2. amps-preamps
  3. 1249855754

Amp damping factor?

OK need some technical info. I was told by a reputable source that I should buy an amp that had a high damping factor >100 and preferably closer to 150-200. In looking at this in the specs for many units it seems this might be over-rated. I have been looking at some vintage Mac gear and their numbers are like 10-40? Is that an age thing and modern equipment is just that much better? Or is there a tradeoff I dont know about?
joekapahulu
pauly
1,012 posts
 
Kijanki – an amplifier that has a DF rating is probably something I'll pass on. When specs are written by the marketing department, one never knows just how creative they’ve been.

Regards
Paul
kijanki's avatar
kijanki
4,428 posts
 
Pauly - I agree. Specifications are very flexible and often misleading. Amplifier (and any other) design is a series of compromises and when you see an amp with exceptionally high DF and extremely low THD something else has to give - the sound.

Joekapahulu - I wouldn't pay too much attention to DF. For instance Atmasphere MA-1 amps have DF<1 (tube amp without output transformer) but sound great according to 6Moons review ("gigantic imaging, excellent dynamics, frequency extension and potent music-making").
shadorne's avatar
Ag insider logo xs@2x
shadorne
7,477 posts
 
An amp doesn't have a damping factor. Damping factor is the ratio of the rated impedance of the loudspeaker to the source impedance.

The convention is to report Damping Factor into an 8 ohm load - so for pratical purposes one might say that power amps do indeed have a Damping Factor.

It can be over rated as the woofer drive motor and mechanical as well as acoustic suspension can play a much bigger role. A high damping factor amp is not going to fix a badly designed speaker with low cost drivers with cheap (small) motor - that will be putting lipstick on a pig.
magfan
1,583 posts
 
1st, DF is just a spec, If all manu. measure the same, you should be able to compare. Not that this would make it mean any more or less!

Also, propagation delay is as good a reason as any why certain bi-amp combinations don't work out. 1milisecond is roughly 14" at the speed of sound and will result in phase/time smear effects. Even I can hear that! Pair a fast amp with a slow amp and you could quite possibly get to that level.
bifwynne
2,206 posts
 
Sorry for the late post, but I have a question about DF. I own an ARC tube amp. I just happened to notice that most of the tube amps in the ARC line have pretty low DFs, e.g, less than 20. Nevertheless, most of the ARC tube amps sound great. So what's all the hubbabaloo about DF?? Does it matter that most if not all ARC tube amps use output trannys?
More to discover