• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Review and Measurements of Holo Audio May --- Probably the best discrete R2R DAC

WolfX-700

Active Member
Patreon Donor
Joined
Jul 26, 2019
Messages
156
Likes
1,094
Location
China
#1
After I released the measurements of the Holo Audio Spring DAC, something interesting happened.

The reason was because I was wrong about the version --- I measured Spring Lv2 instead of what I thought and declared Spring 2 Lv2.When the developer found me and told me this mistake. I was surprised that Spring could have excellent measurements.And tell him: I am curious how good the measurement results of Spring 2 will be?

The developer told me very lightly: Spring2's measurement is indeed better, but you should measure my new product: May

So on this kind of cold rainy day. I received this product.

This is a commemorative prototype, and the color scheme of the shell is said to be slightly different from the official release. But the developers assured me that the quality is the same as the retail version. I also asked the developer for the price. This is an expensive product with a price of about 4000USD +
It's a split model, which means that the power box (lower) and DAC (upper) are separated. I'm talking to the developer about opening these cases to get some internal photos.

Photo.jpg



Ah how shameless—These mundane developers explain the ways in which discrete R2R measurements are bad.

They say that discrete R2R cannot be measured with measurements, yes,

But it was actually themselves, in their reckless way.

Compound their pains beyond their proper share.


Ok now this is the measurement result

Dashboard:
Dashboard.jpg


D-R:
DR.jpg



THD+N-Ratio-Freq.jpg

Linearity-(-20.jpg



SMPTE-Ratio.jpg


Multitone.jpg


Filters:
Filters.jpg



J-Test:
J-Test-PLL-On-vs-Off.jpg



One more thing:

The developer told me that May's PLL is very powerful

So I did the following measurements:

I added 1KHZ sine wave jitter from 10ps to 1.5us And measure 1KHZ THD+N.Jitter without PLL will directly affect the harmonics of 2KHZ


I was surprised to see the results that were almost immune to Jitter!

THD+N-Ratio-VS-Jitter.jpg



How about J-Test?

I added 1us 1KHZ sine wave jitter(the green one) .

J-Test-PLL-On-vs-Off-R-.jpg


J-Test-PLL-On-vs-Off-B.jpg


J-Test-PLL-On-vs-Off-G.jpg


It's AWESOME!

After the PLL eliminated jitter, not only did we not see a significant increase in side lobes, even the main lobe width did not increase!


Here's what I told the developers after measuring:
“It is my pleasure to be able to measure such products, not only because of the measurement results, but also because of the effort behind these results. I always think that it is good to make a chip DAC into a chip data sheet level, but it is worthy of making products beyond the data sheet.
May is a product I consider respectable.”
 
Last edited:

pos

Senior Member
Patreon Donor
Joined
Feb 13, 2018
Messages
372
Likes
365
#2
Nice measurements once again @WolfX-700, thank you!

I am curious about this DAC: why is there two different units? Is the lower one the power supply?
I am also curious about the PLL as it looks like recent DAC design tend to favor using an ASRC, or a FIFO for the most exotic designs.
 

solderdude

Major Contributor
Joined
Jul 21, 2018
Messages
3,375
Likes
5,953
Location
The Neverlands
#3
Nice, Can you show filters ?

Both in R2R and DS there are abominations and excellent implementations.
For $4k it should be possible to design a good measuring R2R but there are other even more expensive ones that 'f it up enormously.
 

WolfX-700

Active Member
Patreon Donor
Joined
Jul 26, 2019
Messages
156
Likes
1,094
Location
China
#4
Nice measurements once again @WolfX-700, thank you!

I am curious about this DAC: why is there two different units? Is the lower one the power supply?
I am also curious about the PLL as it looks like recent DAC design tend to favor using an ASRC, or a FIFO for the most exotic designs.

Yes

It's a split model, which means that the power box (lower) and DAC (upper) are separated.
 

pkane

Addicted to Fun and Learning
Patreon Donor
Joined
Aug 18, 2017
Messages
896
Likes
1,234
Location
North-East US
#5
After I released the measurements of the Holo Audio Spring DAC, something interesting happened.

The reason was because I was wrong about the version --- I measured Spring Lv2 instead of what I thought and declared Spring 2 Lv2.When the developer found me and told me this mistake. I was surprised that Spring could have excellent measurements.And tell him: I am curious how good the measurement results of Spring 2 will be?

The developer told me very lightly: Spring2's measurement is indeed better, but you should measure my new product: May

So on this kind of cold rainy day. I received this product.

This is a commemorative prototype, and the color scheme of the shell is said to be slightly different from the official release. But the developers assured me that the quality is the same as the retail version. I also asked the developer for the price. This is an expensive product with a price of about 4000USD +
It's a split model, which means that the power box (lower) and DAC (upper) are separated. I'm talking to the developer about opening these cases to get some internal photos.

View attachment 40835


Ah how shameless—These mundane developers explain the ways in which discrete R2R measurements are bad.

They say that discrete R2R cannot be measured with measurements, yes,

But it was actually themselves, in their reckless way.

Compound their pains beyond their proper share.


Ok now this is the measurement result

Dashboard:
View attachment 40837


View attachment 40838
View attachment 40839


View attachment 40840

View attachment 40841



J-Test:
View attachment 40842


One more thing:

The developer told me that May's PLL is very powerful

So I did the following measurements:

I added 1KHZ sine wave jitter from 10ps to 1.5us And measure 1KHZ THD+N.Jitter without PLL will directly affect the harmonics of 2KHZ


I was surprised to see the results that were almost immune to Jitter!

View attachment 40845



How about J-Test?

I added 1us 1KHZ sine wave jitter(the green one) .

View attachment 40846

View attachment 40847

View attachment 40848

It's AWESOME!

After the PLL eliminated jitter, not only did we not see a significant increase in side lobes, even the main lobe width did not increase!


Here's what I told the developers after measuring:
“It is my pleasure to be able to measure such products, not only because of the measurement results, but also because of the effort behind these results. I always think that it is good to make a chip DAC into a chip data sheet level, but it is worthy of making products beyond the data sheet.
May is a product I consider respectable.”
Very pretty measurements! :) Probably the best-measuring R2R DAC I've seen. Is this available for sale yet?
 

WolfX-700

Active Member
Patreon Donor
Joined
Jul 26, 2019
Messages
156
Likes
1,094
Location
China
#6
Nice, Can you show filters ?

Both in R2R and DS there are abominations and excellent implementations.
For $4k it should be possible to design a good measuring R2R but there are other even more expensive ones that 'f it up enormously.
Filters.jpg
 

VintageFlanker

Major Contributor
Patreon Donor
Joined
Sep 20, 2018
Messages
1,008
Likes
1,677
Location
Paris
#7
Very pretty measurements! :) Probably the best-measuring R2R DAC I've seen.
For sure. Still the IMD which is a bit... meh. But overall exceptional performance "for R2R".

Can't find the price of this, but I guess the value won't be that good.:D
 

WolfX-700

Active Member
Patreon Donor
Joined
Jul 26, 2019
Messages
156
Likes
1,094
Location
China
#8
Very pretty measurements! :) Probably the best-measuring R2R DAC I've seen. Is this available for sale yet?
The developer said it will be on sale soon, I think it will be later this year (coming soon, isn't it?)
 

Matias

Senior Member
Patreon Donor
Joined
Jan 1, 2019
Messages
312
Likes
307
Location
São Paulo - Brazil
#11
Excellent! Now only if you could reach out and get a Denafrips Terminator to measure it would be awesome.
 

JohnYang1997

Major Contributor
Joined
Dec 28, 2018
Messages
1,786
Likes
1,173
Location
Sydney - Australia
#12
THD VS AMPLITUDE? R2R architecture has its limitations even when corrected by fpga(i suppose that how he does it). The DNL of r2r should be pretty bad and it's shown here in the imd vs amplitude. I'm wondering does thd show the same behavior.
 

WolfX-700

Active Member
Patreon Donor
Joined
Jul 26, 2019
Messages
156
Likes
1,094
Location
China
#13
THD VS AMPLITUDE? R2R architecture has its limitations even when corrected by fpga(i suppose that how he does it). The DNL of r2r should be pretty bad and it's shown here in the imd vs amplitude. I'm wondering does thd show the same behavior.
I think the measurement of linearity is clear enough
 

JohnYang1997

Major Contributor
Joined
Dec 28, 2018
Messages
1,786
Likes
1,173
Location
Sydney - Australia
#14
Also it's better to show multitone with down sloping spectrum(pink for example) and NID(No Interharmonic Distortion). Also at different amplitude and/or with different numbers of sines.
 
Top Bottom