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Pro-ject Phono Box MM Review

Rate this phono stage:

  • 1. Poor (headless panther)

    Votes: 32 24.1%
  • 2. Not terrible (postman panther)

    Votes: 81 60.9%
  • 3. Fine (happy panther)

    Votes: 16 12.0%
  • 4. Great (golfing panther)

    Votes: 4 3.0%

  • Total voters
    133

amirm

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This is a review and detailed measurements of the Pro-Ject Phono Box MM preamplifier. It is on kind loan from a member and costs US $89.
Project Phono  Box MM stage preamplifier review.jpg

As you see, this is a compact and sturdy box. I wonder if they put some weight in it because if feels heavy for its size. This is useful to keep it from walking although my RCA cables did pull it down.

Pro-Ject Phono Box MM Measurement
Let's start with our usual dashboard of 5 mv at 1 kHz:

Project Phono  Box MM stage preamplifier measurement.png

I like to see this measurement being noise dominated due to RIAA equalization. Here though, we have a tall third harmonic setting the limit. Still, what is there lands the unit in the middle of the pack which isn't bad:
best phono stage review 2023.png


Most important measurement here is RIAA equalization in the form of frequency response:
Project Phono  Box MM stage preamplifier frequency response measurement.png

That's extremely good! We don't see many phono stages regardless of price with such accuracy. Do note that it is flat down to below 10 Hz so any rumble, etc. will be amplified as well.

Distortion raises its ugly head early though:
Project Phono  Box MM stage preamplifier THD vs Level measurement.png

And also clips rather early. That is 1 kHz. It gets much worse at higher frequencies:
Project Phono  Box MM stage preamplifier THD vs Frequency vs Level measurement.png


I don't think I have ever tested a phono stage with so little high frequency headroom!

Excluding noise, pure distortion takes a dip where it matters (i.e. our hearing is most sensitive):
Project Phono  Box MM stage preamplifier THD pure vs Level measurement.png



Conclusions
I like the form factor of the unit at this price point. And the perfect RIAA equalization so tonality should be what the cartridge produces. Distortion though is a bit high and sets in early. Worst aspect is lack of headroom so pops and ticks will be more pronounced.

I am torn between the good and bad parts. Usually an audio device is mostly one or the other. Here we are right in the middle. I guess if you don't care about headroom, then it is a very good bargain phono stage. Personally I would look elsewhere.

---------
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/
 

renaudrenaud

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Tried the version with spdif output and it was an horror. Was able to read on ASR the confirmation of my feeling. Not sure this brand produce good products, it's more than inexpensive gadget.
 

antcollinet

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I've been waiting for this a couple of years: I is the one I bought (price driven) about 8 years ago.

I would really like to reduce pops/clicks. How much of an improvement could I expect with a pre-amp with more headroom? Will it be very noticeable?
 

MaxwellsEq

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I would really like to reduce pops/clicks. How much of an improvement could I expect with a pre-amp with more headroom? Will it be very noticeable?
In my experience, phono preamplifiers with good headroom do subjectively reduce your attention to the pops and clicks. I think it seems to make them less annoying, they seem quieter, but also seem to take up less time. This may be due to instability in the amplifier with limited headroom and it taking time to recover.
 

morillon

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This is a review and detailed measurements of the Pro-Ject Phono Box MM preamplifier. It is on kind loan from a member and costs US $89.
View attachment 297927
As you see, this is a compact and sturdy box. I wonder if they put some weight in it because if feels heavy for its size. This is useful to keep it from walking although my RCA cables did pull it down.

Pro-Ject Phono Box MM Measurement
Let's start with our usual dashboard of 5 mv at 1 kHz:

View attachment 297928
I like to see this measurement being noise dominated due to RIAA equalization. Here though, we have a tall third harmonic setting the limit. Still, what is there lands the unit in the middle of the pack which isn't bad:
View attachment 297929

Most important measurement here is RIAA equalization in the form of frequency response:
View attachment 297931
That's extremely good! We don't see many phono stages regardless of price with such accuracy. Do note that it is flat down to below 10 Hz so any rumble, etc. will be amplified as well.

Distortion raises its ugly head early though:
View attachment 297932
And also clips rather early. That is 1 kHz. It gets much worse at higher frequencies:
View attachment 297933

I don't think I have ever tested a phono stage with so little high frequency headroom!

Excluding noise, pure distortion takes a dip where it matters (i.e. our hearing is most sensitive):
View attachment 297934


Conclusions
I like the form factor of the unit at this price point. And the perfect RIAA equalization so tonality should be what the cartridge produces. Distortion though is a bit high and sets in early. Worst aspect is lack of headroom so pops and ticks will be more pronounced.

I am torn between the good and bad parts. Usually an audio device is mostly one or the other. Here we are right in the middle. I guess if you don't care about headroom, then it is a very good bargain phono stage. Personally I would look elsewhere.

---------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much
not just being part of the "all they have to do is make a serious supply etc"
carrying out tests on battery or ultralow noise supply to make sense of things, in particular on "modest" devices, will be very informative...
will offer many perspectives...

the case of prephono is really very special...
;-)
 

Verig

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Not really worth it unless on really tight budget. Cheap preamps are usually paired with cheap turntables and needles so rumble and early clipping are not good. I've listened to it, not bad really, I mean it works. But price/performance is meh.
Something like iFi Zen Phono (not Air) does much better for a bit more. iFi is also built as PSU independent and can't be improved by battery (I tried). There are no PSU related problems to begin with so well done. Most products that need better PSU are just built that way on purpose. The actual working product costs $700 but it's divided into $400 and $300 boxes.
 

Verig

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I've been waiting for this a couple of years: I is the one I bought (price driven) about 8 years ago.

I would really like to reduce pops/clicks. How much of an improvement could I expect with a pre-amp with more headroom? Will it be very noticeable?
Best way to reduce pops and clicks is to take care of your vinyls. But to answer your question: it will subjectively help, makes things much nicer. If you have a good store near by just ask for a home test. There definitely are better sounding units available.
 

morillon

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"tried" with this ifi...
i believe you but..
mesureaments?
;-)
 

Verig

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"tried" with this ifi...
i believe you but..
mesureaments?
;-)
I could not tell a difference even if I wanted to. Ifi is built surprisingly well for the price point, very very quiet, one the best regardless of price. And I've tried Ear/Yoshino tier stuff.
But sadly no measurements for you. I'd be interested in them too actually. Usually it is other way around that people claim to hear something but it would be interesting to see that there is a difference but why it's not audible.
 

Verig

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"tried" with this ifi...
i believe you but..
mesureaments?
;-)
I guess most difference comes from that iFi is 5V unit (you can use usb-barrel adapter if you wish). Many riaa's are 18-24V.

"Unusually, the ZEN Phono has its own high-tech clean power supply. It creates a 1.2MHz power supply (20,000x mains frequency of 60Hz). In this circuit, a 10uF filtering capacitor = 200,000uF at lower, audible frequencies. With serious levels of noise filtration, it performs at the level of well-designed LC filtering circuits as found in classic tube amplifiers. Further, located on its own ‘island’ PCB, it is isolated so there is no noise pollution of the analogue stage.

Just super clean +/- 12V DC.

Measured EIN (Equivalent Input Noise) is -151dBV. It is 20dBV quieter than some Stereophile Class A+ phonos which are -131dBV."

Yeah, this is the marketing, I know. But the PSU really is quite a bit different than normally so I have no problem (in technical sense) not hearing a difference with different quality power inputs.

It has balanced output too if you need a bit more. Haven't tried that.
 

JeremyFife

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JeremyFife

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Interesting review. Seems to me that Pro-ject nail the RIAA eq but neglect other aspects of the implementation... I'm sure I've seen this before with other pieces (memory fails)
 

Nippithon

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It was fun and instructive comparing Amir's so-so objective measurements to my excellent listening experience with the Phono Box. Since I heard no noise with this preamp, I expected the THD+N to be even better (I don't know how to listen for THD). My turntable doesn't need a sub rolloff and my LPs are in excellent condition so I didn't notice the lack of pop & click headroom. (Still I threw it over for something prettier.)
 

computer-audiophile

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Is the clipping level really a problem? You might want to choose a pickup that doesn't have too high an output voltage.

(But I prefer to use phono preamps with tubes anyway).
 

morillon

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Isn't the saturation level vs frequency following the RIAA correction curve here ?.
a battery of additional measures against riaa correction would certainly be welcome.. see on battery to complete..
(for every prephono)
provided the power supply is more constant, the "rankings" will be more interesting..

""in addition""
:oops:
 
Last edited:

wwenze

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I guess most difference comes from that iFi is 5V unit (you can use usb-barrel adapter if you wish). Many riaa's are 18-24V.

"Unusually, the ZEN Phono has its own high-tech clean power supply. It creates a 1.2MHz power supply (20,000x mains frequency of 60Hz). In this circuit, a 10uF filtering capacitor = 200,000uF at lower, audible frequencies. With serious levels of noise filtration, it performs at the level of well-designed LC filtering circuits as found in classic tube amplifiers. Further, located on its own ‘island’ PCB, it is isolated so there is no noise pollution of the analogue stage.

Just super clean +/- 12V DC.

Measured EIN (Equivalent Input Noise) is -151dBV. It is 20dBV quieter than some Stereophile Class A+ phonos which are -131dBV."

Yeah, this is the marketing, I know. But the PSU really is quite a bit different than normally so I have no problem (in technical sense) not hearing a difference with different quality power inputs.

It has balanced output too if you need a bit more. Haven't tried that.

Wow this is how you convert an often-feared SMPS into a piece of audiophile technology.
 

Verig

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Wow this is how you convert an often-feared SMPS into a piece of audiophile technology.
Hah... yes, I know. But take a look at phono preamps and see how many you find with smps. There are better units than the iFi subjectively for me and iFi is not considered serious hifi but I find it intriguing how well "new" tech works with archaic format. Also, I think that smps is not used just because it is not traditional and does not sell if the price is any higher.
I actually prefer softer touch like Trigon or a bit different like with tubes but that is not for neutral sound nor is it about sensible price.
 
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