Review on AIYIMA Tube T6 PRO Bluetooth 5.0 Tube Preamplifier - Hi-Fi Headphone Amp, Vacuum Tube Preamp for Home Audio Amplifier, Wireless Receiver, Audio Decoder, Preamp PC-USB DAC with APTX by Rick Booth

I originally wanted to bring some "tube magic" to my desktop audio system. My previous setup consisted of a Lynx Hilo DAC connected directly to Yamaha HS5 + HS8S powered speakers and a subwoofer. I was looking for a cheap tube preamp/headphone amp to do this with. Stumbled across this brand, Aiyima, and a few others here. They all seemed to have similar features and cost around $50-$75. In the end, the main features that attracted me were that this amp has USB and Bluetooth 5.0 connectivity in addition to RCA input and output. Although the price was a bit higher, I chose this one. After reading the reviews here, I decided to order the Riverstone Audio GE5654W Platinum Matched Pair Upgrade tubes as well. I didn't even bother installing standard tubes, so this review is based on three weeks of listening with GE tubes. Let's talk about the sound first. This is fantastic! I've never heard my Yamaha speakers sound so good. I have experience with tube sound. In fact, the setup in my living room consists of Audio Research tube preamps and power amps. On the other hand, if you've never touched tubes, you'll look forward to a ride - a great ride. However, the moment I turned on this amp and fed it some jazz via BT, I couldn't stop smiling. These Yamaha speakers were neutral and sterile on the Hilo, but with this little tube amp they sound smooth and create a very clear soundstage in front of me. My primary listening mode is YouTube Music/Pandora/Spotify apps on an Android phone streaming via Bluetooth LDAC to an Aiyma connected via RCA to a (new) Schitt Jotunheim 2 connected via XLR to Yamaha monitors . Now the Hilo is not part of my audio system at all. What should have cost $50 has since become two new amps and (later) a new DAC (Topping D70s), a pair of planar magnetic headphones and an IEM. My final setup now is to use the USB and/or Bluetooth inputs of the Topping D70 and its DAC. This DAC is A+++. It sounds clear, resolving, but not "digital". Anyway, Topping feeds Aiyima via RCA, which then feeds Jotunheim2. That's how I get the best sound. I'm in music lover's heaven, listening to a jazz stream from my Android phone or my library of FLAC audio files downloaded from my PC by foobar2k. 0dB). I set the Aiyima volume slider to about 1 hour. I found that going from there to the max didn't change the sound and volume much. I also tried Aiyima's BT and USB inputs and both worked fine. USB does not require drivers in Windows 10. BT connects to Android phone directly. I also tried listening a bit with my headphones plugged into Aiyima's single-channel headphone jack. It is in order. I prefer listening to them through the Jotunheim2's balanced headphone jack. As some have said, the RCA pre-out turns itself off as soon as you plug in headphones. This is a very nice feature that I would have liked to see in Schitt Jotunheim2. After all, the amplifier works very efficiently. It's not even warm, and the two tubes aren't hot at all. All in all I like this amp.