What kind of power wakes up electrostatic speakers

A friend of mine recently was trying to upgrade the amplifier to drive his Martin Logan CLS speakers, he was driving them with a Quad 606 (original version) and it was sort of managing OK. He was really looking for a substantial upgrade and he tried a Krell 300i which was onsale.

The Krell was not in a position to drive them at realistic levels even at full volume. The Quad somehow was playing much louder and still had room to spare. We were really surprised. Switched his two CD players, three speakers, and the two amps. None of the equipment had any problem including the Krell which was driving the Maggies as well as large dual concentric Tannoy speaker. We were unable to figure out why Krell on Martin Logan CLS sounded like a 25 watter. Nothing made sense to us.

What could be the reason for such low volumes on the CLS? Is Krell 300i a bad match for CLS? Is the power supply of just 400v in Krell not able to cope with the load? Is it the matter of voltage versus current?

Can anyone shed some light on this issue for our better understanding?

Yesterday I was at the friends place as he invited me to listen to his new find. I was surprised to see a vintage Sansui Au-111 tube amp which was glowing and driving the CLS in a way which was shocking. This combination was so far the best we came across. I was accompanied by another friend who is actually into the bottles (Cary 2A3, Alon Adrianna's, Wadia 850) and he too was very impressed with the sound that was coming out of the CLS.

Now the friend with the CLS knows which direction he needs to go. Tubes and nothing else.

Meanwhile the Sansui which is a vintage model circa 1965 is under servicing and cleaning, including changing to new set of tubes. We will have a go at it again and see what the results are.

I thought I should update my finding on this thread.

Sean, if you are reading this, thanks for the detailed explanation. I appreciate it>