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Project Pre Box S2 DAC & Headphone Amp Review

luisma

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Yes, I am new to this site and I think I saw his analysis after I ordered it. It cost about $80 from China. Their LPA costs $250. I will probably sell it and buy a Topping D90 with the 4499 chip. I want to compare them after I buy the D90.
The S2 cost $80 from China?
 

luisma

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No, the Linear Power Supply costs $80
I tried those, IIRC the power was listed as 25 W on 5V but when arrived it could not power the S2 alone (which takes 0.4 amps on full use measured by my digital voltmeter) it failed and honestly they were very friendly accepting the return but I could not even use it
This is the exact description of the item I purchased (1.5 yrs ago)
LHY LPS Linear Power Supply USB 5V + DC 5V output 25W TALEMA Low Noise PSU
Here you can see the DAC connected but not powering up
Test thoroughly when you receive the item
It is not the chinese products are meant to be deceiving but the QC is not always good and that is why these things fail
On the other hand your seller and product might be different and better, I'm just posting my experience as a friendly warning on what you could expect



DEVICE-CONNECTED-TO-LPS-FRONT.jpg
 

slingshot

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This is what I am buying. Someone on a forum recommended it with the S2

DAC-X6 30AV DC12V/2.5A+USB 5V/5A DC dual output linear thermal power supply voltage regulator DAC XMOS Mobile phone power supply
 

luisma

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I would love to test the Toppings products, haven't tried them yet
 

luisma

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This is what I am buying. Someone on a forum recommended it with the S2

DAC-X6 30AV DC12V/2.5A+USB 5V/5A DC dual output linear thermal power supply voltage regulator DAC XMOS Mobile phone power supply
The LPS subject YMMV, measurements by Amir shown there is no difference (at least with some tested), I have found myself (and some people I had over on blind listening) that perceived sonics are more pleasant but there are so many variables to consider and so strict and rigurous the AB testing that I can't really tell it makes an improvement objectively speaking because my former testing wasn't controlled. I will be doing some listening back to my S2 which was just returned (loaned to a friend) and will post back here if interested. I really want to find out that it makes no difference at all to put this subject to rest.
 

luisma

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Indeed. Imagine what a good deal the single-ended E1DA 9038d will be.. :)
the 9038D It will be but you are comparing different products, you can feed this DAC to a preamp or integrated, you can't do that with the 9038D, for exclusive headphone use the 9038D will be better, I have the PDv2 and my 9038D will be on the way when it gets released
 

luisma

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Somehow I recall contract manufacturer was in China. No?
It could have been initially, there was an issue with "pink capacitors" blowing caps, then there was a recall and released the current version with better capacitors. Also when powering through the micro b usb connector some people found the connector "fell" and got loose inside the DAC. I am very careful when plugging something there just in case.
 

Jhify

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I have read a bit more about this unit and seen more comprehensive mesurements (using it as an amp) on antoher website. It seems like the 2nd harmonic distortion spike rises above elses when you pass above -10db and get worst the more you get near full output ruining the sinad result at max volume. Those mesurements show that best sinad is reached below -10db and is about 110+db which would be more or less the 0.0003% claimed by the manufacturer ? So using it only as a DAC into a preamp it would be logical to set the volume about -12 / -10 db for the best results am I right ? If someone more aware than me have an answer I'd be pleased to read it. Just curious.

On another hand, I also wonder is the slight harhness in the highs I have heard with the topping d50 comparing the two units in preamp mode could be the ESS IMD hump. Could it be it ? I might do more comparison to figure this out.
 

luisma

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It seems like the 2nd harmonic distortion spike rises above elses when you pass above -10db and get worst the more you get near full output ruining the sinad result at max volume. Those mesurements show that best sinad is reached below -10db and is about 110+db which would be more or less the 0.0003% claimed by the manufacturer ? So using it only as a DAC into a preamp it would be logical to set the volume about -12 / -10 db for the best results am I right ?
I think you stated a perfectly valid point here, using it with an analog preamp it would be better to keep it low (possibly even less than neg 10), completely correct thank you
 

Jhify

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I think you stated a perfectly valid point here, using it with an analog preamp it would be better to keep it low (possibly even less than neg 10), completely correct thank you

I really wonder why though. No other ess9038 design seems to have this issue. Could it be the low wattage/voltage input ? The enginners might have had some restrains with the USB powered feature which was challenging perhaps
 

SolarFox

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Hello,
I`m new on this forum but i`m reading posts here for a long time.
I own this S2 DAC for a year and not planing to buy new one soon and will tell you my personal opinion or better, also my friends opinion, because this DAC was moving to many systems recently and no one for now tell that this is bad DAC. Of course, we did not use DAC on USB Power only because we have spare Power Bank and with that it was already improvement in sound quality, puncher and tighten bass, wider stage, more natural sound etc. But than some ppl say Power bank is not good for Hi-Fi than i think, why not order a Linear power supply. I Ordered S12 Ultra Low noise Linear supply from Aliexpress with audio grade capacitors and R Core (D TYPE) transformer and some alu box. I assembly that and use S2 DAC that way.

Now sound got huge step forward in sound quality. For example: you listening something and disconnect external power supply, sound quality drop instantly and jump back instantly when u put it back, it`s like you listening another much expensive device which have huge sound stage, excellent details in full spectrum and background silence which is rare etc.

Headphones:
My headphones are only 32 ohm with some replaced drivers from aliexpress and drivers sound amazing believe or not :) so i have no problem with that. We try AKG also and some others, there is no problem driving them with attached Linear power supply attached to S2.

PC audio:
I use ONLY USB on S2 and and most tracks are 24 bit or DSD for listening, now to fix PC timing problems, Kernel timer resolution optimization etc, you need another software to fix that, (I don`t want to do sponsor them and get kick from forum, google it) with that you got more upgrade in sound quality comming out from S2. Now you got sound which is NO more analytical that can usual coming out from PC audio and you can enjoy your S2 with full potential. I also prefer WASAPI exclusive mode out instead of ASIO, sound with WASAPI mode, sounds little little more natural.

S2 direct on Mono block pre-amplifiers:
We try S2 on a huge Karan Acoustics mono block Amplifiers (2x 2000W sinus on 8 ohm, don`t ask for price :)) and S2 can drive them more then enough for even loud listening and we still have 30% of volume left.

Distortoin Compensate On or OFF? Well, default is OFF, but with ON you again gain a little in sound quality.

Filters OFF, except for DSD-s you need to use some because DSD-s should be listened with some filters, usual fast minimum filter )if i remember good) do good job but that depend on your choice. also remember that only PCM 358 Khz can compare with DSD in sound quality.
16 Bit 44.1 Khz (CD Quality) can`t match even to 24 bit 44.1 Khz so don`t be fooled that CD can sound better than 24 bit PCM or DSD. It simply can`t or you have same album which is badly mastered in 24 bit or your CD player is much better than your DAC.

If you plan to buy S2 DAC so you can enjoy MQA, DSD, PCM listening, don`t forget to buy Linear power supply, you won`t regret.

p.s. sorry for bad english.
 
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Robin L

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The Toneaudio overall Product of the year is this squeaky little Pro-ject box. Go Figure.

This is a link to their PDF. No pagination, a little shy of 2/3s the way through, start of the product of the year awards [which come after the "Exceptional Value" awards, which naturally kicks off with a pair of Bryston Monoblocks for around $23,990.00].

http://www.tonepublications.com/MAGPDF/TA_100.pdf
 

eXlero

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got a really bad unit yesterday from my local retailer. brought it in, confirmed that it was bad (sometimes didn't get past the initial screen with the "Pro-Ject" text, but most of the times the volume knob did not do anything at all; pc would see it connected via usb, but there was no sound coming out of it either) and exchanged it with a working one.
well, "working" with the known issues related to MQA stutter on Tidal.
otherwise, I kinda like it.
 
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Jhify

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got a really bad unit yesterday from my local retailer. brought it in, confirmed that it was bad (sometimes didn't get past the initial screen with the "Pro-Ject" text, but most of the times the volume knob did not do anything at all; pc would see it connected via usb, but there was no sound coming out of it either) and exchanged it with a working one.
well, "working" with the known issues related to MQA stutter on Tidal.
otherwise, I kinda like it.

Hey, I just listened to a whole album with MQA passthrough activated on tidal and I didn't have any dropout. Since the recent updates from tidal the issue seems to be fixed. Did you install the windows driver ? And deactivated the loundness normalization which is on by default when you launch tidal ? If it still doesnt work you can untick MQA passthrough and let tidal do the first unfold as well that will solve the hiccup and there's no difference soundwise. There's still an issue when you get back from MQA to PCM with optimal transitent filter selected (loudness is reduced by few db) but just pick any other filter the difference is hardly audible or none. Enjoy it, it's a great sounding unit :) I just whish I could dim the screen.
 

eXlero

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Hey, I just listened to a whole album with MQA passthrough activated on tidal and I didn't have any dropout. Since the recent updates from tidal the issue seems to be fixed. Did you install the windows driver ? And deactivated the loundness normalization which is on by default when you launch tidal ? If it still doesnt work you can untick MQA passthrough and let tidal do the first unfold as well that will solve the hiccup and there's no difference soundwise. There's still an issue when you get back from MQA to PCM with optimal transitent filter selected (loudness is reduced by few db) but just pick any other filter the difference is hardly audible or none. Enjoy it, it's a great sounding unit :) I just whish I could dim the screen.

thanks for the info. got the same settings in my setup. drop-outs are indeed less and less lately (in MQA, not MQB).

but I have another question: what would be the optimal volume setting when using the Pre Box S2 Digital as a DAC/Preamp (in my case feeding the THX 789)? Maxed out volume at 0dB? Or something lower? (I think I read somewhere saying that around -12/-10dB would be best in such a setup)
 

Jhify

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thanks for the info. got the same settings in my setup. drop-outs are indeed less and less lately (in MQA, not MQB).

but I have another question: what would be the optimal volume setting when using the Pre Box S2 Digital as a DAC/Preamp (in my case feeding the THX 789)? Maxed out volume at 0dB? Or something lower? (I think I read somewhere saying that around -12/-10dB would be best in such a setup)

According to ASR mesurements it says distorsion takes over at -14db so the greatest sinad would be achieved at -14db I guess. And when it says distorsion takes over, this 2nd harmonic odd rise is to blame.
But take this with a grain of salt. It's one unit mesured by one person with its context. I have seen other mesurments of the amp section that shows the 2nd harmonic is rising above -120 db only with a non resistive load and near full out put which is nowhere near real world situation.
However, harmonic distorsion is less likely to be audible rather than intermodulation distorsion or noise and probably way under earing threshold even at full output with the PSB2.
I'd say don't worry to much a it. I'd pick anything maybe under -5db that's handy with your amp and headphone and enjoy the music :)
 

Jhify

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thanks for the info. got the same settings in my setup. drop-outs are indeed less and less lately (in MQA, not MQB).

but I have another question: what would be the optimal volume setting when using the Pre Box S2 Digital as a DAC/Preamp (in my case feeding the THX 789)? Maxed out volume at 0dB? Or something lower? (I think I read somewhere saying that around -12/-10dB would be best in such a setup)

I just noticed the matrix audio DAC in your setup. Is there any audible difference with the PBS2 ? Since the release of software MQA decoding I feel like there isn't much need of a MQA certified DAC anymore as the vast majority of tidal masters only have one unfold to be decoded. Hardware decoding is only required for the following unfolds which are rare and most likely result in inaudible differences compared to the first one. If you like the matrix audio better maybe use this one instead and use the PSB2 for travel or other purposes. I have settled mine on my bedside table :)
 

eXlero

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I just noticed the matrix audio DAC in your setup. Is there any audible difference with the PBS2 ? Since the release of software MQA decoding I feel like there isn't much need of a MQA certified DAC anymore as the vast majority of tidal masters only have one unfold to be decoded. Hardware decoding is only required for the following unfolds which are rare and most likely result in inaudible differences compared to the first one. If you like the matrix audio better maybe use this one instead and use the PSB2 for travel or other purposes. I have settled mine on my bedside table :)

can't say I hear a big difference in sound, but where I do (it could be just my perception, though) it is with the MQA content from Tidal.
anyway, I'm selling the Matrix Audio DAC, and the PBS2D is just here to ease the transition to the coming Topping D90 (with MQA).
 
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