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Pro-Ject Phono Box DC MM/MC Phono Preamp Review

Rate this phono stage:

  • 1. Poor (headless panther)

    Votes: 3 2.5%
  • 2. Not terrible (postman panther)

    Votes: 14 11.9%
  • 3. Fine (happy panther)

    Votes: 69 58.5%
  • 4. Great (golfing panther)

    Votes: 32 27.1%

  • Total voters
    118

amirm

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This is a review and detailed measurements of the Pro-Ject Phono Box DC MM/MC Phono stage. It is on kind loan from a member and costs US $129.
Pro-Ject Phono Box DC Preamp stage moving magnet coil budget review.jpg


The box is non-descript but it is made out of heavy gauge steel. There are no controls as you see. Here is the back panel:
Pro-Ject Phono Box DC Preamp stage moving magnet coil budget back panel power supply review.jpg

Nice to see support for both moving magnet and moving coil as the latter is sometimes left out in budget phono preamplifiers. Let's test it and see how it performs.

Pro-Ject Phono Box DC MM/MC Phono Preamp Measurements
Let's start with moving magnet mode:
Pro-Ject Phono Box Preamp stage moving magnet measurement.png

With highest distortion at -100 dB, that is not an issue for the format. Performance is dominated by mains noise which is typical for the class. Gain is right on at 40 dB.

Moving coil mode naturally brings high penalty in noise department due to much higher gain:
Pro-Ject Phono Box Preamp stage moving coil measurement.png


I was totally impressed by the implementation of RIAA equalization:
Pro-Ject Phono Box Preamp stage moving magnet frequency response measurement.png

It is rare that we see such flat response regardless of price! Would have been nice to have a high pass filter though to deal with LP rumble and other low frequency noise but that would have increased the cost.

Headroom is quite good for the class:
Pro-Ject Phono Box Preamp stage distortion vs input level headroom measurement.png


But degrades as frequencies go up:
Pro-Ject Phono Box DC Preamp stage moving magnet distortion vs frequency measurement.png


Conclusions
Sometimes a product, despite its low cost, does everything right and such is the case with Phono Box DC. It has excellent RIAA equalization which many higher priced phono stages miss. Nothing like saying what you are going to do and delivering on that!

I am going to recommend the Pro-Ject Phono Box DC MM/MC Phono Preamp.

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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/
 
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Could a home made RC network be triple stacked for a steeper roll-off and suffice for the high pass filter? Or is there something special about the high pass filters used in phono preamps?
 
Thanks for the review
Anyone knows what is the difference, if any, with the phono box non "DC" avaiyin EU (99eur). They look identical.
 
Yeah, without that rumble filter those woofers are going to pump, especially on warped records.

It's amazing to see how much some companies have charged for Phono preamps in the past, well upwards of $3-5k for some of the bigger names. Towards the end of the '80's and into the early '90's, having a high end phono setup meant having a separate box for the phono preamp (in some instances a separate box for its power supply as well) and then a box for the line preamplifier which could also in turn have its own power supply complete with umbilical, so four boxes before we see the DAC with a separate box for the CD transport.

And each one of those boxes would cost upwards of $3-5k, not counting the price of the Turntable, cartridge, isolation platform, and tone arm. And all for a way of rendering sound from a format having a theoretical maximum Sinad of 65-70 db to be generous about it.
 
It would be nice to see how this ranks as far as SINAD and headroom are concerned. That equalization is sexy. Is this the Millennium Falcon of phono preamps?
 
It would be nice to see how this ranks as far as SINAD and headroom are concerned.
Mains noise impacts these products a lot so I have hesitated to create a chart for SINAD.
 
Maybe you can manage without the HPF if you got HPF elsewhere in the system , as for example in my subwoofers and active speakers who has this .
But i one would have to waste headroom by digitizing rumble for it to be removed later , hence it gets a "fine" vote :) from me .
 
Looking at the numbers, Schiit Mani 2 might be the better cheap phono pre and has a rumble filter and you could argue the same for the ART DJ. Suffice to say that there are several cheapies that will make the most of the format.
 
That equalization is sexy.

You find RIAA deviation "sexy"? ;)

It's about +0.1dB and -0.2dB. Pretty good but not spectacular, but very good for the price.

The issue with no infrasonic filter is serious. Simply because the people most likely to buy this, will own/buy some modern, bare bones, stripped down preamplifier with no filters. If they have a preamp with a low filter, it will most likely have an inbuilt phono stage anyway, so they aren't the customers.
 
Nice piece.
What's the moving coil input impedance?
Nick
 
Nice wee box, thanks Amirm.

I'm wondering who would buy this though. Anyone with MC will want more options (or they are just chucking money away to be fashionable
... quite possible).
For MM too, I'd have thought the lack of filter would be a problem. Anyone who doesn't know why they want a filter probably has a TT with a built-in phono (massive generalisation, no offence intended)
 
You may not suffer from the lack of HPF if you conect this to the analog in on some lifestyle active as Sonos or bluesound etc ?

been there in the bad old days with cones flapping on your bassreflex speakers :) the combo of BR speakers and no subsonic filter was all to common for some reason.
 
Yeah, without that rumble filter those woofers are going to pump, especially on warped records.

It's amazing to see how much some companies have charged for Phono preamps in the past, well upwards of $3-5k for some of the bigger names. Towards the end of the '80's and into the early '90's, having a high end phono setup meant having a separate box for the phono preamp (in some instances a separate box for its power supply as well) and then a box for the line preamplifier which could also in turn have its own power supply complete with umbilical, so four boxes before we see the DAC with a separate box for the CD transport.

And each one of those boxes would cost upwards of $3-5k, not counting the price of the Turntable, cartridge, isolation platform, and tone arm. And all for a way of rendering sound from a format having a theoretical maximum Sinad of 65-70 db to be generous about it.
The unwanted LF will depend a lot on how well the tonearm-cartridge mass is matched to the cartridge compliance and damping. I wonder how well that is understood by those who've joined the "vinyl revival"?
 
For the market level, the price is aimed for, They should have done without MC input, and added the rumble filter, because:
- at this price level, the usual client has a low to medium quality record player, playing possibly warped LPs (of varying degree). He just wants to keep his LPs going.
- I doubt anybody with a decent MC cartridge would be looking at headamps, at this price level.
If I was in the market for a headamp, for my multi thousand pound record player, with an equally expensive MC cartridge, playing my treasured LPs through my £10K amp and £20K speakers (are you getting the picture?) then I would be looking at something like:
- https://www.leema-acoustics.com/product.html?prid=50
- or at the very least

It would be interesting, if someone could send either of those in for a measurement!
 
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