HOLO Audio MAY DAC

[mushi]

Hey guys, i've got problem with MAY... looks like i'm stuck... MAY jams while playing music. This happens when the audio signal is supplied via aes-ebu and coax connectors, it looks like this on the display: 96K / LOCKING / 96K / LOCKING / 96K / LOCKING .. music / silence / music / silence / music / silence .. If a track is three minutes long, 2:30s is the pause and 30s is the music that plays. This problem does not occur when i'm playing music via USB. To exclude the possibility of a fault on my part, i put the audio signal through the RME ADI-2 FS DAC (via aes-ebu and coax connectors) and the above problem did not occur: When i'm playing PC >usb> MAY there is no problem When i'm playing PC >usb> miniDSP SHD Studio > aes-ebu/coax> MAY jams all the time When i'm playing PC >usb> miniDSP SHD Studio > aes-ebu/coax> RME ADI-2 FS DAC there is no problem And now the best part: my source (PC) is not connected to the miniDSP SHD Studio, i'm connecting miniDSP with the aes-ebu/coax connector to MAY and MAY starts locking... The seller claims that it is miniDSP fault, that miniDSP generates a signal that causes HoloAudio locking: "...May is very precise with its locking mechanism. Some sources do not sent clock signals all the time (while music is paused e.g.) and you will see "Locking" on your display when there is no signal output from the source."   So my setup look like this: Roon >usb> miniDSP SHD Studio >aes-ebu> MAY >... I'm using miniDSP SHD Studio as a preamp, also i can set the gain on the output:   I tried different settings but it didn't change anything..

Please tell me what do you think because i have already gone stupid...

[mushi]

I hear you bro, you might be right about miniDSP, my knowledge of clocking is almost none so i'm investigating miniDSP now. A moment ago i wrote to their support and we'll see what they answer. miniDSP has ADSP-21489 processor inside, but if it is responsible for the clocking and how does it relate to MAY, i don't know. Maybe in the worst case scenario something like Mutec MC-3+ Smart Clock would help, what do you think?

 

As for cables i use Mogami:

- Reference Digital 3173 AES/EBU 110Ω DMX

- S/PDIF 2964 RCA Digital 75Ω

[mogami claim that lifetime warranty;]

 

I can still try to borrow some other source with aes-ebu output and we'll see what happens then.

 

9 hours ago, GoldenOne said:

Maybe switch to using roon volume control and don't use the minidsp. That way you can use USB instead. Plus roon has incredibly powerful and easier to Configure dsp options anyway

 

Noooo, i'm afraid it's impossible because my new children arrived yesterday

 

I think that dsp from Roon can't handle setup with two subwoofers (crossover, filters, phase correction), mini is a tank in my setup: dsp, preamp and roon endpoint.

[mushi]

Almost forgot: thanks for the help @GoldenOne ;)

 

I'll let you know when miniDSP support team writes back.

[mushi]

Yup, turning off PLL works perfectly.

Apparently this problem happen when a source spdif signal is out of standard clock tolerance(+-50ppm)

 

I'm curious what the miniDSP clocking looks like, and i wonder if it can be improved somehow?..

 

 

[mushi]

5 hours ago, barrows said:

This confirms that the mini DSP has too much jitter.  When you turn off the PLL of the May, then all the jitter from the mini DSP goes right on through to the output of the DAC, and you are not getting the sound quality that you paid for.  Time to ditch the mini DSP if you want to achieve the sound quality which the May DAC is capable of. 

"when a source spdif signal is out of standard clock tolerance(+-50ppm)" this is what my seller says. He also says that his HoloAudio MAY connected to Panasonic TV (through Toslink! which has worse jitter than aes-ebu) works flawless.

 

Panasonic TV is not a Pro Audio Device. miniDSP is. So it's reasonable to assume that my HoloAudio may be broken.

 

Of course there is a chance that miniDSP may have a very serious deffect, but we don't know this yet. We can bet. Chances are 50/50. It must be either a gigantic error generated by miniDSP or the HoloAudio PLL circuit is defective.

 

4 hours ago, juanitox said:

or time to use the inside dac of the MiniDSP SHD wich seems very good,  https://www.audio “science” review/forum/index.php?threads/review-and-measurements-of-minidsp-shd-dac-dsp-and-streamer.4286/

sometimes simpler is better aand you will save a lot of money..

Bro, it would save me a lot of money, time and nerves.. but i've got SHD Studio, without DAC..

 

 

[mushi]

No Goldie, there is no toslink (MSI GS65).
I call dealers now, looking for good one who will agree to lend me a source with digital spdif output.

[mushi]

On 10/16/2020 at 4:37 AM, Diavolo said:

I had locking and intermittent audio drop out with my nvidia shield sending audio through my Samsung HDTV via Toslink.  I simply enable PCM Oversampling on the May when I watch things on the Shield.

Damn it, just now I checked that the SPDIF locking only occurs in NOS mode!!!

PLL on OS/OS PCM/OS DSD mode works fine.

 

Can anyone explain it to me technically? My support from MagnaHiFi can only copy/paste information from the KitsuneHiFi home page..

[mushi]

UPDATE

 

I think we have found first scratch on HoloAudio marvelous reputation.

 

On 10/8/2020 at 11:28 PM, GoldenOne said:

@mushido you have a pc with optical output you can try? If that does not work with pll then you know its the dac.

 

If it does, you know it's the minidsp

 

I just bought a digital tuner and connected it to May through SPDIF Coax, and guess what? It's LOCKING!!!

It looks like there is malfunction PLL and NOS mode with SPDIF signal (OS/OS PCM/OS DSD mode works fine).

 

On 10/8/2020 at 4:36 PM, barrows said:

This confirms that the mini DSP has too much jitter.  When you turn off the PLL of the May, then all the jitter from the mini DSP goes right on through to the output of the DAC, and you are not getting the sound quality that you paid for.  Time to ditch the mini DSP if you want to achieve the sound quality which the May DAC is capable of. 

 

Through this time I contacted with miniDSP support team, and guys took this problem seriously:

- miniDSP engineers put the SHD Studio on the APX555x to check the locking and metadata and everything seems fine. The metadata for SPDIF/AES-EBU is indeed correct.

- FYI, their device always outputs the clock actually. No matter if muted/paused, it's always outputting the clocking+metadata.

 

And now best thing:

- when miniDSP engineers are asking for more details on the metadata which HoloAudio expect, and are asking about more details of HoloAudio clocking circuit (the one that shows an unlock), MagnaHiFi doesn't know the answer or copy/paste marketing blurp about PLL circuit from KitsuneHiFi homepage, but Tom from KitsuneHiFi gave me better answer: turn off PLL. Thats all.

 

HoloAudio claim (from KitsuneHiFi homepage) that:

"A common technique to improve the clock signal from SPDIF is PLL."

and

"Now the May is implemented with femto clocks, and also new discrete ultra high performance voltage regulators. It has an advanced PLL (phase lock loop) circuit that is completely custom built for ultra high performance anti jitter performance. Even the highest levels of jitter are near eliminated which delivers world class performance."

 

Why should I turn off the PLL? In order to degrade the sound quality?

What is the PLL installed there for? Just for looks?  Such a marketing trick to make more audiophiles buy this device?

 

And my problem is that I am not able to convince myself of it's spectacular performance because it does not work..

 

 

What do you think guys?

 

 

 

[mushi]

4 minutes ago, barrows said:

A PLL has a kind if window function, and the opening of that window can be wide, or it can be narrow.  A very wide window will be able to lock to high jitter streams coming in, and a very narrow window will require a lower jitter signal to begin with.  For example, the ESS 9038 DAC chip has an onboard PLL, with an adjustable input "window", when you adjust the window to its lowest opening, the DAC will not lock to some (higher jitter) sources, and the solution is to either open the window a bit, or reduce the jitter of the source.  Opening the window a little wider is a compromise, because it will let more of the source jitter through.  The best solution is to reduce the source jitter.

Sounds like the Holo Audio May has a fairly narrow window in its PLL circuit, so one may need to deactivate the PLL for some high jitter sources-If this is what is happening, then one cannot blame Holo Audio because their source has too much jitter, the source is the problem, and Holo audio can accommodate that source by turning off the PLL.

 

Alternatively, it is possible your specific May has a problem with its PLL circuit, but I have not heard any evidence which suggests strongly thta is the case here, still could be though...

I hear you.

But how do you explain that miniDSP and PLL works together on OS mode but on NOS mode doesn't?

And I'm not the first one, @Diavolo has the same problem with SPDIF.

 

[mushi]

17 minutes ago, GoldenOne said:

When you say minidsp put it on the apx555 did they out YOUR one on it? Or just one they had? It's entirely possible that it's just your unit and not the product design itself. A faulty oscillator maybe. 

No, it was one of their devices.

 

miniDSP SPDIF/AES-EBU clock is generated by the SHARC ADSP-21489 + SPDIF/AES-EBU Digital transmitter by AKM. Thats all I know.

 

 

17 minutes ago, barrows said:

Without knowing more about the exact circuitry of the DAC i could not say, this is a question I would suggest you address to Holo Audio.

I did it, and Tim from KitsuneHiFi put me off: turn off PLL, that was all his answer.

 

EDIT:

Thanks for your effort to help guys.

[mushi]

 

1 hour ago, barrows said:

Sounds like the Holo Audio May has a fairly narrow window in its PLL circuit, so one may need to deactivate the PLL for some high jitter sources-If this is what is happening, then one cannot blame Holo Audio because their source has too much jitter, the source is the problem, and Holo audio can accommodate that source by turning off the PLL.

 

What you are saying is in opposite to what is HoloAudio claiming:

 

 

 

 

[mushi]

Hey guys, tell me honestly, can you hear the difference between on and off PLL?

USB / SPDIF / whatever?

What your golden ears say?

[mushi]

Hey guys, for the past few months something has started to happen with my holo may: the power section is clearly heard after switching on, as is the noisy transformer through which the current flows. I'm not sure, but it seems to me that the holo was quite quiet at the beginning, it was only in the last couple of months that i started noting this issue.

 

In the evening, after connecting holo to the power, i can hear from the listening position (2.5 m) how the power section works. And only once so far, it happened that for half a minute the holo power section started to rattle really loud and then calmed down, it bothered me...

 

Are your holos silent?

 

[mushi]

Wow! Thanks guys, i'll definitely try one of those.

 

At this moment i can try ifi dc blocker. Also found that emotiva cmx-2 works for some people, but i need eu plugs.

 

[mushi]

On 10/5/2021 at 2:00 AM, firedog said:

https://avahifi.com/products/humdinger-dc-line-blocker

 

I can testify that this works.

Please tell me, did your holo make noise from day one or did it start making noise after a while?

[mushi]

1 hour ago, Extreme_Boky said:

My May toroids started making noise after a while. It is not the DC on mains. It is a constant current draw of the output stage working in class A that's causing it - causing the flat wire windings to become slightly loose and start to hum. The toroid is made by order... if you check the plastic wrapping used - you'll see that is not ideal, it is too stiff  😲 - it does not keep that flat copper wire under sufficient tension to prevent vibrations. 

 

Here's how you can determine if it's DC on your mains supply, or the high quiescent current of the output stage (and that plastic wrapping...) that's causing the hum/buzz:

 

- bring your ear very close to the power supply unit

 

- turn the power ON (on the May DAC unit). You'll hear the relay inside the power supply box click (the first click). This will apply the mains (110/120V AC) to the toroids' primary. At this point, if you hear the buzz straight away (straight after the first click) - it's the DC on your mains

 

- If you still can't hear the buzz, wait for 2-3 seconds until the relay inside the May DAC unit clicks (the second click) - which will apply the voltage to the output class-A stage (and the high quiescent current will start running through the output stage). If you hear the buzz at this particular point (after the second click) onwards, it's the loose windings... stiff plastic used for windings' isolation/wrapping.

 

 

This is very interesting!

 

After turning on the voltage on the back of the May power section, you can hear the current flow very quietly.

 

Then, when you turn on the power button on the resistor section, May's power section immediately starts humming, and after second click after three seconds, it hums at the same level.

 

That earlier episode with a half-minute loud intense rattling scared me into thinking May was about to explode or burn up..

 

If this humming effect did not occur in the beginning, is it possible that some capacitors have worn out partially or the power converter?

 

Yesterday I took a closer look at it:

 

 

I checked organoleptically up close and marked with red circles where the noise level is highest. What surprised me was that when I put my ear to the transformer from above, I could hear almost nothing. From the top you can hear the hum the most in the area of the left blue element and capacitors (with the right blue element also, but a bit less) and in the area of the transformer, but from the bottom next to the housing, strange, maybe vibrations go to the housing there, I don't know, but you can't hear it from above so as from the bottom in the mounting area with the housing.

 

It was hard for me to say unequivocally that there is a hum in EXACTLY THIS PLACE.

 

[mushi]

45 minutes ago, Extreme_Boky said:

 

From what you wrote above, it seem like you have DC on mains. So, get the DC line blocker. 

 

 

I wrote to the seller in this topic, we'll see what they answer, I guess the same.

 

I would like to stuff something like this in May, but I'm afraid the capacitors will be too high.

Or insert this blocker into a larger power strip.

[mushi]

I'm sure that i'll try this device soon.

 

Thank you guys for your time,

m.

[mushi]

On 10/10/2021 at 2:30 PM, Extreme_Boky said:

 

From what you wrote above, it seem like you have DC on mains. So, get the DC line blocker.

 

I used a dc blocker yesterday and unfortunately nothing has changed. I wonder what's next..

[mushi]

On 10/30/2021 at 8:59 PM, Extreme_Boky said:

I suppose going back to your distributor would be the next step.

 

Probably.

 

Maybe sooner i will take may to someone to check if the same is happening in another apartment.

 

On 10/30/2021 at 9:01 PM, GoldenOne said:

Out of curiosity was it the ifi one? 

Have seen a couple people saying that the ifi dc blocker only reduced their dc offset but didn't fix it. 

 

No, i'm waiting for the distributor to get the ifi.

 

On 10/30/2021 at 9:06 PM, Extreme_Boky said:

The best would be to measure the amount of DC on mains. Then, the appropriate DC blocker can be either ordered, or DIY-ed so that the full amount of DC is removed. 

 

Measuring dc on mains is probably not that simple (do i need an oscilloscope or other specialized device for this?)

 

For may a bespoke dc blocker was diy-ed:

 

 

 

It is calculated to handle max. current of up to 4,5A and the max. dc blocking voltage of approx. 2V

 

I have no idea why it doesn't work.

 

But my blood is boiling when i think that i will have to contact the seller again, he will probably write back after checking may that Dutch current after greasy joint is calm and does not bother him.

 

 

 

 

After turning on the power section on the back, you can hear the current flow in the marked place. And when the r2r section is turned on, the transformers speak through the housing. Maybe something is broken on this route.