This is a review and detailed measurements of the Hypex DIY balanced Preamplifier and headphone amplifier Kit. It was sent by the company and kindly assembled by @Rick Sykora. It costs € 1.225,00 excl. VAT (US $1,331).
I very much like the larger form factor here and especially the very large graphical display. Alas, as you see, very small fonts are used to show the input and volume level. On power up you see a massive logo of the company and I expected to see that here. Good news is that the display and operation is quite responsive. A remote control is provided in addition to rich set of capabilities as far as renaming inputs, setting gain, balance, etc. Back panel configuration seemed puzzling to me:
I had to read the manual to confirm that there are two XLR outputs but only one input! Seems backward to me. What is the use for dual set of XLR outputs? In my system I have two XLR sources so this rules it out for my own configuration. There is RCA to balanced configuration although some would want to see RCA output as well.
The right blank cover is interesting as the company talks about DAC, phono stage, streamer and even some kind of EQ capability to go there!
Digital volume control is provided and reassuring set of relays click when changing inputs.
Let's see how it measures.
DIY ClassD Preamplifier Measurements
I started with XLR in/out and adjusted the volume to get unity gain:
This is most excellent with vanishingly low distortion at -140 dB! Some noise pulls SINAD down to still a transparent value of 119 dB. Switching to RCA input with 2 volts in, costs you a few dBs but still transparent:
Noise performance is excellent:
Frequency response is very extended and ruler flat in audible band:
Crosstalk is near state of the art:
IMD graph shows slightly higher noise than best there is but still excellent:
Similarly to what we see as far as distortion relative to frequency:
And level:
Hypex DIY Preamplifier Headphone Measurements
Let's start with our unity gain dashboard measurements:
This is excellent performance and good attempt at getting into the room with best of the best:
SNR is not as good as it could be because there is no low/negative gain mode to reduce noise:
This only impacts very sensitive IEMs though:
Other the aforementioned slight noise penalty, the level of output with 300 ohm load is very good:
I like to see minimum of 100 milliwatts which we have. Then again, for desktop products, we are used to 300+ milliwatts.
I was surprised to see a less competitive showing with 32 ohm load:
We are current limited as we see better in this graph:
I expected to see a "checklist" headphone amp but this performance is a lot better especially if you use high impedance headphones.
Hypex DIY Preamplifier Listening Tests
I drove the unit using RME ADI-2 Pro balanced output and listening using Sennheiser HD650. The experience was superb with excellent detail and dynamics. There was plenty of volume, capable of getting good bass out of this headphone. As measurements predict, switching to my everyday Dan Clark Stealth headphone resulted in static and distortion at anything but very mild volume level. Really not useful with this power hungry headphone.
Conclusions
We are used to seeing power amplifiers from Hypex. It is nice to see them get into preamplifiers by producing a unit with exceptionally low distortion and quite competitive noise performance. I like the large form factor and display but wish the company revises the firmware to show larger text for input and volume level. Having two balanced output at the expensive of another balanced input doesn't make sense to me but maybe one of you will enlighten me.
I expected the headphone amp to be as we say in the industry, "phoned in," but it actually turned in very good performance for high impedance headphones. It should also be OK with lower impedance headphones as long as they are sensitive.
I am happy to put the Hypex DIY Preamplifier and Headphone Amp Kit on my recommended list. Look forward to new option cards for it!
-----------
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/
I very much like the larger form factor here and especially the very large graphical display. Alas, as you see, very small fonts are used to show the input and volume level. On power up you see a massive logo of the company and I expected to see that here. Good news is that the display and operation is quite responsive. A remote control is provided in addition to rich set of capabilities as far as renaming inputs, setting gain, balance, etc. Back panel configuration seemed puzzling to me:
I had to read the manual to confirm that there are two XLR outputs but only one input! Seems backward to me. What is the use for dual set of XLR outputs? In my system I have two XLR sources so this rules it out for my own configuration. There is RCA to balanced configuration although some would want to see RCA output as well.
The right blank cover is interesting as the company talks about DAC, phono stage, streamer and even some kind of EQ capability to go there!
Digital volume control is provided and reassuring set of relays click when changing inputs.
Let's see how it measures.
DIY ClassD Preamplifier Measurements
I started with XLR in/out and adjusted the volume to get unity gain:
This is most excellent with vanishingly low distortion at -140 dB! Some noise pulls SINAD down to still a transparent value of 119 dB. Switching to RCA input with 2 volts in, costs you a few dBs but still transparent:
Noise performance is excellent:
Frequency response is very extended and ruler flat in audible band:
Crosstalk is near state of the art:
IMD graph shows slightly higher noise than best there is but still excellent:
Similarly to what we see as far as distortion relative to frequency:
And level:
Hypex DIY Preamplifier Headphone Measurements
Let's start with our unity gain dashboard measurements:
This is excellent performance and good attempt at getting into the room with best of the best:
SNR is not as good as it could be because there is no low/negative gain mode to reduce noise:
This only impacts very sensitive IEMs though:
Other the aforementioned slight noise penalty, the level of output with 300 ohm load is very good:
I like to see minimum of 100 milliwatts which we have. Then again, for desktop products, we are used to 300+ milliwatts.
I was surprised to see a less competitive showing with 32 ohm load:
We are current limited as we see better in this graph:
I expected to see a "checklist" headphone amp but this performance is a lot better especially if you use high impedance headphones.
Hypex DIY Preamplifier Listening Tests
I drove the unit using RME ADI-2 Pro balanced output and listening using Sennheiser HD650. The experience was superb with excellent detail and dynamics. There was plenty of volume, capable of getting good bass out of this headphone. As measurements predict, switching to my everyday Dan Clark Stealth headphone resulted in static and distortion at anything but very mild volume level. Really not useful with this power hungry headphone.
Conclusions
We are used to seeing power amplifiers from Hypex. It is nice to see them get into preamplifiers by producing a unit with exceptionally low distortion and quite competitive noise performance. I like the large form factor and display but wish the company revises the firmware to show larger text for input and volume level. Having two balanced output at the expensive of another balanced input doesn't make sense to me but maybe one of you will enlighten me.
I expected the headphone amp to be as we say in the industry, "phoned in," but it actually turned in very good performance for high impedance headphones. It should also be OK with lower impedance headphones as long as they are sensitive.
I am happy to put the Hypex DIY Preamplifier and Headphone Amp Kit on my recommended list. Look forward to new option cards for it!
-----------
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/
