[New Upgraded] AIYIMA A3 PRO GE5654 Tube Preamplifier Bluetooth 5.0 with Treble & Bass Adjustment DC12V HiFi Audio Preamp for Home Audio Amplifier System(Black+BT 5.0)

Great tube buffer/pre-amp for those who have been wanting to get their toes wet in the tube world. I have 3 of these now, each on different systems with different modifications. About to buy a fourth and fifth.First off, GE JAN5654W tubes are commonly recommended for a reason. They are inexpensive and very easy to find, yet they are provide a significant improvement in overall sound dynamics, clarity, soundstage, natural warmth and detail compared to the tubes that are included. The Soviet Military 6J1-PV tubes are a little more money but are my favorite sounding tubes so far, and I highly recommend them.Second, another easy and inexpensive upgrade is the power supply. A 12V 1AMP power supply is included and it works fine. Upgrading to an inexpensive 12V 3AMP power supply is a no brainer.Third, for those willing to grab a few basic tools and disassemble the unit, the AIYIMA 6J1 has some hot rodding potential, mainly in replacing/upgrading the OP amps and electrolytic capacitors. Very easy to do and cheap.OP Amps: These are very easy to replace, require no soldering, and can give you the biggest improvement in sound quality, even more than the tubes themselves. Simply remove and install the new ones making sure the dots line up with where the old ones were.On my systems, OPA2134PA OP amps sound fantasic, are only $6.00 each, and so far are my favorite non-MUSES chip. The almighty MUSES line of chips are a considerable investment and cost about $50... each. That's a lot to spend if you need or want two of them. But as they say... you get what you pay for. The MUSES02 is very popular and I think it sounds great, but I didn't find it nearly as amazing as the MUSES01's ghost-like presence. I'm now using the 02 in the bass slot, and the 01 for the treble. Sounds fantastic! Discrete amplifiers like Sparcos are available as well, but get even more expensive. I have yet to try them.Capacitors: if you are handy with a soldering iron, pop out the two light blue electrolytic capacitors and replace them with WIMA MKS4F041005B00JSSD film caps. They are only a dollar a piece, and the difference in sound is ridiculous. I recommend Digikey or Mouser when purchasing parts.Cheap tube magic!

Grade: BI picked this preamp to give my Pro-Ject Carbon TT a nice warm sound off a digital 2.1 audio system. The result is nice but not as noticable as I thought it'd be.The unit looks amazing with the subtle glow of the tubes and a slick, sturdy black and silver case. It came well protected and instructions were easy enough to be up and running in 5 minutes flat. The knobs are super useful and I can't stress how nice it is having extra Bluetooth attached to the SS. It loses points when it comes to the clicks bw levels on the knobs. Makes it feel cheaper that it should. Overall, its still is a sturdy, sleek looking preamp that provides a little bump in sound or can completely upgrade your system with that BT.TLDR: Well built unit with a nice look but outside of BT only gives your system a slight bump.

For $45 I had some doubt about this unit. It arrived very quickly. And like others have said the build is surprisingly solid.The control knobs smoothness did portend good things to come.The instructions were, of course, worthless. But if you have any audio experience it was easy to figure out and hook up and pairing to my phone, Galaxy 5 Player (yes, it is still working), and my Samsung tablet was a breeze for all three devices.I plugged it into my integrated stereo amp and ran some test audio by playing songs on Youtube; everything from Green Day to Beethoven's 6th.I was surprised at how impressed I was with this little powerhouse. (I played Powerhouse too.) I left the unit controls in neutral for most of the testing and that seemed the best spot; but the three controls did, indeed, work properly adjusting their corresponding three parameters (treble, bass, volume.)I played FLAC and MP3 files along with the YouTube songs. And there was great presence from this preamp's output.I purchased this unit solely so I could do some really lazy music listening from my couch when I don't feel like getting up to clean and flip vinyl every 23 minutes.I frankly can't discern if the fact this unit uses tubes makes a real difference without trying a similar solid state preamp. But it sure seemed to my mind's ear that there was greater separation and smoother tone with tubes.I did order the GE tubes for this unit but they haven't arrived yet. If the new tubes make a significant difference then I will know that all of those tube amp fanatics are really onto something.I have already gotten my $45 worth of listening enjoyment out of this amp. A delight, not a disappointment.The GE tubes arrived. And they were dated "1987" but they still worked. I put them in and let them warm up for several days.And then.........Couldn't hear a lick of difference. Maybe my ears are more gross than other reviewers' are. I put the tubes it came with and let them warm up and really can't tell much difference at all.I put the GE tubes back in just because and the original tubes are in a little box "just in case".

The sound is good for the price, but the build quality is poor. Had a hard time to install the two tubes into the sockets which are out of alignment with the pins on the tubes. I tried the tubes on other preamp and they fit very well, without having to spend a long time just to have them sit into the sockets.

these little chinese tube pre amps amaze me, this is my second one i have the fosi p1 and this guy. LOVE them both! for $50 dollars best piece of audio equipment you can get.helps bring so much more of a 3d effect to the music for me . Its almost like you can swim through the music if that makes sense? everything is more seperated and clear. not just a bunch of noise coming at you. but beautiful ,colorful , music from all around you. it seems silly but true!