This is a review and detailed measurements of the AIYIMA stereo tube based balanced preamplifier. It was sent to me by the company and costs US $180.
This is an unexpected and attractive design! I love the large and stylish volume control which can be managed using the supplied remote control. The volume function is a bit overloaded with it being power button, the input selector, and mute but is manageable. The back really surprised me:
Did not expect XLR balanced input and out let alone trigger support! The included external supply is pretty small and nicely sports a ton of safety logos which inspire confidence.
I must say, my bias is that such a products are horror shows when it comes to measurements. Company shows measurements that are too good to be true for the class. Let's see if we can verify them.
AIYIMA T20 Preamp Measurements
I started with the XLR in/out and set the input to 4 volts, and adjusted the volume to get the same voltage out:
I expected a SINAD of 40 to 60 dB but here, we are at 81 dB! Yes, we have more distortion than a solid state design but if one wants that, it would not be a tube product. Using RCA produces similar performance:
In the interest of time, I focused on balanced I/O from here on starting with SNR measurement:
Wow, this is quite good! I don't think I have tested a tube product with such low noise.
Frequency response is also very good for class:
As is crosstalk:
IMD test shows higher noise than state of the art transistor pre-amp but again, for this class it is quite good:
I expected some increase in distortion at low frequencies but it is less than what I thought we would see:
The digitally control volume produces perfect channel matching:
Conclusions
Amazing what happens when a company is focused on proper engineering building a tube product. No unnecessary noise and distortion are thrown in there as is the standard for this class of product. Modernization is in play with balanced input/output, remote control, digital volume control/display and trigger automation support. Really, can't ask AIYIMA to do more. They show that using tubes in an amplifier doesn't need to bring with it embarrassment in objective performance.
I am going to recommend the AIYIMA T20 preamplifier. Kudos for the company showing that such a product can be done well, outclassing many solid state products!
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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/
This is an unexpected and attractive design! I love the large and stylish volume control which can be managed using the supplied remote control. The volume function is a bit overloaded with it being power button, the input selector, and mute but is manageable. The back really surprised me:
Did not expect XLR balanced input and out let alone trigger support! The included external supply is pretty small and nicely sports a ton of safety logos which inspire confidence.
I must say, my bias is that such a products are horror shows when it comes to measurements. Company shows measurements that are too good to be true for the class. Let's see if we can verify them.
AIYIMA T20 Preamp Measurements
I started with the XLR in/out and set the input to 4 volts, and adjusted the volume to get the same voltage out:
I expected a SINAD of 40 to 60 dB but here, we are at 81 dB! Yes, we have more distortion than a solid state design but if one wants that, it would not be a tube product. Using RCA produces similar performance:
In the interest of time, I focused on balanced I/O from here on starting with SNR measurement:
Wow, this is quite good! I don't think I have tested a tube product with such low noise.
Frequency response is also very good for class:
As is crosstalk:
IMD test shows higher noise than state of the art transistor pre-amp but again, for this class it is quite good:
I expected some increase in distortion at low frequencies but it is less than what I thought we would see:
The digitally control volume produces perfect channel matching:
Conclusions
Amazing what happens when a company is focused on proper engineering building a tube product. No unnecessary noise and distortion are thrown in there as is the standard for this class of product. Modernization is in play with balanced input/output, remote control, digital volume control/display and trigger automation support. Really, can't ask AIYIMA to do more. They show that using tubes in an amplifier doesn't need to bring with it embarrassment in objective performance.
I am going to recommend the AIYIMA T20 preamplifier. Kudos for the company showing that such a product can be done well, outclassing many solid state products!
------------
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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. Otherwise, it only worsens the parameters. SOTA opamps + vintage tube, what a mess! 
