This is an unofficial review of the Fosi Audio t20 mini tube hybrid amp. Retail price: 85.99$ currently with a 10$ off coupon on Amazon as of writing this review.
I am in love with this little amp. I have 0 qualms recommending it to anyone as a starter headphone/speaker amp. It has no built in dac, but it does have built in bluetooth. This could easily be any ones starting point into the world of hifi audio.
Little bit about the specs. 50 wpc class d CLEAN amplification. I like it at least as much as my sprout100. I have hardly used my sprout100 or the subwoofer connected to it since getting this bad boy. The headphone out I can not find specs on, but it seams to be fairly powerful. It drives my t60rp argons to loud levels, but does not sound quite as good with them as my lyr 3. All my other headphones tho that are not as demanding, I can not tell a difference between it and my lyr 3. It has a really good headphone out.
The stock tubes do good. They are fairly clinical and not that “tubey” sounding. They do an adequate job. I personally replaced them with Riverstone audio’s NOS ge 5654 tubes. They are a little bit warmer and wider in the presentation. But if you like more of a clinical tuning, the stock tubes will do good.
The bass and treble controls work really well and they have a good focus point for each. While I do not have measuring equipment, and can not find specs, I did find a similar fosi tube preamp with the same controls. On that preamp the bass was set to slope up @ 500hz on a sliding scale. The treble was set to 2k on a similar slope. This amp seams to follow that same pattern so I will go with it. Gives you roughly 12b ± at max gain adjustment for both. Mind you on a sloped scale, so +12db at like 30hz and more like +3db at 500hz when maxed out bass for instance. It is a failry level slope tho with no peaks and valleys. So it works well in implementation. Don’t get me wrong, it will not replace a 7 band+ equalizer, but its good for what it is.
This thing is rated at 50 wpc but it feels more tbh. I have yet to go past 12 o’clock on the dial with my martin logan speakers. And that was just for testing purposes as it was insanely loud at 12 o’clock. My usual listening is between 2 clicks and 5 clicks(5 clicks is 9 o’clock). The volume knob is good. Wish it was a little bit bigger. But it does have a fairly satisfying clicking resistance movement to it.
The tube sockets have blue leds in them that causes the tubes to glow blue for 80% of the tube until the filament where the orange glow takes over. May or may not bother you, I am not a big fan, but I can overlook it as I do not stare at my amp all day anyways.
All and all I am really impressed with this little guy. Bought it on a whim to see how it would perform and if it sucked, was planing on using it as a tube preamp for garage speakers. But I feel its to clean and to good for preamp duty. After playing with it some more, I will replace the soundbar(ick) in my bedroom to this + speakers.
For a simple plug and play mostly(no dac) all in one unit, this is a great option. You can hook it up to a pc or stream from your phone and not need any other equipment. Some of these cheap in price but not sound quality chifi amps are a real bargain. How they stand the test of time who knows? This mini amp is built solid by appearances tho. Has aluminum body and a very thick solid plastic face. Comes with mini isolation feet that as far as I can tell work well to not let the tubes pick up vibrations. Granted I have mine on a mini audio rack, so that isolates it as well. But even on the floor it was not picking up anything on the tubes.
One thing to note: When i have it hooked up to my 2 ways with a 10" woofer, I have to crank the volume up much more to get the 10" woofer going. I do not think this would work well for medium+ room’s. But for nearfield or smaller rooms, this is a knockout! Just watch the size of the woofer you are pairing with it. Unless you have some ungodly efficient speakers like klipsch heritage series, I would stick to 6-7" woofers or smaller to get the best out of the amp and speakers.
This may have been the worst review written lol. I feel scatterbrained and all over writing it, but I love this little amp so much I just had to give it some love. I highly recommend it for nearfield/smaller room listening.
or more, expect a total loss of sub-bass.
) and then turning the bass knob to the right. No distortion.