4 ohm, 8 ohm or 16 ohm tap on amp for quad 57

has anyone compared the affect of using 4, 8 or 16 ohm tap on a tube amplifier when driving a pair of quad 57s ?

if so what do you hear. ?

i am considering a dynaco stereo 70 because it has a 16 ohm tap and is relatively inexpensive for my quads unlimited quad 57s, but am not aware of the advantage of using a 16 ohm tap when driving quad 57s.
I haven't, but if you haven't seen it before here is it's impedance curve:


Lots of interesting links, also, if you click on "reference info" at the left of that page.

The speaker is basically a giant capacitor, as you probably are aware, with its impedance varying all over the map. In the mid-range area, though, it stays mainly in the vicinity of 10 to 12 ohms, which would seem to rule out using the 4 ohm tap. I'd imagine, also, that the choice between 8 and 16 would tend to be amplifier dependent.

-- Al
Hi MrT, the 8 ohm tap is a pretty good bet. You'll have to try it and see how the highs do. If you use the 16 ohm taps, the highs will be rolled off.

There's lots of cool things that you can do the the ST-70 to improve performance- set up right it can be a real performer.
hi ralph:

thanks for the explanatiopn. i am using a vtl deluxe 120--a 5 ohm tap, and the quads sound too focused for my taste.
the stereo 70 might solve my problems.
Ralph, will there be any sonic differences in using your S-30
Mk3 or the MA-60 Mk3s with Quad 57s?
Hi Lula, Some people have had good luck with the S-30. I've not tried it mayself, but I have used the M-60, which works great. With either amplifier, a speaker fuse might not be a bad idea (or be careful with the volume control), as the speaker really can't take more than 35 watts or so, so our amps are capable of making too much power on the speaker.