Holo Audio May


100+ Head-Fier
May It Be
Pros: + Changes the way you think about your setup and the way you are with music
+ May be the last DAC you need
+ Flexibility of separating NOS and filters
+ Value
Cons: - Price
- Non-adjustable 2.9V may be too hot for rest of the chain
- Unused volume buttons in remote
- Effort of using external filters (like HQPlayer) due to NOS
- Weight

This is my first review I'm going to write. It's been 10 years since I bought my HD800 and DNA Sonett. After that I've owned many combinations of headphones and amps and more lately, dacs.

Many people that are new in the space probably at some point hear the old saying : "If you want to change the way your system sounds, just change the headphones. They contribute most to how things sound.". I'm not going to say that this is totally wrong, but based on what I've learned during my journey, I would like to adjust that way of thinking a bit.

Today I see the chain as follows: the headphones as the magnifying glass, amps as a window (that can be magnifying, but glass anyway) and DAC as a TV. Recordings are movie files that we watch from the TV through these two glasses. Good headphones and amps reveal the picture in the TV. This is why some people say that some headphones "scale" with better system. I think those headphones always let the light go through the same way, but sometimes there just is nothing to see. If the window (amp) is blurry, TV is not 4K, but 720p or the movie file itself is poor quality (720p or just recorded with poor equipment - "home made"), it matters less how transparent the last magnifying glass (headphones) in the chain is.

Why this tends to take so long to realize? Because one needs to 1) have trained ears that are used to hear differences between systems AND 2) at some point end up listening a system in which all of these elements in the chain are high enough quality.

You need to listen
1) well recorded music
2) in FLAC/DSD (ie. lossless)
3) from a software that puts this through bit perfect (do not underestimate this, Windows absolutely ruins the music so that no high end system sounds better than mediocre)
4) from a TOTL DAC
5) through a TOTL headphone amp
6) through TOTL headphones
before you have a reference point for what true 4K sounds like.

Now, I will give you a story. I listened to Focal Utopia in a shop when it came out years ago. I had my HD800 with me in a shop and after doing some comparison between the two, I was "meh" and my conclusion was that HD800 was better or at same level, just different. However, a year ago the destiny got me together with Chord Qutest as it made my toe tapping (something that my Sony TA-ZH1ES didn't do). After I had familiarized myself with Chord sound, I started getting interested in TT2 and Dave as I felt like I was still missing something. I wanted to keep the Chord sound, but I wanted different soundstage and I felt like amps couldn't quite do the thing for me. Again, I went into a shop, tried Dave with HD800S and then compared that to Hugo 2. The difference was definitely there, but it was still more of a side wise move. Then I did something: I plugged Focal Utopia to those. That changed everything. While Utopia sounded good from Hugo 2, it was an absolute moonshot when plugged into the Dave. It wasn't colored, pleasant, even fun. It was just that nothing annoyed me and the staging was... right. That was a weird moment of realization.

I realized that there are dacs and there are DACs. I also realized that one needs to use TOTL DAC to hear the potential of TOTL headphones and vice versa. The rest is history. I searched around, read everything about dacs, noticed that many of the TOTL dacs are R2R dacs, Holo May was one, measured perfectly and had raving reviews (especially when used with HQPlayer) stating that it's better than Dave. Someone had May KTE in classifieds and my wallet was crying blood.

The Copper Teacher

So, The May.

The setup I'm using it with is:
Qobuz -> Roon -> HQPlayer -> Holo May -> SparkoS Aries -> Focal Utopia (and MDR-Z1R when I want to listen to soundtracks or when I need closed back)

HQPlayer settings I've mainly used:
DSD: -3dBSF | poly-sinc-ext2 | ASDM7ECv2 | 12288000
PCM: -10dBSF | poly-sinc-ext2 | LNS15 | 1536000
Settings: DAC bits 20 (dev's recommendation for May), 48k DSD enabled, Auto rate family enabled
Post processing: Jan Meier cross-feed / 650 / 9.5 (the same as Chord Hugo 2 on lowest setting)

For reference, my other current and past items:
Current: Softears Cerberus | Chord Anni/Hugo 2+2go | SPL Phonitor e
Past: Chord Qutest | Denon AH-D1000 | DNA Sonett | DragonFly Red | Feliks Audio Euforia AE | Graham Slee ULDE | Hifiman HE-400i/HE6se v2 | iFi iDSD LE | Sennheiser HD800/IE80 | Sony NW-WM1Z/TA-ZH1ES | Topping D30/A90

This has shown me a new reality. I feel like I have time before May and time after May. I can recognize that the music is the same, but everything is just so different now. Unfortunately I can't do side by side comparison to Dave, but right now I feel like that is a more side ways move. I could probably live with either one and be happy. I just think that I'm... happier with May. Why? Because while the Dave gave me the most non-annoying sound I've heard (though it WAS kind of intoxicating), May just... It has this grab. I don't need to go anywhere, I just want to be where I am when I listen to it. I just want to stay there. I constantly get these feelings that things are so right and it keeps delivering.

To me the question isn't about which one is better: May, Dave, MSB... The question is these vs. the world. The beauty of May to me is that while it's expensive, it's still a somewhat achievable port to this different realm (for the reference, I think my DAC is currently more expensive than my car).

But what do these do differently exactly?

I think after Chord Qutest -level, we are not talking about detail retrieval anymore or if the frequency response curve is flat. All of those DACs have that. The biggest differences are IMO in three things: staging, effortlessness and realism.


I think this is the reason I wanted to switch from Qutest to the next level. For a very long time I tried to get better staging with amplifiers and headphones, but hearing Utopia with Dave made me realize that the problem was that the staging wasn't good in the first place. Remember the TV comparison earlier? Now think that the staging of the DAC is the size of the TV. If the TV is 32", it's really hard to make the view impress you by trying to save the situation with magnifying glasses. What May and Dave both do (compared to lower level dacs) is that the TV is 100" in the first place and the rest of the chain just need not to ruin it by squeezing it together. I much, much prefer using May (big stage dac) with Focal Utopia ("small stage" headphones) vs Qutest (small stage DAC) with HD800S ("big stage" headphones), if that makes sense. The end result is much more natural, pleasing and effortless. Also now the stage can be at the same time intimate and huge (when the music calls for it).


May is effortless in how it presents everything (a term I've heard many times and it feels very natural to use it in the case of May). However this I think I got already to some extent from Chord TT2, though not exactly the same level. I think this is somehow related to the staging. It's like, when there is space between the instruments not only in x,y axis, but also in the z-axis as well, it's more natural for brain to distinguish and follow (=process) different sounds and one doesn't feel that one needs to extract all the information from a small and dense ball of sounds in a hurry. It may be that this sense of effortlessness comes from something else as well, but this is how I would put it.


I think this is the hardest to explain of the three. Also I think this is where May does some very special magic and is one of the secret sauces behind May's success. I think this is what gives May its "grab" and it kind of works subconsciously. One doesn't need to listen to May for very long before one notices this feeling that something is very right. For me this didn't do the immediate classical "you start smiling" -trick but instead something just talked to me, quietly, and reached very deep. This became even more apparent when I tried to change something or leave the listening spot. I suddenly had this very strong urge not to. It started to feel like I would leave the presence of a friend.


Then, I think that as a reviewer it's my responsibility to mention a word or two about the NOS side of things. You will find a lot of information while googling around and watching other reviews of May, but I'll mention something very briefly. May is meant to be used in NOS (non oversampling) mode. Most of the DACs do some internal oversampling before they actually convert the bits into sound and also May does have this capability, but it's not actually its strength. Its strength is that its implementation of NOS is not only true NOS, but also a very good one. While it sounds great just in NOS mode as well (with good recordings), the benefit that NOS brings is that it separates the DAC itself and the oversampling filters it uses. One can use MScaler or software like HQPlayer that have state-of-the-art filters that are probably better implemented than the ones in DACs. Your computer most probably also has more computing power to use higher quality filters. With May you also don't pay (much) for the filters of the DAC that you may not want to use anyway. I've found that the combination of HQPlayer and May is sublime and provides a lot of flexibility to the sound. One can fine tune the sound with different filters and noise shapers in HQPlayer to match the taste (and mood) of the listener. It's also a great learning experience to dive into this world. I also want to mention that my review of May is kind of strongly coupled with an assumption that one uses HQPlayer or some other proper oversampling software/method. Personally if it was a requirement for me that the DAC must be "plug and play", I would probably watch elsewhere, like Dave. While to my ears May sounds really good in NOS mode with good recordings, it also does sound sometimes harsh with bad recordings. Good oversampling simply makes it versatile to be used with anything and more often than not, makes things sound better.

The wish list

For May 2.0 the wish list of things isn't long, but there are two things.

First: I'm using it with sensitive headphones and I've found 2.9V output to be a bit hot sometimes. With Utopia even the lowest -52db setting of SparkoS Aries is already quite loud and I unfortunately can't use my Softears Cerberus with this setup without some external attenuation. Luckily with HQPlayer the problem is much smaller as I can adjust this with headroom and HQPlayer does this quite well. However to me, especially at this price point, digital attenuation<lower gain. Also with software based attenuation I'm a bit afraid that some system ping goes through +10/13db louder than music (or I simply forget to turn down the dial after switching away from HQPlayer). That would be very unfortunate if I was already listening at very loud levels.

Second: The remote has volume buttons while May doesn't have volume control. This is a very small thing for me, but still. It feels strange.

Ending words

I think I could keep talking for days, but I'll just stop here as I feel like I've mentioned and explained the big thing I wanted to talk about. Everything else is nice and right, like timbre, detail retrieval, black background, good USB implementation etc. However I kind of had expected those to be good already when I came from Qutest. To me the one thing (which also is a big thing that changes basically everything in the way I see the system) where these TOTL DACs differ from other dacs most, is how they present the soundstage. Then what's special to May is that 1) it's a R2R dac and 2) it's a NOS dac, 3) it basically measures perfectly and 4) it has this magical grab. If you want to up your DAC to state-of-the-art TOTL, are not exactly swimming in cash and NOS rings right bells for you, you owe yourself to at least demo May. It's an amazing unit that will not be the bottleneck of your system, 100%. If you just want a plug-and-play TOTL DAC that comes with good filters already baked in, you may want to look somewhere else. If you are are going to say that Topping E30 measures the same, buy Topping E30 and be happy. If you are swimming in cash, do whatever you like.
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Quick question... in addition to your comprehensive headphone review.....thank you.....did you experiment with various cable formats...xlr vs rca, etc.?
No, I have only experienced with RCA. The reason is that RCA is already a bit too hot for me and XLR has double the power. However, the reports I've read have said that it should sound the same or no night/day difference (like with some other dacs).
I think this pretty much sums up my descriptions too. Thanks for sharing.
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