May Dac = “The possibility of.”
The May DAC is here! over 3 years waiting and tremendous R&D to achieve a new level of performance and sound quality that sets a new standard. Ultimate endgame DAC. Natural Analog sound with no compromise. Having the best measurements of NOS R2R Dacs. And delivering our intoxicating sound signature that HoloAudio is known for.
Currently production time is estimated for about 4-5weeks from time you place your order. We appreciate your patience and understanding. We will likely deliver before this time, but this is an estimate for new orders. Inventory shown on the website is to control sales volume only.
Here at Kitsune HiFi, we have three versions of the May DAC. Below are the three levels, and KTE being our no compromise model with all options:
Prices are as follows for May lineup:
L1 MAY = $3798.00 + S&H
L2 MAY = $4298.00 + S&H
KTE MAY = $4998.00 + S&H
Some noted features:
The May DAC (all three models) will also support DSD1024 native and PCM 1.536MHz output! Theoretically it can do DSD2048 and PCM 3.072Mhz however is untested at this time. Also, we have worked hard to reduce the common click noise with all dacs when switching from DSD to PCM. This sound click sound has been reduced significantly with a special circuit design. The May DAC has the new and exclusive USB Enhanced module which has our FPGA with the new Titanis 2.0 and custom firmware to improve USB Eye Pattern and reduce latency to near zero as well as reduce jitter to very very low levels. The USB module has completely new code written to optimize performance and reduce latency significantly. Low frequency performance (-40db) is also improved. The “enhanced” USB xmos module is twice as powerful/capable as the one that is used in the Spring2.
New improved power supply circuit with high performance multi stage regulation circuit using Rubycon ZLH caps, Panasonic FC, Vishay Caps or L2/KTE models with our exclusive HoloAudio Branded Caps (KTE model unique custom proprietary caps to replace Vishay caps)
We are no longer using common LVDS chipset and are now using a custom 4way circuit that isolates each line which further improves sound quality. such as the MCLK is isolated from data line and this improves jitter spec. Also there are TWO i2s ports in the May dac. Each one can be individually configured pin outs to support all i2s products on the market.
The May and KTE version of the May DAC also is with a CNC machined aluminum remote control! Standard with all three models.
The KTE version has OCC copper wire replaced with 1.5mm pure silver wire. 1.5mm Silver wire is soldered direct to the pcbs with highest grade audio solder. Silver Rhodium Faston connectors used at IEC input.
The May is a DUAL mono DAC. so there is a dedicated Dac Module for Left Channel and a dedicated Dac Module for Right Channel. Also each channel is individually powered by it’s dedicated Otype FLATWIRE transformer found in all three models. We have found after careful testing this new transformer type outperforms ALL transformers we have ever tested to this date. Near zero leakage, improved dynamics and overall spectacular performance. They are handmade for this dac specifically and delivery world class performance you would expect.
May dac also has a new screen on the front that appears the same as the Spring2 on initial glance…. Font size is bigger than Spring2 but smaller than Spring1. Also you can see the CD track-time information is displayed when using spdif inputs!!!. This is done by extracting additional data from SPDIF. This a part of CD red book standard but nobody notices this and often forgets this cool feature or doesn’t know how to extract the data!. This will lead a fashion for other DAC developer to support this feature… customers will surely love this feature albeit subtle. The screen is much better contrast and viewing angles and one of the first things one may notice.
The May also has a front power button now! It’s been a request by many customers and gone are the days of a good old reach around to get the dac to be turned on! As mentioned before above… The dac has a soft start circuit!! So don’t fret, it takes a moment for it to charge up and pull power without blowing the fuse!! It actually uses the same exact value of fuse that our spring1 and spring2 has! But two transformers! If we don’t have a soft start a couple issues can happen… one being a blown fuse from power surge, and another simply having possible pop noises. No chance of these things happening. We have carefully designed the circuit to have a zero compromise design.
Technical Information about our Custom PLL circuit:
Notable features of May Dac.
- The new generation of linear compensation technology solves the accuracy errors caused by resistor
tolerance, after compensation, reaching a variance of 0.00005% tolerance accuracy.
- Proprietary anti-jitter technology that provides a full amplitude of anti-jitter without increasing noise floor
and other undesirable effects.
- Based on this new generation of technology May “梅” can provide a SINAD of >115dB and a dynamic range
of >130dB, which represents the performance limit reached by today’s most advanced R2R architecture
- Using the ultimate performance of PLL+FIFO technology, provides 0.1Hz Third-Order low-pass ability to
inhibit jitter. It also uses a high-performance femtosecond VCXO as the PLL clock source. Under the premise
of being almost immune to the front-end jitter, it can also lock up to 1.5us-2us @ 1KHz signal with high
jitter. (It can lock up to 1.5us-2us @ 1kHz signal with high jitter on the premise of almost being immune
- Dual Mono DAC L/R channels are independently powered by their own dedicated transformer in the PSU
chassis. This provides better channel separation and more accurate sound stage.
- Official Support USB and I2S up to DSD1024 and PCM1.536MHz sample rate.
- The USB interface uses proprietary firmware with ultra-low latency, a highly reliable data transmission, ideal
USB eye pattern measurements that contributes to 2-4 times higher performance than official firmware.
- Two sets of independent HDMI-I2S input interfaces are provided, and each set of I2S has a four-way
independent circuit, as opposed to standard LVDS chip, making I2S clock signals subject to lower
interference and lower jitter. In addition, each group of I2S inputs can be configured with specific pinout
configuration, making it compatible with most of the HDMI-I2S digital devices on the market.
May drivers for Win7/8/8.1/10 – v.4.67.00 +all firmwares for all products – Click Here to Download
NOTES for new v4.67 Driver (this is a major release with firmware update for each model, May, Spring2 (two versions), Spring1, Cyan DSD or PCM.
Please read more about
(MUST READ article to explain why we recommend NOS)
*Please follow the Head-Fi forum thread here
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Please read some reviews of our Spring1 dac below: (note the Spring2 is only improved over the Spring1 design and sound quality, its our well respected “house sound” that HoloAudio is known for. May will be reviewed soon by MANY reviewers in the near future. Stay tuned for updates! However, below are reviews from Spring and Spring2 dac.
Dimensions per chassis (2 total): 430 mm (W) * 300 mm (L) * 55 mm (H) additional 12 mm for machined feet (for each part, two of these chassis stacked on each other)
Weight: 18.0 kg Approx for both Chassis or about 39.68Lbs
Power Consumption: 60W
Accessories included: power cord, remote control, DC Power Cable, Package includes DAC only + Remote +DC Cable – NO Batteries in remote to speed up customs clearance.
WARRANTY – 3 years warranty, both parts and labor, cover one way shipping (return shipping once product is confirmed a warranty claim). Be sure to buy directly from HoloAudio or authorized reseller and we recommend to buy from HoloAudioUSA<– this is KitsuneHiFi 😉 – Support is given from the source you choose to purchase from.
Click HERE for instructions on how to open the chassis properly with photos and step by step of which screws to remove and which ones to not remove 😀 Updated instructions for MAY will be updated soon. the above link is for Spring2 which is nearly the same, except one or two screws difference on back panel.
Download Windows System Icons HERE (image of Spring DAC, and kitsunetunededition logo)
FoobarDSD support HERE
Download May DAC Hardware Manual HERE
Download May Software Manual HERE (includes Foobar2000/SACD will need FooBarDSD if you are planning to use FooBar2000) – FooBar is totally optional (available soon)
OFFICIAL May DAC Signed Windows Drivers +firmwares v4.67.0 Windows 7/8/8.1/10 – ASIO – HERE – stellar performance
note: WIN7 users may have issue if you don’t have the most recent hotfix for SHA-256bit code signatures. By default Win7 only supports SHA-1 signatures, yet SHA-1 is obsolete and this hotfix is very important for security reasons. Win 8 and above have SHA-256bit by default. Some users reported these drivers not installing properly, so be sure your Win7 is up to date, or download the hotfix here (KB3033929) : https://support.microsoft.com/en-us/kb/3033929
This is special order item (will show “in stock” if able to order, this means we have the parts available for this dac and the order can be placed), with a typical 4.5+ weeks (estimated) delivery time to USA customers. Other voltage options than 110V (ie: 220/230/240V) may delay order an additional week. We will give you current estimate upon receipt of payment if it is different than the quoted 4.5+week estimate, and can be cancelled if you choose not to accept the terms to wait for the production/shipping times. After you accept the terms, I will place the order with Holo Audio directly, as the order is considered a special order item there will be no cancellations or refunds if 48hours past date order was placed. The product is guaranteed not to be DOA and has multiple levels of quality control testing before it’s shipped out to you. We are confident you’ll be happy with your purchase.
NON USA customers please contact us for quote on shipping costs. Please include your full shipping address and phone number along with voltage requirements when requesting to order this dac. The same terms apply and estimated production times quoted above.
Shipping estimate varies, it’s best to email us for a current quote. (items in stock are only allocated for this batch, if you buy now, it will secure your position in our next batch)
if you are in Europe, please contact our European Authorized HoloAudio Dealer for the best service and support in your area, Magnahifi.com
– Kitsune HiFi
“NOTE: Be sure to say in notes what volt ac model you need, USA is 110 volt ac standard etc. – Also note if you ask for special voltage transformer that it can delay your order up to a week longer.”
Kitsune HiFi carefully chooses products that we want to offer to our customers and be unique and/or stand out from all these audio supply stores. Jeff Zhu is a very talented engineer and is the brains behind HOLO Audio. Some say he is the man behind the curtain and he has certainly impressed us with his knowledge and his newest line of products that surely will leave you impressed too! The May DAC is the most recent product and is capable of DSD native on an Discrete Resister Ladder DAC! This May DAC is capable of DSD1024 native and actually running on his bespoke discrete ladder DAC! This is a unique custom build discrete resistor network dac with linear compensation and advanced architecture based on R2R however we don’t refer to it as R2R since the design is far superior. This is our second discrete DAC that has linear compensation and this allows for ultimate music reproduction accuracy. Dual MONO R2R DAC Module resistor network with advanced architecture for PCM w/Linear Compensation. Also Dual Resistor Ladder network with optimized architecture specifically for DSD! We will be offering the first May DAC’s in the USA and the KTE/Kitsune Tuned Edition is no longer just exclusive to us. We have licensed the build as being the ONLY authorized modded edition of the May DAC by HoloAudio. This means our authorized dealers will carry our KTE May! And if you buy from a dealer you will get support from that particular dealer. Many may continue to choose Kitsune HiFi and will receive our excellent customer service that we are well known for.
You may be asking… well what is so special about this DAC? A Discrete R2R DAC with linear compensation…what is this?
There’s an additional R2R resistor network in the May DAC, that compensates the main R2R ladder. It works like trimming, but trimming is to change the resistor value. This additional R2R ladder is digitally controlled and will accurately compensate the resistor tolerance reaching a variance of 0.00005% tolerance accuracy. . For example, the MSB of 16 bits should have the value of 32768, but due to tolerance, it represents 32700 in real world results. Then that additional R2R ladder will compensate 68 into it. Thus it now becomes 32700 + 68 = 32768. What this means is that it’s likely the most precise Discrete DAC on the market with near flawless linearity, lowest THD and highest SNR of any NOS DAC. The sound is simply something you must experience to fully realize how special this DAC is. It’s a patented technology exclusive to HoloAudio. KitsuneHiFi is also Holo Audio USA and proud to bring you this DAC.
This new DAC “May” is the design of a new generation, it’s HoloAudio’s finest technology all designed by Jeff Zhu, the engineer behind these great products. It’s a full discrete R2R type of audio decoder and does not have off the shelf-DAC chip! This is a bespoke custom-designed core DUAL MONO DAC modules that are truly a breakthrough with technology for any DAC chip today. The May is here to achieve new heights, new dynamics and simply a full spectrum of audio to please the aural senses.
Holo Audio is the world’s first to support DSD natively on Resistor Ladder DAC, so far the only one. This is not the DSD converted to PCM before digital-analog converter, but directly by the discrete components of the DSD digital to analog converter. Supported currently on MAC (DOP)and Linux (DOP), and Windows/PC (Direct Native and DOP). Please note, the word ‘R2R’ is the name of a kind of architecture of resistor ladders. This architecture requires less resistors yet still is capable to deliver more than acceptable performance. Most DACs in the industry use this architecture. The DSD Dac module resistor network of May Dac does not use R2R architecture for the DSD, more specifically it uses a very specific architecture which is optimized to perform DSD data to analog. So to be entirely accurate the DSD part of May Dac is using resistor ladders, not R2R..
Info on Red Nano Fuse type used in KTE May model:
Fuse Type for L1 and L2 May :
Shurter Gold fuse type
2A SB 5x20mm (220v) and 4A SB 5x20mm (110V)
May’s input and output interface:
- Digital input interface includes
- Enhanced USB (ground isolation) + Titanis 2.0 circuit + KYCON industrial High retention USB Connector (improved impedance spec) – Proprietary inhouse firmware w/ ultra low latency performance. Ultra low noise voltage regulation
- RCA coaxial
- BNC coaxial
- optical fiber/Toslink
- I2S (HDMI) – improved ultra high performance 4way custom circuit (NOT traditional LVDS chip anymore) backwards compatible
- I2S-2 (HDMI) – improved ultra high performance 4way custom circuit (NOT traditional LVDS chip anymore) backwards compatible
- All digital input interface supports DSD (DOP mode).
- Analog Output interface: single-ended, balanced.
May DAC R2R structure and design + Input/output Stage
Modern and popular delta-sigma type DAC differs from R2R within one clock analog value can recover a sampling point, and the delta-sigma is used to represent an analog signal after passing through oversampling and high-speed digital switching 0 and 1. In comparison, the conversion structure of R2R is most direct and pure, but delta-sigma is essentially a digital chip, high-speed digital signals 0 and 1 switch to the low-pass filter to process the analog signal and this process is prone to various problems, produce digital sound (digititus) and also in the super-sampling process will inevitably cause some ringing and distortion. But DAC R2R structure requires high-precision resistor network which the cost can be very expensive. And the digital delta-sigma DAC chip in comparison is very low cost. Patented R2R technology. This is the first discrete DAC that has Linear compensation and this allows for ultimate music reproduction accuracy. Dual R2R ladder network with advanced architecture for PCM, and Dual Resistor Ladder network with optimized architecture for DSD!
I/O stages: There is an Op Amp used for input stage and discrete component used for the output stage. The discrete output stage is working in pure class A. It’s BiPolar Junction Transistors, direct coupled.
A common question we get…” Why do you use an Op amp at the input of the DAC?”
The input stage with an opamp is a good choice. It has a paired transistor input by the nature it is manufactured. But an opamp for the output stage is limited due to it’s size and the thermal capability. Also, no one will offer an opamp with class A output as it’s efficiency is so low. So an opamp used as input and discrete output combined together will have an advantage. It doesn’t mean that all discrete is not good. Actually, if we need to achieve enough low distortion. It needs at least 30-40 transistors. Which not only will it be huge and waste of space but it will also be too costly. I mean, to beat the opamp’s performance, a simple discrete architecture is not possible, although an all discrete design looks beautiful.
The true balanced DUAL MONO circuit design
XLR is using all of the circuit and RCA is just using half of them. The balanced output has better performance (THD, noise) and also better common mode rejection rate. If you’re listening environment contains interference, either from AC power or from EMI/RF then you will find a full balanced system can really help significantly.
With diverse and flexible sampling mode conversion mode
1: NOS mode: has no digital oversampling, the raw data is directly converted to analog. Because digital oversampling will produce time-domain distortions, such as ringing, NOS avoids these problems. Generally NOS mode’s other performance indicators have a significant impact, but the Spring 2 is designed to allow top performance while in NOS mode.
2: OS mode: PCM is over sampled to PCM at a higher frequency, DSD is over sampled to DSD at a higher frequency, and then digital is converted to analog.
3: OS PCM mode: in either PCM or DSD the data will be oversampled to PCM and then digital is converted to analog.
4: OS DSD mode: in either PCM or DSD the data will be oversampled to DSD and then digital is converted to analog.
What are the May’s sound characteristics? :
One of the strong points of the spring is the spatial sounds stage presentation. It’s very wide and precise. It never sounds congested like many DACs. The high end is very detailed and never harsh sounding. It has the R2R goodness that many have come to know and love. R2R has almost a cult like following and this DAC will surely become a sought after DAC. Everything comes effortlessly for this DAC. Bass is layered and textures, quite full and present without ever masking over the sweet mid tones that are produced. One special thing about the May is its amazing voltage regulation circuitry that better than 0.2uV output noise! This along with the FLATWIRO-core transformer helps regulate the purest power which translates to audio clarity and accurate reproduction. It must be heard to appreciate and come to love its sound. If you must have the best and nothing compromised then we would suggest the KTE or Kitsune Tuned Edition.
May Dac UPGRADE / Spring1 & Spring2 TRADE-IN Program Official Rules:
Tim & Dawn Connor – HoloAudioUSA and KitsuneHiFi
We operate under strict business ethics and principle values. Our company motto we are always proud to mention to our customers, “Time will tell…” and this means that our products will earn the respect in a matter of time once people get their chance to test it themselves. Many companies need fancy buzz words and marketing to sell their products, we truly only need our customers to try our products and share their experience with others. Word of mouth is how our business thrives and we have many happy customers! We encourage others to try all the competition in the market and directly compare and see what type of value you are receiving. We are confident in our products and know that in time, our products will sell themselves once people get a chance to try them. We offer tremendous value and quality without sacrificing on performance.
Jeff Zhu – HoloAudio – founder/engineer
Jeff Zhu is the man behind this engineering achievement. Below are some comments that have been shared by Jeff to better explain this dac in his own words. Holo Audio is founded by Jeff Zhu and the USA division was a partnership formed with Tim Connor and his wife, Dawn Connor.
A little note from Jeff:
Many have asked about how does a discrete resistor network accurately reproduce sound. This email is a good read for those who want a technical explanation on how Jeff was capable of achieving flawless linearity and ultra good specs on THD. This was a reply to a customer who had a technical question about resistors and their limitations.
“About the resistor tolerance, his word is partly right, but not accurate. The MSB of 16bits value only represent 32768, not 65536, all 16bits is 65535, but the MSB is only 32768. There are techniques to reduce this requirement. For example, segment+R2R, using segment into the first few bits, then r2r for the rest of them. Rockna is segment+R2R, TotalDAC is all R2R. And you can see, Rockna’s THD spec. is much better than Total. Total uses foil resistor, but they used the simplest architecture. That results an unsatisfied test performance. To my opinion, it’s some kind of wasting foil resistors. Soekris also uses segment+R2R. MSB’s old model is all R2R, but I don’t know about their new models.
Anyway, There are ways to improve the performance, the segment+R2R is one way. Trimming is another way. There is an additional R2R ladder in Spring, it compensate the main R2R ladder. It works like trimming, but trimming is to change the resistor value. This additional R2R ladder are digital controlled and is to compensate the resistor tolerance. For example, the MSB of 16 bits should have the value of 32768, but due to tolerance, it represent 32700 in real world. Then that additional R2R ladder will compensate 68 into it. Then it became 32700+68=32768.
Actually there are other ways to improve performance, I just told you two stories. There are more stories behind the design. It is really hard. I must count every via holes in layout, every PCB wire has it’s impedance and must put attention on it. A via hole can be 50 m Ohm, it is 1/20000 of 1 kilo-ohm, and you see, it covers 32768 which is the MSB of 16bits. Also the switches has self-impedance which is about several ohms to 30 ohms. If you find this issue. Maybe you will go crazy, it seems to be an impossible mission. But a good designer will overcome all these problems. It’s our value at HOLO Audio.
All the resistor tolerance, switch impedance, line impedance, via hole impedance, finally reflect as linearity. There is a chart that shows Spring’s linearity, it’s excellent. But I suggest you to look at THD performance. Bad linearity must result a bad THD performance. But good linearity doesn’t mean there will be good THD performance. THD is dynamic performance, more critical than linearity which is a static performance.
If you look at the THD performance, you will find Spring to maybe the best among those competitors. I’m applying a patent which contribute a lot of that performance. But I can’t tell you how. It’s confidential now.
And another note on Linear Compensation. As Some have asked what happens when the Resistors values change over time? Jeff responds:
No matter it is a digital switch or analog switch, they are built by transistors, can be either bjt, mosfet or jfet. They have self-impedance call Ron(impedance when at on state). If we expect a lower Ron, the a bigger transistor is needed. But bigger transistor has bigger self-capacitance that will cause switching speed to be lower. So there is no perfect components in the real world.
About long term drift, the modern resistor technology has made it much better than older process. But the most important thing is, we don’t care absolute drift, we only care relative drift. That means, if all resistors are drifted in the same direction and same speed. Then it will be no impact for this application. So, we make sure to use the same batch of components in a single board. That will minimize the problem causing by long term drift.
As I mentioned in the earlier email. Spring is not using trimming, but using compensation. Not matter it is trimming or compensation, their goal is same, to make the resistance much more accurate so the linearity and distortion can be improved a lot.
Also, another customer asking about the oversampling, Jeff replied and has some good information to those who are curious.
The oversampling is done by AK4137, ‘OS PCM’ converts the input stream to PCM no matter it is PCM or DSD, then send to DAC. ‘OS DSD’ converts the input stream to DSD no matter is is PCM or DSD, then send to DAC. ‘OS’ over-samples the input stream. If it is DSD input, it over-sample to DSD256. If it is PCM input, it over-samples to PCM384K or 352.8K ‘NOS’ does no oversampling. send the input stream directly to DAC module.About DSD ‘native’, it is the way the USB transfer the stream. You know DOP, which is DSD Over PCM. DOP put the DSD into a PCM stream. At the receiver end, it just unpack the PCM stream and get the DSD back. DOP does NOT change any bit of DSD stream, just sending it with the package. So it waste some data rate. At the same data rate, DOP is 1/2 of DSD native, the other 1/2 is the package. So DOP and DSD native are all bit perfect. The DSD stream sending to DAC is all the same.So, now you should know, DSD native is just about the way it transfers the stream. Not describing the way it does digital to analog conversion. At the DAC stage, the DSD stream can convert to PCM then do the final digital to analog conversion. Actually, most DAC chips do this inside the chip. One point needs to be remembered, DSD streams can’t do volume attenuation. If this chip can do digital volume control under DSD mode, then is must converted to PCM already.Let’s go back to Spring. If Spring works in ‘NOS’ mode. There is no
oversampling, no conversion, just the original data doing the final digital
to analog conversion. I will not explain how it does PCM conversion, you
should already know quite well about it. There is a lot of resistor ladder
DAC, they are born to do this. I just explain how Spring can do ‘discrete
DSD conversion’. Actually it is like DCS and CHORD. If you looking to DCS
and CHORD’s PCB, you will find ‘discrete DSD conversion’ is also using
switches and precision resistors, like resistor ladder DACs. So, no matter
it is ‘discrete DSD conversion’ or ‘discrete PCM conversion’, they all use
the same discrete devices. Just work in different architecture. That makes
possible to combine these two modes in one device.