Just got that preamplifier from Aiyima brand to make a review, and guess what? This thing is just awesome! It amplifies your music signal to your power amplifier and you can even adjust your bass and treble to get the best sound out of it.. in my case that is amazing! I finally get the eq for playing Youtube music via Bluetooth!

Aiyima Premplifier links：https://www.aiyima.com/collections/tube-preamplifier

Aiyima TUBE-A3 PRO 6J1：https://www.aiyima.com/products/tube-amplifier-preamp-aiyima-a3-pro