HOLO Audio Spring DAC: Affordable discrete R2R Multibit Dac, could be a winner.

Many manufacturers are going back to R2R Multibit d/a conversion, a good portion of audiophiles are saying it sounds better than the cheaper d/a conversion of Delta Sigma, (1 bit), Bitstream, Saber. etc.
And it says it uses dual R2R’s Multibits to support DSD natively!!? 

Product Description:This new DAC.”Spring” is the first design of a new era, a milestone for HOLO Audio’s own Jeff Zhu. 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 DAC module and truly a breakthrough with technology for any DAC chip today. The Spring is here to achieve new heights, new dynamics and simply a full spectrum of audio to please the aural senses. This Dac has been called the poor mans Total Dac / MSB / Wavedream / Chord Dave Etc. It plays with the big boys.


Looks amazing inside for $1,700. Schiit Yaggi better watch out!!!!

Cheers George
This looks like a very good designed and implemented product. Their level 3 version could be quite special. It offers upgraded Jensen capacitors in the power supply and a silver wired 100VA transformer (green label). No question that higher quality transformers and power supply capacitors make a significant difference. Internally it appears to be very well built. Interesting the builder recommends the Audio Horizon Platinum fuse as a desirable option. True R2R ladder architecture. Isuspect that this DAC (particularly the level 3) could be exceptionally good sounding . I'm curious as to their approach to I/V  conversion (an important variable). Their pricing seems very fair given what’s provided. I wish them well.
How do they do DSD if it is true ladder dac? Do they oversample. This would ruin it for me
You raise a good point regarding DSD.  If the implementation of this DAC is high level it could be excellent for Redbook CD playback. 
How do they do DSD if it is true ladder dac? Do they oversample. This would ruin it for meAlan
I’m no digital expert, but I think it’s the same way as MSB do it on their mega dollar flagships with multiple multibit dacs, that are also discrete multibit, yet able to do native dsd.

But there's no decent music available on native dsd anyway so why bother. And the PCM redbook 16/44 or 24/96 that's been converted to dsd "Hirez downloads to me sound at best average.
Cheers George
Just looked for purchasing, and all three versions are out of stock.

Cheers George
I'd enjoy  the opportunity of  directly comparing their level 3 Spring DAC with my organic sounding Yamamoto DAC. I had the Metrum Octave DAC (R2R/multi bit chip  concept)a few years ago.  It was in fact very good but head to head I preferred the Yamamoto and sold the Octave.   The Spring DAC could possibly be better than the Metrum. It'd be an insightful endeavor. 

FYI, I've talked with HOLOAUDIO this morning and a small amount of jense caps have become available. But I'm working on how many of these dac's can be acquired,  Those who email me with their interest will be first come first serve. I'm posting a message this morning with an update. 115V is typically what we sell as KitsuneHifi is a USA based company. But other requests can be made via email. Thank you,

-Tim Connor
Tim, good of you to drop by.
Those who have indicated their interest can start ordering now.
A very big Yay for them!

This morning I just got word from HOLOAUDIO HQ that they are back in stock, earlier than anticipated. but a very limited supply
Very much looking forward to listening impressions from those who finally get this dac into their homes. :)

The review is with headphones come on. I can really tell what that dac can do.
I think listening to a pair of HD800's or even HD650's with a good head phone amp is very revealing, once you've given them a chance and gotten used to them for a while.
At first yes the head-space thing is a bit disconcerting, but shut the eyes and lay back with a nice drink, and they can be very very good. (And no you don't need more drink.)
Cheers George
Has anyone placed an order and received this dac?
Would be nice to hear impressions through loudspeakers too.
I am a end user in hong kong , mine is a level 3 version (but my jensen cap is still on the way), and  i have option to upgrade the audionote silver isolate transformer which in front of the digital in, which make huge improve over the cheap one inside, before that i am a metrum pavane owner, i am very happy with pavane , it provide a very smooth and organic sound , strong and defination bass, sell it because to save some money, and for the holo spring performance, it really close to pavane but not better, but consider the price , it almost outclass similar competitor, and i am waiting for my jensen to make a final judgement
It uses the AK 4137 chip which is third in the "Velvet Sound" line-up of chips from AKM, used also in all Esoteric players and dac's.
Interesting that the AK 4137 can be implemented as R2R.


I am a end user in hong kong , mine is a level 3 version (but my jensen cap is still on the way), and i have option to upgrade the audionote silver isolate transformer which in front of the digital in, which make huge improve over the cheap one inside, before that i am a metrum pavane owner, i am very happy with pavane , it provide a very smooth and organic sound , strong and defination bass, sell it because to save some money, and for the holo spring performance, it really close to pavane but not better, but consider the price , it almost outclass similar competitor, and i am waiting for my jensen to make a final judgement

Hi Gary, are you able to elaborate on the Audionote silver transformer option as I am in the process of ordering. Thanks, Greg
My hong kong dealer tell me that, most digital device , there is a digital isolation transformer locate before the digital in/out ( aes, bnc, coaxial), many company use very cheap one $ few cents, and i upgrade it to us$170 audionote pure silver transformer, but it is only benefit in these 3 digital in , useless if u use usb or i2s, the transformer pic in blow

Ah I know which you are talking about, thanks for the info.
Im very interested on your thoughts beyond your earlier comments on its sound as there is just so little information on this dac. Have you got the Jensens installed?

Thanks again for your time and thoughts.
as i know , AK4137 is only for SRC, it is bypass in the nos mode

nos mode should be optimal for pcm as I have found with my own Esoteric dac(N-05 which uses the AK 4490 chip) set at no upsampling plus pcm filters off.

Looks like for dsd, the Spring dac needs to be switched out of nos mode to OS(oversampling) or OS DSD mode as stated in the CA forum thread. This is similar to the Esoteric dac.
Getting a bit confusing here, "discrete dsd" vs. native dsd........

From Jeff Zhu, the dac designer :-

"If Spring works in ’NOS’ mode. There is no oversampling, no conversion, just the original data doing the final digital to analog conversion..........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."

Hello gary9413 ,
You have assembled a very nice and well thought out system.  I believe choosing the Spring DAC level 3(upgrade capacitors and transformer)  was a good decision.  I sincerely believe that opting for the highest quality transformer/caps offered  are the type of choices that make a true difference in sound quality. Your system  IMO will be capable of resolving the improvement these better parts provide. I'm confident that you'll have no regrets. I like the fact that the transformer is a robust 100 VA. Most DACS use the smaller 15-30 MA size.

The player is aurender n100s , in between n100s and spring , there is a bryston buc-1 usb converter , i am using AES in , 
I haven't seen anything specified regarding the type of I/V conversion circuitry used in the Holo Spring DAC, if that's what Charles is asking about.
Regarding I/V conversion, I have no specific knowledge of the HOLO DAC’s design beyond what has been posted and linked to here, but it seems to me to be possible that it doesn’t need any. A ladder-type D/A converter circuit, including "segmented" ladder types such as the HOLO appears to be, can be designed to provide either a voltage output or a current output from the ladder itself.

Of course in either case an analog output stage of some sort would most likely still be required. Although if I recall correctly one of the very expensive upper echelon TotalDAC designs manages to do without even that, and by using a multitude of D/A converter circuits in parallel can apparently provide adequately low impedance for many applications without having any active devices between the ladder and its output.

-- Al

Yes I was referring to current to voltage conversion (I/V). It is usually via a resistor (passive), Op amp or sometimes a transformer (Audio Note). However as Al wrote R2R ladder circuits can have voltage output rather than current output. I’m just curious how this interesting DAC achieves its output.

A good friend of mine decided to order this DAC (level 3 version ) and should have it in a few weeks. He has a Bricasti SE which sounds terrific in his system. I think that this is going to be a interesting comparison. If possible I’d like to hear it in my system and compare to my Yamamoto YDA DAC. It’d be fun to hear this DAC in two very differently assembled audio systems. Well common ground is we both have "class A amplifiers". I have  8 watt 300b SET mono blocks and he has 600 watt Krell FPB mono blocks 😁.
It would be extremely helpful to hear how both of those comparisons go, especially against the Bricasti SE since that's a more widely known product. I look forward to your further thoughts on the Holo DAC.
Enjoy the tunes!
- Bill

Hello Bill,
The primary comparison will be between the Spring DAC  and Bricasti SE. The Yamamoto is definitely a lesser known Japanese boutique product. It has been built by a very talented designer and sounds superbly natural and is musically/emotionally engaging. This comparison would be optional. 
The Yamamoto YDA-01 dac at $2450 would be a better comparison with the Spring dac than the Bricasti SE at about 4 times the price of these 2 products.
Post removed 
In theory you’re right regarding price category and expected performance. However actually listening to components in your system proves otherwise. I’ve learned that price/performance isn’t a linear relationship. The friend I referred to earlier had the highly touted Playback Designs unit(16 K at the time) in his system several years ago. The truth? It was clearly outperformed by the far less costly Mod wright modified Oppo 2 chassis player! This was with both CD and SACD.

Generally speaking you get what you pay for, in High End audio there are definitely exceptions to this mantra, no question. This has taught me that you must listen to audio products when ever possible. Speculation and expectations can be wrong. This applies to cables as well in my experience.
The good news for my friend was he had no problem selling the Playback Designs. Audio  products that reach esteemed status via reviews and word of mouth sell quickly in most cases. When I sold my Metrum DAC a few years ago I received five offers within 6 hours of placing my audiogon ad. At that time it was a very hot and high in demand DAC. The Yamamoto flies under the radar in U.S.and wouldn't sell as easily on the used  market despite its excellent sound quality. 
yes , i just upgrade today , first impression is not bad, increase in the whole performance but not huge than upgrade the silver transformer, have to wait til it burn in to evaluate, my level 3 full grade with audionote trans 280 in below

Looking good Gary, looks like you upgraded to the silver power transformer and the AES to the Audio Note or did you already have the silver power transformer? It would be interesting to see how it now compares to the Metrum Pavane etc. thanks for providing your feedback as there are very few reviews/comparisons available. That said, I have placed an order for the level 3 version....

The Spring dac does not come with digital volume control and requires a preamp according to its designer. He must have very good reasons to not include a digital volume control.
Because all digital domain volume controls "bit strip" if not used at or above 75% of full volume.
EG: The lower you go the more they strip, 16bit, 14bit, 12bit resolution.
That’s why it’s best to leave them at full and use a 10kohm passive preamp, like the $49 Schiit Sys. If your poweramp is 47kohm input impedance or higher.

Cheers George
Comments from Jeff Zhu :-

".....I can’t say it’s 1 or 2 DACs inside. Physically, it is 1 DAC module, but it works in 2 different modes. Each mode uses different part of the module and also shared some parts. Spring is a 24bit DAC, bit23 is msb (most significant bit) and bit0 is lsb (least significant bit). Yes, you are right, more bits can be used for digital volume control. But Spring is a pure DAC without digital volume. Actually digital volume is no match for a good resistor attenuator. That’s why we need a dedicated pre-amp, rather than use digital volume in a DAC....."
My friend will audition the Spring DAC in his main system. It will be used with his Absolare Altius preamplifier. If I’m able to hear it in my system it will used with the Coincident Statement Line Stage. Either will most definitely reveal the innate sound character of this DAC.
Hi Charles,
That is some setup that it will be tested in! I look forward to your combined thoughts on the sonic signature of the Holo. What may I ask is it up against?

Kind regards
Hello Greg, 
I had mentioned this in an earlier post. My friend has the Bricasti SE and I have the Yamamoto YDA-01a DAC. He uses a MAC computer set up and I use the P.S.Audio PWT.
Full disclosure,
My Yamamoto DAC is modified with the Duelund CAST copper foil capacitors  (output coupling) SR Black fuse and sits on, a  Star Sound Apprentice platform.
Thanks Charles for the further info, I was not sure if the lineup had changed. Will be interesting though.