HOLO Audio MAY DAC

[BrownMagic]

13 hours ago, barrows said:

Most well engineered DACs use this approach to produce their single ended outputs, and if the May has similar voltage at the balanced and single ended outputs, it is almost certainly using this approach.   

@GoldenOne Can you confirm if the May uses the same voltage for both Balanced and RCA? Many thank

[ted_b]

The May user manual clearly states the XLR are twice the voltage of the rca.

[barrows]

2 hours ago, BrownMagic said:

Would you be able to list a few that you are aware of that use this approach?

Any DACs which have similar output voltage form their single ended and balanced outputs.  Any DAC which has exactly half the output voltage from their single ended outputs vs the balanced outputs is almost certainly just using half of the balanced signal.  In my previous post i left out another common way to do balanced to single ended conversion which also results in high performance from the single ended outputs: using a transformer.  The transformer approach is used by Linn in the Klimax DSM, and by Lumin in the X1 DAC for two examples.

[Miska]

12 hours ago, barrows said:

Any DACs which have similar output voltage form their single ended and balanced outputs.  Any DAC which has exactly half the output voltage from their single ended outputs vs the balanced outputs is almost certainly just using half of the balanced signal.  In my previous post i left out another common way to do balanced to single ended conversion which also results in high performance from the single ended outputs: using a transformer.  The transformer approach is used by Linn in the Klimax DSM, and by Lumin in the X1 DAC for two examples.

 

I much prefer active conversion using differential amplifier stage. I usually combine this with cable capacitance compensated output buffer stage. This also avoids overshoot on square waves at preamp inputs and such, and allows both balanced and unbalanced connections to be used simultaneously and indepdently.

 

Transformers always add plenty of coloration.

 

[James Stephens]

Hi all,

 

In order to reduce vibration as much as possible, separate the power module and DAC module a little given that I only have one shelf for both (probably not necessary on the KTE give it has the copper DAC module covers), and to improve airflow I  made a Holo Audio sandwich utilizing 2x 1/2" thick acrylic sheets and a combination of IsoAcoustics Orea Indigo vibration isolators beneath the power module and IsoAcoustics Orea Bronze beneath the DAC module.

 

Yeah it's probably overkill ....

 

Best,

James

 

[MichaelHiFi]

11 minutes ago, James Stephens said:

Hi all,

 

In order to reduce vibration as much as possible, separate the power module and DAC module a little given that I only have one shelf for both (probably not necessary on the KTE give it has the copper DAC module covers), and to improve airflow I  made a Holo Audio sandwich utilizing 2x 1/2" thick acrylic sheets and a combination of IsoAcoustics Orea Indigo vibration isolators beneath the power module and IsoAcoustics Orea Bronze beneath the DAC module.

 

Yeah it's probably overkill ....

 

Best,

James

 

 

Maybe not overkill but what did you notice after the insertion of those devices? I know my Lindemann DAC streamer didn't at all like isolation feet. Sucked the life out of the music. Found that maple worked wonders though.

 

May sits on top of 3" maple but I haven't sat with my wife and performed an AB test yet. Too busy moving!

[James Stephens]

58 minutes ago, MichaelHiFi said:

 

Maybe not overkill but what did you notice after the insertion of those devices? I know my Lindemann DAC streamer didn't at all like isolation feet. Sucked the life out of the music. Found that maple worked wonders though.

 

May sits on top of 3" maple but I haven't sat with my wife and performed an AB test yet. Too busy moving!

 

Hi.

 

I configured this when I first installed the May KTE 2.5 weeks ago so I can't really say.

 

I am a big fan of the IsoAcoustics products. I have the Gaia Series Feet under my Speakers, Subwoofer and Amp stands and the Orea isolators under every component.

 

I have had such good results I didn't even give it a second thought when I put the May KTE in service ...

 

Best,

James

 

[BrownMagic]

On 5/26/2021 at 10:15 PM, GoldenOne said:

The may has full galvanic isolation on the USB input (full, not just 5v/gnd lines like some dacs) . Meaning there is actually no electrical connection between the USB and the dac itself.

The galvanic isolation is only for the USB or all digital inputs like Coax? Thanks much. 

[GoldenOne]

1 hour ago, BrownMagic said:

The galvanic isolation is only for the USB or all digital inputs like Coax? Thanks much. 

Just had a look inside, seems like it does indeed also have galvanic isolation on the AES/Coax/BNC inputs.
There is a Pulse electronics PE-65612NL isolation transformer just before the AKM SPDIF/AES receiver chip. So yep, seems it does!
I didn't realise that but it's certainly nice to know!

It's not 100% certain that this isn't just for the AES but not SPDIF etc, but if it's got this one (and everything else in the may that has been over-engineered as far as possible :P) then I can't imagine the other inputs would be left not isolated.

 

[k27R]

Does anyone know if the RCA outputs and XLR outputs be used simultaneously without degradation in quality?

[GoldenOne]

Just now, k27R said:

Does anyone know if the RCA outputs and XLR outputs be used simultaneously without degradation in quality?

They can be used simultaneously but I think you'll lose CMNR on the balanced because one 'half' will have an impedance mismatch to the other. 

 

This is the same with basically any balanced dac though unless it specifically has a separate output stage for SE

[Extreme_Boky]

3 hours ago, GoldenOne said:

They can be used simultaneously but I think you'll lose CMNR on the balanced because one 'half' will have an impedance mismatch to the other. 

 

This is the same with basically any balanced dac though unless it specifically has a separate output stage for SE

You can't "lose" CMRR... the amplifier section will benefit if the analogue signal is transmitted as balanced, from the balanced source (DAC), due to the capability of the differential input stage (located in the amp) to reject the common noise. In other words, the overall sound will have fewer distortions - especially 2nd harmonic... and further even harmonic distortions, as well as less noise), if the balanced transmission is used.

 

If only one half of the balanced signal is used, then that half is referenced to ground and it must have ground/shield connection as its return path - where balanced actually can work without the shield, but this is not recommended.

 

I believe that May have separate (isolated from each other) balanced and single-ended analogue stages. One of these days I'll have a look inside to be certain.

 

On this note, I prefer to use half of the balanced output as a single-ended output; this approach does not require an additional OP amp (or discrete transistor circuit that may require 4-5 transitions) for balanced-to-single ended conversion.  This is strictly when only one output (either balanced, or single-ended) is required at any one time.

[GoldenOne]

11 hours ago, Extreme_Boky said:

You can't "lose" CMRR... the amplifier section will benefit if the analogue signal is transmitted as balanced, from the balanced source (DAC), due to the capability of the differential input stage (located in the amp) to reject the common noise. In other words, the overall sound will have fewer distortions - especially 2nd harmonic... and further even harmonic distortions, as well as less noise), if the balanced transmission is used.

 

If only one half of the balanced signal is used, then that half is referenced to ground and it must have ground/shield connection as its return path - where balanced actually can work without the shield, but this is not recommended.

 

I believe that May have separate (isolated from each other) balanced and single-ended analogue stages. One of these days I'll have a look inside to be certain.

 

On this note, I prefer to use half of the balanced output as a single-ended output; this approach does not require an additional OP amp (or discrete transistor circuit that may require 4-5 transitions) for balanced-to-single ended conversion.  This is strictly when only one output (either balanced, or single-ended) is required at any one time.

I was meaning CMNR on the interconnect not the output stage. external influences could be a concern

[Extreme_Boky]

The noise gets cancelled due to capability of the differential input stage inside the amp to cancel (reject / not amplify) common noise. This include the interconnects' noise <- this is the whole point of having differential transmission; this is where the noise is induced. 

 

Differential interconnects hot and cold wires will exabit the same amount of noise: the same amplitude, and the same polarity, which will then be cancelled (actually, the right words to here use would be "would not be amplified") by the above-mentioned differential input pair. Only the audio signal (same amplitude on hot and cold, BUT opposite in polarity) gets amplified.

[MichaelHiFi]

On 5/25/2021 at 10:39 AM, Hiker said:

Well if you have ever experienced differences with switching signal cables in the past and or present please share ...

I'd barely know where to start but I'll say this. I've done countless cable comparison's. Countless. 

 

Last night I finally got a chance to make a USB comparison, but only locating 2 cables, a ~$250 dollar cable and a freebie still in plastic wrap. 

 

I gathered my wife and MJ 11 year old son, both have very keen ears. MJ's girlfriend listened too but didn't understand what we were doing. I didn't tell them what cable was being tested. But before they joined the test I listened first. I noted a difference between the 2 USB cables.

 

Note that my system is using a uRendu and an etherRegan, Supra Cat6, and Roon on a Small Green Computer (linux based).

 

My family (and MJ's girlfriend) joined me for the test. I played cable "A" using a song from Dido, very well recorded with a lot of content both in density and dynamic range. I played 3 minutes of the track then switched to cable "B". Very quickly MJ and my wife preferred cable "B". MJ stated that he though "B" was clearer and had more of a 3D sound. My wife thought that she could hear deeper into the mix, that instruments had more separation, was just clearer. MJ's girlfriend had no idea what we were talking about - she's 8. I was surprised and disbelieving. It was what I noted before the others joined the test. OK so now I removed cable "B" and returned cable "A". Cable "A" sounds great, barely perceptible to me that there's a downgrade in performance. But my family members again thought cable "B" sounded better. 

 

I rolled through a lot of music last night. There were some stinkers. Led Zeppelin remaster sounded almost harsh to my ears, others artists sounded awesome. Was it because I was hearing more of the truth of the recording? It was a song I've not played in perhaps years so further listening to familiar tracks is needed.

 

So what cable in my modest test sounded better? Understand that this test wasn't about USB cable vs USB cable, I don't have enough cables on hand nor do I have enough time to further evaluate and.. I'm no John Atkinson. This test was about wondering if there's a DIFFERENCE in USB cables in sound signature feeding my MAY KTE?

 

The free cable currently resides in our system.

 

 

 

[Quadman]

41 minutes ago, MichaelHiFi said:

The free cable currently resides in our system.

Does that free cable say Holo on it?  If so I was pretty impressed by that cable, best sounding free cable I've heard so far.

[BrownMagic]

On 5/25/2021 at 9:07 AM, GoldenOne said:

Personally I'd go either I2S if you have a good source like pi2aes

 

Will a standard I2S cable work between the May and Pi2AES? 
 

Also you mentioned about locking. If PLL is turned on, does it have to keep locking each time the song’s bit rate changes? 
 

Is there any scenario when turning off the PLL will be advantageous to SQ? 
 

Does PI2AES benefit from PLL being on?

 

Thanks much. 

[GoldenOne]

10 minutes ago, BrownMagic said:

Will a standard I2S cable work between the May and Pi2AES? 

Yes. Just set the May's I2S pinout to the "ALT1" layout and it matches pi2aes.
The configurable i2s pinout is a godsend

 

10 minutes ago, BrownMagic said:

Also you mentioned about locking. If PLL is turned on, does it have to keep locking each time the song’s bit rate changes?

It must lock every time the sample rate changes. Bit depth isn't an issue. But most music is gonna be 44.1khz anyway so you won't have an issue often.

 

11 minutes ago, BrownMagic said:

Is there any scenario when turning off the PLL will be advantageous to SQ? 

As I understand it the only time this would be beneficial is if the local clock is poorer than the source clock. But, given the incredible performance of the May's internal clock system, not just in terms of the clocks themselves but the actual implementation, this is VERY unlikely to happen. I've not found any digital source with outperforms the may's internal clocking thus far so It's best to leave the PLL on.

 

 

13 minutes ago, BrownMagic said:

Does PI2AES benefit from PLL being on?

Yes, there is a slight improvement in jitter performance with the PLL on. Though the pi2aes jitter performance with the PLL off is still exceptional.

 

[MichaelHiFi]

On 5/25/2021 at 10:39 AM, Hiker said:

Well if you have ever experienced differences with switching signal cables in the past and or present please share ...

 

2 hours ago, Quadman said:

Does that free cable say Holo on it?  If so I was pretty impressed by that cable, best sounding free cable I've heard so far.

 

Good question! I just grabbed a cable from my box of USB cables.

 

It says HP on it. Must have been for my newly acquired printer. Don't remember the May coming with a cable. Need to locate the box.

[TubeDriver]

On 5/29/2021 at 9:32 AM, James Stephens said:

Hi all,

 

In order to reduce vibration as much as possible, separate the power module and DAC module a little given that I only have one shelf for both (probably not necessary on the KTE give it has the copper DAC module covers), and to improve airflow I  made a Holo Audio sandwich utilizing 2x 1/2" thick acrylic sheets and a combination of IsoAcoustics Orea Indigo vibration isolators beneath the power module and IsoAcoustics Orea Bronze beneath the DAC module.

 

Yeah it's probably overkill ....

 

Best,

James

 

 

Makes sense to me.  I ended up getting new racks in order to have enough shelves to separate my KTE May from it's PS. 

[k27R]

What sonic improvements were you able to realize by separating the power supply instead of stacking?

[Heckyman]

I've had the May L2 (Wildism) for a couple of weeks now. Excellent sound quality with my Mac mini M1, nothing to add to what's already been said. Superb DAC!

 

Regarding set-up/installation, I first ran in the unit with the supplied USB cable. Substituting my normal Oyaide Continental 5S (£375) cable didn't reveal any obvious differences. Not motivated to investigate other USB cables.

 

Once I'd settled into the May's basic sound, I pulled out my Denafrips Hermes converter to test the other connections.

 

Considering some of the comments I've read on this thread, I was somewhat surprised to discover that the i2s connection (PLL ON) via the Hermes was slightly, but consistently, preferred compared to the USB direct. Just a touch more clarity across the board. The HDMI cable used was the 0.6m AudioQuest Pearl 48G (£31.50).

 

One slight niggle with this set up too. Despite sending 768KHz to the DDC over USB, my May is maxing out at 384 over i2s. Has anyone managed 768+ over i2s? 

 

 

 

 

 

[matthias]

8 hours ago, Heckyman said:

I've had the May L2 (Wildism) for a couple of weeks now. Excellent sound quality with my Mac mini M1, nothing to add to what's already been said. Superb DAC!

 

Thanks for sharing. 

I am just curious how May compares (from a musicality POV, not according to some audiophile terms) to the in-built DAC of the Mac Mini M1.

 

Matt

[Heckyman]

Interesting question, Matt!

To my ears both DACs are "neutral" with no niggles. The difference is just the extra resolution of the May. You can more easily appreciate the artistry of the musicians.

 

The other day, I was listening to Free with the family and we were all just blown away by the gravely tone of Paul Rodgers' voice. The discussion moved on to whether or not he is the best male rock vocalist EVER. At no point did anyone care to wonder if the hifi system had changed (they are only curious if I change speakers).

 

Another example, listening to Gregory Porter's 2nd album, "Be Good", I found myself captivated by the beautiful and subtle playing of the backing band. With the M1 DAC, you just have the general sense that there's a backing piano behind the vocal/lead. But with the May, you become aware of the tonality of each chord, its decay, the pianist's touch etc.

 

I could go on and on, but it boils down to simply not wanting to stop listening to music played through the May. In contrast, the M1 DAC requires more mental effort to reconstruct the musical content and is thus so much less engaging to listen to.

 

[matthias]

@Heckyman

 

Just an additional question:

 

Certainly you use the May in NOS mode and you might perform some additional upsampling in the Mac Mini M1.

If you do so which software do you use for upsampling and do you upsample to PCM or DSD?

Thanks

 

Matt