I'm curious to listen the difference with GE 5654 W even the chinese copy (10$ a pair!!!) the original "JAN" RCA are a bit better but the price is not the same... (they are way better than the russian tube supplied with this preamp) That sound really great on my Marantz 1070 f(ull recap and small upgrade like better caps/circuit board/cables) and my Senheiser HD 600 headphones,i never found something better with the Senheiser than this 1070 and these "stupid small preamp and the good tubes..... ;)

Does it sound better than that Adcom pre amp?