Review on Premium P1 Bluetooth 5.0 Vacuum Tube Preamplifier: Enhance Your Audio Experience with Hi-Fi Valve Headphone Amplification, Wireless Connectivity, USB DAC, and APTX-HD Support by Tommy Woods

It's been over a year and I still love it. I still use this little amp and love it. I was initially disappointed with the USB input as there was a lot of noise when connecting to a desktop computer. This amp lacks an optical input which would make it almost perfect. But last summer I hooked up all of our computers to a panamax surge protector/line cleaner to protect them during a lightning storm (yes, we have extension cords everywhere). It was some time after the cheap optical DAC died and I tried USB. No noise! The noise was caused by AC power, not my computer. So I have now connected the amplifier (USB). I've heard Bluetooth from various sources and if you don't have APTX on your device (phone) then it's not outstanding, but basic Bluetooth has never been so great for sound. I have it on my old ASUS phone and it's now my source of music when listening via bluetooth. First review: I really like this little amp. It's hard to describe, but I just enjoy music more through this amp than straight from the source. If you have a Qualcomm Bluetooth source, it sounds phenomenal. The USB input is also pure magic. I haven't tried RCA input or RCA output yet. I love that it has an RCA output on the back. So if you want to use it as a preamp, you don't have to run a cable out of the headphone jack and run it to a power amp. As a purist, I think it's good that you can switch off the tone controls. That was crucial for me. I replaced the standard tubes with tiny GE tubes but honestly didn't notice any difference in sound quality. But the standard lamps are very large and not as portable as the small GE lamps. But for the price of GE tubes I'd say they're worth it if you bring an amp (I take mine to work). About lamps. Be prepared to play around with them until you have all the pins aligned (you may have to bend the pins slightly to get them in). I found a bit of drama and profanity helped bond them. The wall wart has a damn bright LED. It can act as a night light. But nothing a piece of tape couldn't do. I'm not a big fan of the volume control. It's indented and a one-click change is too much for my liking. Not as bad as the big volume jumps on an Android phone, but still more than I prefer.