natural to my ears:), but found that roon upscaling made sound too digital to my taste.  Hqplayer filters may help, will try when new hdmi cable arrives and will compare i2s and usb.

 

I though I would experiment 🙂

 

 I have also purchased a Pi2aes which I can also power with the Shanti power 5v power supply direct to the Pi2aes hat. 5v pins 

I had a £40 4k 1m hdmi cable which just tested to see if connection works! I found that I2s input kept locking between 5 and 15 seconds!!  I assume it was my hdmi cable. because it happens between albums and tracks, not just when turn on Holo dac.

 

I have just purchased a RAL .75m Prophecy CryoSilver™ Reference HDMI cable, should arrive soon.  

Hoping this will fix the locking but it may also be I2s port pinout setting on the Holo may dac???

 

Will polarity be effected and left and right channels be reversed when connecting pi2aes to Holo May I2s?  

 

Could someone please share the correct I2s Port pinout setting within Holo May dac setup to connect Pi2aes to holo may dac i2s?

Regards Darren

Hegal H390 amp, XLR to Holo May L2 dac, Allo usb bridge sig roon enpoint. Pi2aes, I2s, Roon endpoint, Shanti 5v power supply.  Dali Epicon 6 speakers.

[darioG]

8 hours ago, John Hughes said:

It's in the manual (attached).  The May uses the same pinout as the Denafrips and PS Audio.  The delay you are experiencing is common with the i2s, its the PLL Lock.  If you disable the PLL Lock the delay will clear up.  If you have an HDMI cable thats about 1/2 meter or so, changing cables probably won't address that.

 

I've also used the USBridge Signature with Shanti. Its good. I'm using the Stack Audio Link II  with LPS now which runs a custom version of Ropieee. I definitely prefer that. 

 

I use USB from the May to the Link II directly for Roon. 

 

I use an Nvidia Shield as my second source for video.  I have tried 3 different USB to i2s converters so I don't have to switch USB cables for sources.  A cheap one from Ebay, the LKS USB-100, and the Kitsune Edition Singxer U2.  The cheap no name did work, but the audio was not that great.  The LKS made a nice upgrade, and is fairly inexpensive.  The Kitsune SIngxer U2 is definitely the best of the three.  I tried the Link II connected to the U2 and I would say it was too close to call vs direct USB connection to the May.  And the PLL Locking issues were worse adding in any of the DDCs.  So I'm not using it that way.  

May-Manual-English-V1.2.pdf 850.06 kB · 7 downloads

Thank you John for your reply. :)

 

Is the SQ of Stack Audio worth the extra £700 with LPS compared to the Allo USB sig, Shanti?, I am only going to use as Roon endpoint, so other features are wasted on Stack Audio!. If not a lot of SQ difference, I will stick with Allo. Unless find Stack and LPS second hand :)

 

If I turn off PLL lock I2s , will the effect be jitter?  Is the PLL just buggy with I2s, don't have issue with usb PLL locking...

 

I like the SQ of Roon compared to other software , Audirvana SQ didn't do it for me at all, plus all the bugs!

 I have seen the pinouts diagram and the different options in the manual, but when look on diagrams to compare with PS audio or denafrips pinout nothing like diagrams in Holo manual..(Alt1-Alt2 Or Alt3?) Anyone confirm which should select?  or is just connect hdmi cable select one which you get sound output and the stereo channels output from Holo XLR ports will be the correct way round ect?

 

[darioG]

19 minutes ago, barrows said:

The PLL is not buggy.  A really good PLL will take a long time to lock depending on how much jitter is present in the source, sometimes, if the source has too much jitter, a good PLL may not be able to achieve lock at all.  The long time to achieve lock indicates that your source has somewhat high jitter, and that if you turn off the PLL that jitter will get into the conversion stage, and produce artifacts in your analog output.  For best sound, keep the PLL on to reduce the incoming jitter, and live with the wait, or, even better, get a better source with less jitter in the first place.

Also, it is good to remember, that even a very good PLL does not eliminate incoming jitter, it actually just turns short term jitter (which is generally what produces objectionable sound quality) into long term jitter (which is generally inaudible).  It is always going to be a better fundamental choice to reduce the source jitter as much as possible.

According to Goldenone measurements between the PI2AES and Denaphips ddc, the PI2AES has lower jitter from I2S than the Denaphips ddc 🤔   

[darioG]

On 3/12/2021 at 1:11 AM, GoldenOne said:

TLDR: 
- May's PLL is incredible, and even optical from my PC outperforms dedicated DDCs by orders of magnitude with it enabled.
- May's internal USB is also absolutely fantastic
- Pi2AES is crazy good for the money, and outperforms the Denafrips Hermes DDC (I imagine having no USB in the chain anywhere is a benefit)

Ok, so I did some measurements of inferred jitter from a few devices using the may. May's own USB/internal DDC (this is the upgraded L2/L3 version), denafrips hermes, pi2aes.

(USB source for all devices was sotm SMS200 Ultra. ADC running on Raspberry pi 4 to avoid any potential windows USB problems)

Lets start with 44.1khz
- Pi2AES wins hands down here. With sidebands (deterministic jitter) only going up to -135dB, vs about -125dB on the hermes.
- Hermes additionally has a considerable amount more random jitter (shown by the 'shelf' which reaches up to -137dB, whereas pi2aes never goes above about -144)


 

Moving to 48khz
- Here its much closer, though pi2aes pulls ahead still. Both devices have deterministic jitter of about -143dB, however the pi2aes' sidebands are constrained much closer to the fundamental, whereas the Hermes has additional sidebands further out.
- I added pi2aes coax for a quick comparison here too. We get slightly poorer inferred jitter via coax than we do with i2s. With small sidebands below -136dB. I2S is definitely the better choice if your DAC supports it.

 

What happens if we turn on the PLL?
- Effectively, any jitter that I can possibly measure gets eradicated. With the may's PLL on, both sources show all jitter down at -150dB and the limiting factor immediately becomes my ADC's own accuracy. With the PLL on, its likely that actual jitter is lower than what is displayed here, but I'd need a state of the art analyzer + notch in order to measure it.
- I even tried the worst source I had (Optical from my PC), which was plagued with jitter, and the PLL just absolutely eradicated it.
- I tested may's USB implementation as well, and we can see that it's pretty excellent, with no clear deterministic jitter, and keeping all random jitter below -140dB. The USB performance did not change when the PLL was turned on or off. This means that May's internal DDC could potentially be considered better than pi2aes/hermes given as without PLL it gets better performance than either of them. However given as with PLL enabled, I2S interfaces beat it, pi2aes, i2s, PLL ON delivers the absolute best performance you could possibly ask for or measure.

I have a Shanti powering the PI2AES and when use I2S to May L2 takes ages to lock and then when it does, doesn't always stay locked? If the PI2AES has not got as much jitter as denafrips dds, why is the May not locking as fast as when May is connect to my ollo USB sig and Shanti? 

[darioG]

8 minutes ago, GoldenOne said:

Are you definitely using the correct I2S pinout?

Sounds like there is an issue with the connection, or your PSU is not providing enough power to the pi2aes. What voltage and current rating is the PSU?

For Pi2AES the I2S input on may should be set to "ALT1" layout

 

I was using the Alt1 setting.😁 Thanks for confirming setting with pi2aes. The Shanti is 5v 3amp. https://www.audiophonics.fr/en/hifi-power-supply/allo-shanti-dual-regulated-linear-power-supply-5v-3a-5v-1a-p-14009.html. Only using 5v 3amp to 5v pins on pi2aes hat with ropieee basic as roon endpoint. I mentioned in another post that might me the £40 4k hdmi cable 1m in length I have . Waiting for a new silver core. 75cm Revelation Audio Labs hdmi cable, hopedully that will help🤔 

[darioG]

On 6/28/2021 at 11:22 PM, John Hughes said:

So, I started with a standard Rasperry Pi 4 using the Standard Allo recommended firmware (is that called Diet OS?  I can't quite recall).  This was before I was using the May.  Then I got the Allo USBridge Signature with Shanti LPS.  I could definitely hear the difference.  Less noise, wider soundstage, cleaner treble, deeper bass.  I got the May while I was using this setup.  I used Ropieee, as I was having issues with the Diet Os. 

 

Then I got the Stack II (the LPS was a month slower in shipping at that time).  Without the LPS, it was significantly better in the ways I value:  much cleaner, with more open midrange and treble, lower noise floor, just a lot less digital grunge in the sound.   When I got the LPS I was kind of surprised in that the difference was even more than adding in the Link II.  Much deeper soundstage, inky black backgrounds, and BASS.  The bass filled out a lot on the bottom with more texture and a bit more on the low end.  Very clean sound overall too.  Plus the Stack software is very nice, the custom Ropieee implementation update automatically, and I haven't had a problem with it.  It has HQP software installed as an option in the interface as well.  I will also say that the Stack II and the power supply have beautiful, solid, heavy housings, they are much nicer to look at and beautifully engineered.

 

As to jitter without PLL, its really about audible differences, isn't it?  Some here say they've heard a difference with it off.  Tim at Kitsune doesn't believe the difference is audible. I can hear a very small difference in sound without it.  But the difference is very small to me, maybe 1/5 of what you hear between USB cables etc.  So I've accepted using it without.  Sometimes I will run a little listening test with in on and off and I continue to think its too small to matter vs the PLL locking issue.  I will say that I am particularly sensitive to digital noise and hear differences in all aspects of cables, isolation, power filtration, but this particular difference is not significant to me. 

 

I suspect that how bad this kind of jitter affects a DAC may have a lot to do with how clean the source is.  If you are going direct from a PC etc it might be more audible than my setup which has major power filtration. fiber optic ethernet isolation and using an endpoint designed to be low noise. 

Hi

 

I went and ordered the Stack Audio 11 plus & LPS. They offer a 30 day money back returns policy on product. I did see on review Han did of the stack 1 Stack Audio Link streamer and network bridge - YouTube Hans reported that the upgraded LPS didn't make a difference to the sound.  I will compare for myself and let you know if I hear any difference on Stack 11.  I will keep hold of the Allo usb sig for now,  judging the differences you heard, I don't think will be going back.  Thank you for the info.  Daz