Posted by KevinC (M) on December 02, 2003 at 04:32:42

In Reply to: can i use LL1664 INSTEAD OF LL1623 posted by juyonappa on December 02, 2003 at 00:50:40:

You could use either an LL1663/PP or LL1682/PP depending on whether your speakers are closer to 8 ohms (LL1663) or 5 ohms (LL1682). The LL1664/PP has a primary impedance that is too low to be sonically optimal.

The gain of this amp design is actually pretty low by normal standards. I estimate about 10-12dB with ECC182/ECC99/5687 input tubes and about 16-18dB with 5842 input tubes. My "rule" is that for average sensitivity speakers (90dB) one needs about 30dB of gain between the output of the CD player and the speakers. You could use either input tube, but the ECC182/ECC99/5687 family would be my choice.