Posted by Damir [ 213.202.69.176 ] on February 14, 2005 at 16:18:30:
In Reply to: Still a bit of a generalization, but... posted by Wayne Parham on February 14, 2005 at 15:01:37:
Hmm... When I try to compare "proper" (by my "standards", anyway:-)) way for making PP or SE amp, PP is more expensive...:-).
Yes, one can use 1N4007 bridge, 220uF electrolytic cap for the B+ (and say, another RC filter for the driver), with goal "everything cancels in OPT"... Then use simple (or low/medium quality) OPT, class AB, common pentode/beam tetrode (say EL34, KT88, or so), UL connection, NFB "loop" of 15 db or more... Then "ordinary" LTP phase splitter based on, say 12AT7 or so with 12AU7 "input" tube, etc.
But, if we use similar principles like in SE building - careful selection of linear tubes for the driver and output (DHT), class A operating point with carefully chosen high-quality OPT, LC-style PS with HQ oversized PT(s) (plus maybe additional heater/filaments transformers), MKP (non-electrolitic PS caps), no NFB loop, say - monobloc construction, phase splitter with real balance (CCS), etc. - we can really spend more for PP amp...but, I`m sure that the results will be worth it... 