Which taps 8 or 4 ohm for electrostats?


Hi Everyone,

I have a pair of Martin Logan Ascents which are nominal 4 ohms, dipping to 1.2 ohms at 20kHz. I am using the 4 ohm taps on my ARC VT100.

Someone mentioned that these types of speakers tend to look capacitive in nature to the amp, and have greatly varying impedance values. If they are indeed capacitive, it would seem to reason that most of the fundamental notes would be in an area of possibly greater impedance.

Has anyone tried this combination of amp with stats using the 8 ohm tap? Would this be "harder" on the amp (tubes)? I am not to concerned about the 1.2 ohm at 20 KHz, as I can not imagine there is much at that frequency other than over tones.

Any thoughts would be appreciated.

Ron
rlips
I personally think you'd be better off using the 4-ohm taps.

However, I don't think it would hurt the amp to make the comparison as long as you keep to a moderate volume level.

Once you've made the comparison, if the 8-ohm setting sounds better to you, then use it. If not, go back to the 4-ohm taps. My guess is that the 8-ohm taps won't sound as accurate in the lows or the highs with your speakers; but see what you think and let your ears make the decision.
I have ML Prodigy's and am running them with a ARC VT-200. I found the sound to be much more impactful and extended at the frequency extreems going into the 8 ohm taps. The 4 ohms give me a more laid back softer sound (which is nice too). I usually use the the 8 Ohm but I have questioned whether I might be putting a strain on my amp. Guess somebody ought to call ARC.
Good points and questions raised here. My personal experience has been better using the "4 ohm" taps.

Another one I was pondering on (I too own Prodigy's, and own tube amps) is, because of the severe drop in impedence at the high frequency extremes, does this tend to make a tube design "roll them off" a little to some extent?

I seem to get better high frequency extension and "air" with a solid state amp, but the mids are magical.

Can anyone comment on this?