HOLO Audio MAY DAC

[Quadman]

14 hours ago, Extreme_Boky said:

The capacitors we are talking about (you replaced) are used to de-couple the power supply rails (I think they are analogue power supply rails

Tim said they had something to do with the power supply and I believe you are correct that they are analog.  I sure love the Auricap so far which may push me to not roll capacitors.  Getting to the undersides of the boards to solder is a lot of part removal, not difficult but tedious and one has to keep their wits about themselves.

 

For the 2 switches on the PCB (voltage selector) I would probably want a re-work station to safely remove.  I used an old solder removal iron with a bulb to suckup solder for the cap and connector removal.  Those solder pads are a bit larger for this switch.  Should be worth doing tho.

9 hours ago, Toni-Mang said:

I am not sure, how much added value i get from the cabling (and material) in front of the transformers, which are still plugged in and out. On the other hand, the vishay caps

The AC cabling I added probably does not add much and due to the work involved I decided not to remove those quick connectors the O type transformers use to connect to the PCB.  I do think what @Extreme_Boky said about getting the switches out of the signal path does have real merit and would definitely be audible and probably take my dac above the KTE level now.  Of course then your dac is stuck, for resale, in a same voltage country as you are currently in.

[Quadman]

40 minutes ago, Miska said:

Yes, you need to consider difference between digital levels and analog levels...

Thanks Jussi, I realized after I wrote it that its the May that lowers DSD 6 dB, in the PC and HQP there is no DSD output penalty.

[Quadman]

2 minutes ago, Miska said:

So the level difference is just 3 dB at maximum possible peak level.

ah that would explain why I ended up with my HQP min vol at -4 as I used to very occasionally see limiting when it was -3.  Until the Holo, 100% of my streaming was DSD512 via T+A.

[Quadman]

22 minutes ago, dkdali said:

And good to know it’s normal though quite surprising for a dac!

Per stereophile:

 The May uses an op-amp input stage and a discrete, class-A transistor output stage.  The converter chassis runs class-A warm-to-the-touch.

 

So do not stack components on top of the dac chassis.  Mine runs about 98 degree Fahrenheit.

 

Although I didn't look at every cap the ones I spotted easily are 105 C

[Quadman]

Here's your heat source.  4 Transistors biased into class A.  Facing down near back of dac, but heat rises.

[Quadman]

1 hour ago, sledwards said:

Any chance that the bottom cover has some sort of thermal interface material located over the top of those 4 transistors, with the intent being to have a thermal conduction path to the bottom cover?

I didn't see any thermal interface on the bottom plate.  My dac, not PSU, sits on my now unused phono stage, with nothing on top of it but 3 brass weights with felt base for extra damping of top plate.  It runs just warm to the touch and my IR thermometer show 98 degrees F.  That is not hot.  We'll have to see after @dkdali removes the Innuos from the top of his dac if it still runs hot.  If it has good open air around it it should just be warm, if not then something is wrong inside the dac, and I would unplug and notify Tim

[Quadman]

2 minutes ago, dkdali said:

I will be looking in to getting a rack as my 5 stack + amp

You still have a lot of stuff on the dac.  Is it just warm to the touch now so you can leave your hand there?

[Quadman]

59 minutes ago, Extreme_Boky said:

 what the heck are those cut-outs in the PCB?? 

 

They sure do look odd in the photo and I don't remember them looking that odd in person.  Below picture shows what I think are the items that you point out with your arrows.

 

Using your arrows as guides the right arrow has to be this omron 2 pole relay switch.  The middle arrow is probably that bank of 4 small caps and the Left arrow is that tiny device under the USB board, I can't read it to make out what it is.  Kitsune site has some decent shots of it.  So this is flux residue combined with solder and shadow reflections making it look very odd.

[Quadman]

Just now, Extreme_Boky said:

but they did look strange to me...

Yes they were a bit sloppy in cleaning off flux residue, not sure what type they used but it must not hurt PCB's.  Throws a crazy shadow tho.

[Quadman]

9 hours ago, Toni-Mang said:

left over flux on the MAY Board is very irritating indeed…is this factory style?

Yes, I only replaced 2 caps, you can see what I did in the darker circle areas.  The rest is factory, but the Picture makes it look way worse than it actually is with light and shadows playing together and doing crazy things.  To the naked eye it was nothing alarming.  Hand soldered I am sure.

 

So if @Toni-Mang can stack like this and have no heat issues and @dkdali had major heat issues maybe something is wrong with his dac, maybe the internal voltage switch is set wrong, or 2 pads on the Dac module are shorting or a bad component.  I'd email Tim for his perspective.

[Quadman]

I bought my dac used so did not have to go through the break in period but I find it hard to believe this Dac could ever sound bad.  The music it is making in my room is SOTA.  Thursday I completed my AC line upgrade in which I removed all switches from the AC line.  The on/off switch on the back is now bypassed (fuse is still in circuit), and the two voltage selector switches (110 or 220) on the PSU PCB are now bypassed.  Skeptics will doubt this, but this change made a very nice uptick to the sound quality.  I put it only slightly behind the Capacitor upgrade I made on my previously L2 dac.  KTE owners may want to consider doing this mod as you will be very pleasantly surprised by the SQ improvement.  So I now have a dac that has a feature the KTE's do not AC switch bypass.  All I am missing is EMI/RFI cover for R2R boards and I'm working on that.

 

What first caught my ear and full attention after the mod was percussion and the utter transparency of it, with full body and presence.  It was very good before but this was another level.  Percussion to the sides be it finger snaps, stick hitting wood etc it was just more there.  Lead center imagine weather vocal or instrumentalist also gained in transparency, weight and presence.  Overall the music was more involving and engaging, back to what Herb Reichert said "The May recovers the natural pressure behind the musical flow" but now add to that greater transparency, presence and body.  Mesmerizing, my listening sessions regularly run 7+ hours now, zero fatigue and great reluctance to turn the system off despite the very late mourning hours (3-4am).  Music has never been this engaging in my room and that includes my SME 30 TT with dynavector XVs1 cartridge.  I listen at DSD512, PCM 1.5 while dynamic and transparent (not sure it is more transparent than 512) is 2D and thin, and lacks soul.  DSD256 EC7 shrinks this marvelous (512) soundstage, it's like you vacuum packed the 512 stage and now DSD256 EC7)  My CPU with no cuda struggles with 1024 DSD but what little I hear, oh my.  12th gen intel, can't wait. I use a i7-10700K CPU

 

on/off bypass, remove jumpers connect L to top of fuse, N to top of IEC

 

voltage select switch bypass.  There is no easy way to remove these switches with my equipment.  So I soldered 10mm bypass wires.

 

Do not attempt this unless you know what you are doing.  I am not responsible if you make a mistake.  Truly I was very surprised by this SQ improvement.  I wasn't expecting as much when I did it.  Well worth it.

[Quadman]

44 minutes ago, Toni-Mang said:

beside the transformer plugs.

I was going to remove those metal transformer bolts, but with a 6MM allen, I think, they are really on there, they probably used an aggressive loc-tite on them.  I applied some decent force and they would not budge, so I left them on.

[Quadman]

51 minutes ago, ted_b said:

My USB card is the Startech 4 port card (Asmedia 1142), powered by a JS-2, and although it might be a stumbling block for 32fs (don't know, anybody?) I just want it to shake hands with the May. 

Ted,  I seem to remember you saying your dac was a demo unit.  My guess is you have firmware 30.12 on it.  The Holo asio control panel will show you what firmware is on machine.  30.12 allows DSD1024 and PCM 1.4/1.5, But it has issues with non-intel USB ports.  So either move to regular USB port or flash firmware back to 30.14 and you should be good.  You loose 1024 and PCM 1.4/1.5 doing so.

[Quadman]

11 hours ago, ted_b said:

remove the ISoRegen from my USB cable setup

Ted, you didn't mention you had an isoregen in the chain.  I have one and tried to insert it last week.  Firmware 30.12 on my dac and they were unable to see each other so I removed it after rebooting both dac and PC.  The May does not like the IR with 30.12.  Another piece to sell.

[Quadman]

1 hour ago, ted_b said:

getting high frequency distortion (fatigue after a couple songs) on 32fs?

Are you listening to PCM 1.411/1.532 Mhz?  Why would DSD guy do that?  I don't listen long enough at those rates to get fatigue (what little I do, I do not note the distortion you refer to w intel MB).  The thinness and 2D images do nothing for me so I run back to DSD512, which has body, soul, 3D images, huge walk around stage and so much musical joy. 

[Quadman]

4 minutes ago, ted_b said:

that I do not convert formats; I like PCM as hirez PCM and DSD as up-modulated DSD

Wow, 99.9% of my catalog and Tidal and Qobuz are PCM and for years with Gustard X20U, T+ADac8DSD and now May L2++ I up sample all to DSD512.  Back when I first got the Gustard X20u to output DSD512 I was shocked at the improvement from 256 to 512.  512 was analog and 256 was really good digital.

[Quadman]

9 minutes ago, sledwards said:

DSD1024, AMSDM7 512+fs,

I'm a little short of horse power (10700K), but when no drop outs occur it sounds wonderful and I can't wait for 12th gen CPU which should handle 1024 with no cuda on a lot of modulators.

[Quadman]

3 hours ago, ted_b said:

getting high frequency distortion

Ted, I assume you are using HQP.  Try lowering the bits in HQP settings.  I am working in Listening room, so turned on system and noted that HF hash you describe with 20 bit output.  I lowered to 18bit and it went away.  Poly-sinc-XTR-Mp with ADSM7 512+ a fairly high computation filter.

[Quadman]

57 minutes ago, ted_b said:

1) are you saying you heard the hf hash at 20 bits in PCM?

2) are you saying that bit depth is an issue even when converting and playing back at DSD?

I typed faster than my brain worked.  Yes PCM 32fs, dither was LNS15 (not the ADSM7 512+ DSD modulator I said above).  With 20 bit output I heard the HF hash/distortion.  Then I remembered something Jussi said about bit output and lowering it for better playback (no distortion) so I lowered to 18 bit and HF hash went away.

 

Here's a quote from Jussi on March 22 I believe; ".There shouldn't be notable difference between16- and20-bit at 1.5M, or even at 768k...." He was referring to the noise floor.

 

I don't have a HF issue at DSD512 with 20 or even 21 bits, generally I keep bit output at 20 bits for my Holo.

 

 

[Quadman]

I was playing around with 32fs PCM the last couple of days and when I go from DSD512 up sampling to 32fs PCM up sampling the volume with PCM is LOWER than the volume with DSD.  Is this the same for you?  Wednesday evening while playing DSD512 I switched to 32fs PCM and had to raise HQP volume 6 clicks to get the same perceived volume as DSD512.

 

May manual only says PCM at 48K output 2.9V RCA and DSD 64x output at 1.45V (-6db), no mention of higher rate PCM output

 

 

[Quadman]

25 minutes ago, MichaelHiFi said:

The rate limit looks foreign to me as well. 

He's not using desktop HQP where as you are.  The settings are the same on desktop and bit rate is higher up closer to output in HQP settings.  For 1024 I would try 16-20 bits no more, auto may adjust down to that not sure.

[Quadman]

23 minutes ago, ted_b said:

Windows has high frequency hash at 32fs and 20 bit; 18 bit seems to tame it). 

Ted,  The PGGB website under dacs has this info...  It appears they recommend 16 bit at 32fs.

• Holo Audio May DAC (16FS/20bits** or 32FS/16bits***)

[Quadman]

28 minutes ago, dc-audiogeek said:

I have not had great experiences with silver cables

The only silver wire in the dac are those 4" long wires connecting the IEC to the PCB.  That's it no more, Just 5 little pieces 2 jumpers and the 3- 4" long pieces.

[Quadman]

No the transformers are not silver.  Per kte website

 KTE May Specs:
1. 100VA DUAL O-type(not Toroid) FLATWIRE (NOT roundwire) 6N Copper custom hand made audio transformers. (All models)

 

They are copper.  Only one kte of the spring had silver transformers.  May has copper.

 

If I had not bought used L2 (and had the skills to make it kte level) I would have bought kte, the sound is better than L2, and L2 is amazing.

[Quadman]

Everything, just more of it.  The may is the best dac I have heard music is so incredible through it.  L2 is amazing, blew me and my T+A dac 8dsd away.  Then upgrading, everything the L2 does the kte does a bit better. L2 owners don't know or care until you hear the kte on same system.  Is it worth $700 more?  It's better so what's that worth.