I know the Sunfire amps are popular here with the Martin Logan crowd.
The Sunfire amps have a feature where you can use a current output on the main speakers to give them a more 'tube like' sound. I've never actually heard from anyone what they though of these. How many folks use this feature? Can anyone describe how they think they sound?
I'm sure everyone who has ML's + Sunfire has at least TRIED it - what did you think? Did you leave it that way?
/edit: This should have been in the Amplifier sub forum, I fear. I assume a moderator will move it for me, sorry to use up some of your time Tom!
Actually, this is generally relevant to all. Here's why:
The big difference between the two output styles on a Sunfire is resistance. The Current source features 1 Ohm resistance, voltage has essentially zero resistance.
Electrostats change their frequency response characteristics depending on the resistance of the input network.
Without getting into the vagaries of Rep and other EE stuff, it basically affects how the combination of ESL audio step-up transformer interacts with the panel.
The fundamental effect is that added resistance in the input causes a dip in the high-frequency response of the speaker.
So whether it’s a ‘special’ output type on an amp, or ‘special’ speaker wires (some esoteric wires have boxes that contain elements that add resistance and/or capacitance), these WILL affect the frequency response of the ESL.
I specifically
tested this during my SL3XC build, and in this picture, I show the significant change in response between no resistance between amp and ESL, and adding 1 Ohm of resistance.
As you can see, pretty major drop off in high-frequency response from 5K on, and down by more than 5dB at 10KHz.
(note: the rise at 11KHz in this shot is due to absolutely no crossover components in the path before the ESL audio step-up transformer, usually there is some resistance (Rep) in the path that tames that peak).