Pro-Ject Phono Box DS3 B Review

[amirm]

This is a review and detailed measurements of the Pro-Ject Phono Box DS3 B phono preamplifier. It was kindly drop shipped to me by a member and costs US $799.

I have a soft spot for white aluminum cases such as we have here in DS3B. I do wish the corners were a bit softer though as they are sharp enough to cut your hand! Nice to see so much flexibility as far as settings. Even better is a rare feature: balanced input and output:

It is a shame we don't see more balanced phono stages as their are so susceptible to ground loops due to their high gains. We even have trigger control for automation.

Not a fan of the 18 volt external switching power supply though at this price level. The low voltage is also liable to limit the headroom of DS3B.

For testing, I exclusively used XLR input and outputs.

Project Phono Box DS3 B Measurements
I started my testing using the usual dashboard and setting the gain to 40 dB:

As you see, the effective gain is 6 dB which is likely due to it not compensating for differential aspect of balanced input. I considered backing this out but at the end decided to stay with the same input voltage I test all the other phono stages. At this setting, we don't see any power supply noise or distortion. SINAD then is dominated by noise which places the DS3 B above average:

Upping the gain to "60 dB" naturally lowers SINAD due to increased noise:

Most important aspect of any phono stage is proper implementation of RIAA equalization and the DS3B nails it:

It also sports a proper sharp high pass filter if you engage subsonic filter.

We can see the effect of low rail voltages in somewhat early clipping (my target is 100 mv):

Unfortunately as frequencies increase, you lose a lot of that headroom:

Since pops and ticks by nature lots of high frequency energy, this is a liability.

Absolute distortion is quite low and much better than the format itself:

Conclusions
The Phono DS3 B nails the looks and feature set, making it a rather unique offering in phono stages. Performance generally is very good but suffers from insufficient headroom. For your clean records, that won't be a factor and you will hear very neutral tonality courtesy of excellent frequency response.

I am going to put the Project Phono Box DS3 B on my recommended list.
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[Endibol]

This is a review and detailed measurements of the Pro-Ject Phono Box DS3 B phono preamplifier. It was kindly drop shipped to me by a member and costs US $799.
View attachment 345642
I have a soft spot for white aluminum cases such as we have here in DS3B. I do wish the corners were a bit softer though as they are sharp enough to cut your hand! Nice to see so much flexibility as far as settings. Even better is a rare feature: balanced input and output:
View attachment 345643
It is a shame we don't see more balanced phono stages as their are so susceptible to ground loops due to their high gains. We even have trigger control for automation.

Not a fan of the 18 volt external switching power supply though at this price level. The low voltage is also liable to limit the headroom of DS3B.

For testing, I exclusively used XLR input and outputs.

Project Phono Box DS3 B Measurements
I started my testing using the usual dashboard and setting the gain to 40 dB:
View attachment 345644
As you see, the effective gain is 6 dB which is likely due to it not compensating for differential aspect of balanced input. I considered backing this out but at the end decided to stay with the same input voltage I test all the other phono stages. At this setting, we don't see any power supply noise or distortion. SINAD then is dominated by noise which places the DS3 B above average:
View attachment 345645

Upping the gain to "60 dB" naturally lowers SINAD due to increased noise:
View attachment 345647

Most important aspect of any phono stage is proper implementation of RIAA equalization and the DS3B nails it:
View attachment 345646
It also sports a proper sharp high pass filter if you engage subsonic filter.

We can see the effect of low rail voltages in somewhat early clipping (my target is 100 mv):
View attachment 345648

Unfortunately as frequencies increase, you lose a lot of that headroom:
View attachment 345649
Since pops and ticks by nature lots of high frequency energy, this is a liability.

Absolute distortion is quite low and much better than the format itself:
View attachment 345650

Conclusions
The Phono DS3 B nails the looks and feature set, making it a rather unique offering in phono stages. Performance generally is very good but suffers from insufficient headroom. For your clean records, that won't be a factor and you will hear very neutral tonality courtesy of excellent frequency response.

I am going to put the Project Phono Box DS3 B on my recommended list.
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thanks for this phono stage review! Happy to see one again.

 

[Videoteque73]

I imagine all those controls will surely help to adapt the cartridge to the pre.

 

[Chagall]

Amir, thank you for the review!

However, Loading pF, Loading Ohms, Subsonic, 10R, 30R,...,1k - embarrassed to say I don't understand what any of these buttons do

 

[Art of sound]

thanks for the review. given how the sales of records have boomed in recent years, phono measurements are welcome. although i don't want to put my money where my mouth is and go away from digital

 

[Koeitje]

thanks for the review. given how the sales of records have boomed in recent years, phono measurements are welcome. although i don't want to put my money where my mouth is and go away from digital

I still occasionally buy a record and I don't even have a player. Usually buy straight through the artist's own shop. I don't listen to it, but I like the artwork and supporting the artist.

 

[DSJR]

A few years back, I played with an Ifi phono stage with loading switches on it and in all honesty, I'd suggest that much of it is academic as the frequencies affected tend to be higher than most vinyl music signals which appear to be below 12kHz or so, anything above being noise with most pickups. Got to say for me personally and past experience, I'd rather look at the bass end more.

The best phono stages don't seem to emphasise ticks and splats the way others can and do and this can really help in 'suspension of disbelief' when playing records. I still blow hot and cold on the medium (emotion vs. objective), but like the 'act' of playing records still.

 

[beagleman]

I would love to see an actual measurement of a vinyl record being played, with silent grooves, Pink noise and several frequencies over many bands, and see the "Actual" noise and distortion when in use.

I would think the distortion and noise would be magnitudes higher in actual usage.

 

[AdamG]

Manufacturer Specifications:

Technical Specifications​

Input impedance:	Stepless 10 – 1000 ohms or fix 47kOhms
Input capacitance:	50, 150, 300, 400 pF
Gain (+ 6dB using XLR Out sockets):	40, 45, 50, 55, 60, 65 dB
Signal / Noise ratio MM (40dB):	104dBV, 111dBV - ‚A‘ weighted
Signal / Noise ratio MC (60dB):	85dBV, 91dBV - ‚A‘ weighted
THD at 1 kHz:	<0,001% MM, < 0,004% MC
THD (20Hz-20kHz):	<0,005% MM, < 0,01% MC
RIAA-equalization curve accuracy:	< 0,25dB / 20Hz - 20kHz
Subsonic filter:	at 20Hz with 18dB/octave
Input:	1x 5-pin mini XLR / 1x pair XLR / 1x pair RCA phono
Line-level output:	1x pair RCA, 1x pair XLR
Wiring XLR sockets:	1 ground, 2 “hot” and 3 “cold”
Trigger In/Out:	12V on/off detector
Power supply DC:	18V/500mA
Power consumption:	18V/max.290mA DC, <0.5 W standby
Dimensions:	206 x 72 x 194 (205 with sockets) mm
Weight:	1480g without power supply

 

[Zapper]

Unfortunately as frequencies increase, you lose a lot of that headroom:

Can anyone explain this characteristic in terms of possible circuit topology?

A simple phono stage consists of a single op-amp with RIAA equalization. If the rise in distortion were due to amplitude clipping in an op-amp, I would expect the opposite characteristic: as the gain decreases with frequency, the clipping threshold would rise with frequency.

This suggests to me a slew-rate limit distortion in a fixed gain amplification stage preceding the RIAA equalization, as the amplitude of onset of high distortion scales approximately with 1/f. (The maximum slew of a sine wave is proportional to amplitude times frequency).

 

[peniku8]

That's a very nice looking device and I love the fact that it sports balanced connections (praying unbalanced will die out some day), but the "Subsonic" button label is embarrassing. "Subsonic" is a speed, the word here is "Infrasonic".

 

[Zapper]

We can see the effect of low rail voltages in somewhat early clipping (my target is 100 mv):

Unfortunately as frequencies increase, you lose a lot of that headroom:

Since pops and ticks by nature lots of high frequency energy, this is a liability.

Has anyone shown that high fidelity reproduction of pops and clicks, with all their high frequency energy, is audibly superior to clipping them at a lower amplitude? Passing a 100mV click @ 40dB gain is a 10V output from the pre-amp - that's going to be bloody loud if the power amp can pass it along unclipped to the speakers. 26dB louder than the recorded material at 5mV level. And there is a good chance of clipping in the power amp instead, depending on the listening level.

It's not a-priori obvious to me that a click of that magnitude wouldn't sound better if clipped to a lower amplitude, say 5V.

 

[dzerig]

I don't see how this gets the same rating as the Mani 2. So far as I can see, we have higher headroom at 45, pretty close at 60, higher headroom at all frequencies, lower sinad by a hair overall. Yet, this is $799 vs $149 for which you get some useful features, for some people. But 90% won't care about balanced and will set and forget the settings so the bottom facing adjustments aren't as big an issue either )).

 

[dzerig]

That's a very nice looking device and I love the fact that it sports balanced connections (praying unbalanced will die out some day), but the "Subsonic" button label is embarrassing. "Subsonic" is a speed, the word here is "Infrasonic".

lesshearable

 

[beagleman]

That's a very nice looking device and I love the fact that it sports balanced connections (praying unbalanced will die out some day), but the "Subsonic" button label is embarrassing. "Subsonic" is a speed, the word here is "Infrasonic".

Technically you are right of course, but I have seen "Subsonic" used by most companies, and in fact, I just googled it and found many dozen examples of it being used as an alternate name for what it technically "Infrasonic" almost interchangeably. It seems most companies are using subsonic instead of "Infrasonic", but intentionally.

 

[Thomas_A]

I don't see how this gets the same rating as the Mani 2. So far as I can see, we have higher headroom at 45, pretty close at 60, higher headroom at all frequencies, lower sinad by a hair overall. Yet, this is $799 vs $149 for which you get some useful features, for some people. But 90% won't care about balanced and will set and forget the settings so the bottom facing adjustments aren't as big an issue either )).

Both subsonic filters, gain and loading options are important features that most phono preamps lack. I bought the Muffsy preamp just because of the very flexible loading options for MM.

 

[Prana Ferox]

I'd argue that buying a dedicated phono preamp and especially one at this price point, adjustments for cartridge loading compensation should be mandatory.

On the other hand that looks like the same universal wallwart power brick I get with random AliExpress purchases.

Also, I don't see a ground lug? Is it the top left screw on the back with just no label or symbol? I do think the labeling on this thing is a little too clever for its own good.

 

[Anthony101]

Thank you, for reviewing and recommending the Project Phono Box DS3 B. Let's hope that the Project and other audio manufacturers consider designing balanced phono stages in the future.

 

[levimax]

I would love to see an actual measurement of a vinyl record being played, with silent grooves, Pink noise and several frequencies over many bands, and see the "Actual" noise and distortion when in use.

I would think the distortion and noise would be magnitudes higher in actual usage.

There is a test script created by one of our members for testing carts. You can get a very good idea of exactly what LP's limitations are by viewing the script results. If you read the thread you will also see that test records are a very big issue and pink noise is not really a viable option. While noise and distortion certainly are orders of magnitude higher than digital if you look at the results of the the "good carts" and "weight" them for where people can hear well and not so well this give a strong clue as to why LP's sound as good as they do. LP's do their best where people hear the best and their worst where people can't hear very well.

Phono Cartridge Response Measurement Script

This thread is intended to consolidate the technical discussion and further development of Scott Wurcer's frequency response measurement script to a central area. I'd like to keep this discussion about the tool rather than specific cartridges. I'll edit this and the subsequent reserved posts in...

www.audiosciencereview.com

 

[Ted G]

I don't see how this gets the same rating as the Mani 2. So far as I can see, we have higher headroom at 45, pretty close at 60, higher headroom at all frequencies, lower sinad by a hair overall. Yet, this is $799 vs $149 for which you get some useful features, for some people. But 90% won't care about balanced and will set and forget the settings so the bottom facing adjustments aren't as big an issue either )).

I don’t get it, $800 for a phono stage! Is it really that much better? The reason I gravitated to this site is because they call this stuff out.