I have a 45 amp that's a clone of the Korneff design. Basic, nicely built amp. Worth about $700. If you have horns 100dB+, this could be a fine choice. My speakers aren't quite that sensitive, and even if I wanted to, I couldn't use big horns in a room this size. So in trading I'd be looking for a good tube amp with 5-20wpc. Message me with what you have and any questions, I'll provide details and pics of my 45.
Thanks!
