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Measurements & Preview of Holo Audio Spring 3 DAC / wPreamp (Prototype)

WolfX-700

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Holo Audio's Spring series has not been updated for 3 years... Recently, even on ASR, there are rumors that Spring 3 will be released soon. Last year, Jeff stated in his QQ team that he would use May's module to develop Spring 3. It can be inferred that since May is ready, Spring 3 should be taken for granted... But... the release time has been delayed repeatedly.In my opinion, Jeff is waiting for his APx555B to be delivered. So less than a month after the 555 was delivered, Jeff sent me this Spring 3 prototype:
Photo.jpg

Rear.jpg


I won’t talk about Holo’s classic chassis style... The most exciting thing is the interior (it would be nice if there is a transparent version). Take a look at the photos:

ASRTD.jpg

ASRTD2.jpg


The measurement:
4VDashboard.jpg


This... feels like Jeff is trying too hard? Almost the same as May? And...we also saw a bunch of relays in the photo above? Because it is equipped with (analog) pre-amplifier...
FullDashboard.jpg

MAX output 11.86VRMS
Dynamic-Range---NoWt.jpg

Linearity-(-20.jpg

Multitone.jpg

RMS-Level.jpg


Let’s take a look at (I think) Jeff’s biggest progress in R&D after receiving 555:
12K-2.jpg

12K.jpg
 
Wow, this is really impressive!!!
 
Analog pre-amp meaning analog volume control?
 
Color me impressed! I love to see the technical progress achieved by solid engineering and extensive testing, together with such attention to detail at a very reasonable price point: nice!!

We do live in a golden age for audio electronics, and transducers are getting there!
 
Holy heck, that jitter performance is superlative. I'm guessing these measurements were taken in NOS mode?
 
Could you do an IMD measurement for this DAC? I'm guessing it is similar to the other Holo Audio DACs but it would be nice to confirm that.
 
Hi WolfX,

Couple of issues you noticed in Spring2 measurement and I would like to know if those are addressed.
1. Inconsistent channel performance (from your data, Spring3 seems good).
2. Worse performance for low sample rate (48k vs 96k).
3. Oversample mode performs worse than NOS.
4. Lower output level --> it is good now.

I am currently own Spring2 Level2 and quite enjoy it, can't wait to see the final Spring3 out~

William
 
Any idea if the optional pre amp module can be incorporated into the May?
 
These measurements are for the KTE version with the same titanis USB board as May?. Or it's a Spring 3 level 2?.
 
Looks like this is available to order. Are we going to see a full review now? Also, which level/version was the unit in this preview?
 
Looks like this is available to order. Are we going to see a full review now? Also, which level/version was the unit in this preview?

Well Wolf already reviewed it completely, no? I believe so far the trend was that these review units were "Level 2" straight from the factory, in this case with the added pre-amp module.

The Level 3 / KTE thing is there for people who believe in silver, direct soldering, and hand-wound things to make a difference. Wolf himself purchased a Spring 2 Level 2 for himself so I think that shows what the most logical choice would be :p
 
Well Wolf already reviewed it completely, no?
Did he? It clearly says prototype in the thread title. Wouldn't it be nice to verify if anything has changed from the prototype to production unit?

The Level 3 / KTE thing is there for people who believe in silver, direct soldering, and hand-wound things to make a difference.
What about the "Enhanced USB Module w/ Titanis 2.0 circuit" that is also included in the KTE version? How that performs over the level 1/2 versions would be of interest to me (and probably others too).

Wolf himself purchased a Spring 2 Level 2 for himself so I think that shows what the most logical choice would be
Well this is the Spring 3 and it would be nice to know (without having to guess) which version was tested mainly because of the enhanced USB module in the KTE.
 
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What about the "Enhanced USB Module w/ Titanis 2.0 circuit" that is also included in the KTE version? How that performs over the level 1/2 versions would be of interest to me (and probably others too).

On the top it says the USB module from May is included in Spring 3. Then on the bottom it says only KTE has the Titanis thing. To me this feels like a shameless lie or at the least intentional misconception to push people to KTE. But who knows....
 
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