This is a review and detailed measurements of the SMSL PH-1 Phono Stage and headphone amplifier. It was sent to me by Aoshida Audio and costs US $70.
The volume for the headphone output was very shallow and difficult to rotate. I did not measure it. The rest of the box looks fine with a fixed gain and simply on-off switch in the front. Let's see how it measures.
The unit is powered by a barrel connector. A USB to that connector is supplied and that is how I tested it.
SMSL PH-1 Phono Stage Measurements
I started by plugging in the USB cable into the hub in my monitor which I use to test all USB devices. Result was startlingly bad:
We see ton of interference from USB connection. I almost gave up at this time but decided to use a USB adapter I had sitting around. That, produced far better results:
SINAD is dominated by the mains noise. Company measurements don't show that so it is possible that it is power supply dependent. Going with what we have, performance is a bit below average:
Most important measurement is the implementation of RIAA equalization:
As you see, at either end of the audible spectrum, response strongly deviates. The low frequency response is not too bad in the way it would filter out LP rumble but the high frequency peaking may indicate onset of oscillation.
For headroom testing, 50 mv is not bad but I want to see 100 mv (at 1 kHz). Fortunately the implementation is one of the rare ones where headroom is hardly lost at higher frequencies:
Distortion is extremely low, regardless of price:
Conclusions
The PH-1 is hard to judge. Price is of course very attractive but that comes partially from eliminating the external power supply. This leaves the user with having to pick a source which may contribute significant amount of noise due to high gain of the phono stage. Frequency response has major errors but not in the core audio band. Headroom is modest but on the other hand, doesn't vary much with frequency. Finally, distortion is quite low.
Personally I like to see a more perfect implementation at higher cost so can't recommend the PH-1. But you may decide otherwise.
------------
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/
The volume for the headphone output was very shallow and difficult to rotate. I did not measure it. The rest of the box looks fine with a fixed gain and simply on-off switch in the front. Let's see how it measures.
The unit is powered by a barrel connector. A USB to that connector is supplied and that is how I tested it.
SMSL PH-1 Phono Stage Measurements
I started by plugging in the USB cable into the hub in my monitor which I use to test all USB devices. Result was startlingly bad:
We see ton of interference from USB connection. I almost gave up at this time but decided to use a USB adapter I had sitting around. That, produced far better results:
SINAD is dominated by the mains noise. Company measurements don't show that so it is possible that it is power supply dependent. Going with what we have, performance is a bit below average:
Most important measurement is the implementation of RIAA equalization:
As you see, at either end of the audible spectrum, response strongly deviates. The low frequency response is not too bad in the way it would filter out LP rumble but the high frequency peaking may indicate onset of oscillation.
For headroom testing, 50 mv is not bad but I want to see 100 mv (at 1 kHz). Fortunately the implementation is one of the rare ones where headroom is hardly lost at higher frequencies:
Distortion is extremely low, regardless of price:
Conclusions
The PH-1 is hard to judge. Price is of course very attractive but that comes partially from eliminating the external power supply. This leaves the user with having to pick a source which may contribute significant amount of noise due to high gain of the phono stage. Frequency response has major errors but not in the core audio band. Headroom is modest but on the other hand, doesn't vary much with frequency. Finally, distortion is quite low.
Personally I like to see a more perfect implementation at higher cost so can't recommend the PH-1. But you may decide otherwise.
------------
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/
