Ohm load for SET Amps


I've always heard/read/searched that 8-ohm or higher loads are ideal for tube amps.  Speakers are "tube friendly".  I've never really understood why that is the case.  Could anyone with much more experience/wisdom than myself (most, I'd imagine) explain why this is the case?  What would happen if one were to use 4-ohm speakers with a SET amp?

While I have some foundation of physics and electronics, I'm far from an electrical engineer.  

The main reason I ask is because I have a pair of 845 SET's, and would like to consider speakers rated at 4-ohm.  My 845's have 4, 8, 16 ohm taps.

Thanks for any help!
cyberbob

Showing 1 response by cyberbob

Thanks for all the input guys!  It seems like the main issue is not getting the most out of your amp, whether from increased distortion, or reduced range, or reduced efficiency, but there isn't anything inherently harmful to the amp, per se.

The concept of impedance curves and matching is an interesting one, and helps clarify a bit in my mind why some amps/speakers may "play well together".

I do agree, and wish, all high end audio speakers were minimum 8-ohm.  My problem is that I've been out of the game for a long time.  All of the high efficiency speakers I've heard were not to my liking, regardless of the amp, and I really liked the overall package of the 845 tube.  It's been a bit difficult to find a decently efficient 8-ohm speaker *sigh*