Thinking about a purchase and was wondering if anyone has used the 7075 amplifier with electrostatic speakers. They can get to a very low impedance and present a difficult load for an amplifier.

What is the lowest impedance they will go to?

What is the lowest impedance they will go to? A quote from page 2 of the 7075 manual should be heeded but indicates the amp can handle low impedances with adequate reserve.

Loudspeaker Ratings
Your Outlaw Power Amplifier has adequate power to drive most loudspeakers without producing any distortion. Most modern speakers are rated at four to eight ohms nominal impedance, but within some frequency ranges, the impedance may drop to two ohms. The Outlaw is designed with ample power reserves to protect you from experiencing any problems at these low impeadances unless you demand excessively high volume levels.

Due to the high power output capability of your power amplifier, it is important that it not be used with speakers not capable of handling the amplifier’s power output. Before using the amplifier for the first time, make certain that your speakers are capable of handling its rated power output, at the impedance rating of your speakers. Outlaw Audio is not responsible for damage to any speaker system or other component that is caused by using
products whose power rating is lower than that of the amplifier.

Ive seen ML curves that swing as low as 1 ohm depending on the material. Stats are a wicked load to handle, beware.

what speaker specifically?

The speaker is the original Quad electrostatic, now referred to as the ESL57. It is crossed over at 90 HZ to a Janis W2 subwoofer. The Quads dip to an impedance of 2 ohms at a number of points.

Thanks for the responses.

From what I have read about them, the 7075 should be able to drive them. I have seen several reviews which purport them to be more than 100 db efficient yet they cannot be driven to very loud levels without arcing over. Assuming they are vintage speakers, if you damage them they may be hard to get repaired.

I am well aware of the problems of over driving the speakers with a too powerful or unstable amplifier. I have had them over thirty years and the amp I am presently using is almost as old. The amp needs some work so I was looking at possible options.

Should work just fine.

Wasn't the original Quad amp that was paired with the Quad speakers (Mark IV if memory serves me right), a fairly low powered tube amp? I remember demoing them at Jonas Miller (the original M of M&K) back in the mid 70's.

The Quads are limited to a maximum of 32 volts. Anything over that will arc the treble panels. I have had a Bryston 100 watt amp and the solid state Quad amp. They can all arc the speaker if you are not careful. I just don't listen at a loud level anymore so it is not a problem. My biggest concern is if the amplifier is not stable enough at low impedances. An amp that is not very stable can take out both the speakers and itself. The amp I have is voltage limited to 32 volts. This amp is showing it's age and is two channel so I thought I would explore a multi-channel option.