Would switching amps make a big difference?

atmasphere,
The essence of my post is that although the SS amp has more power capability into low vs high impedances, that doesn't mean the SS amp will have a tonal balance skewed toward the HF when driving an electrostatic speaker.  To use our numbers, consider an amp with max capability of 200 watts into 8 ohms, 50 watts into 32 ohms, 800-1600 watts into 1 ohm.  Let this amp drive an electrostatic speaker whose impedance is 1 ohm at 20,000 Hz, 8 ohms at 2500 Hz, 32 ohms at 625 Hz.  This assumes impedance exactly inversely proportional to freq, although I have ignored capacitive reactance, the true parameter.  At 30 watts of output, the amp will put out that same 30 watts into any freq for an even tonal balance.  For 200 watts of output, only freq above about  2500 Hz will be undistorted into that speaker, whereas at freq below 2500 Hz the amp cannot put out as much undistorted power, so I agree that under these conditions the amp will sound bright driving the electrostatic speaker.

At 30 watts of output, the amp will put out that same 30 watts into any freq for an even tonal balance.

@viber6
No, that isn't correct, assuming the amp acts as a voltage source (as almost all solid state amps do, and as some tube amps do to a relatively loose approximation).

In the case of an amp having voltage source characteristics, i.e., very low output impedance, for a given input voltage to the amp it will provide an output **voltage** to the speaker that is essentially the same regardless of frequency, assuming the amp is operated within the limits of its voltage, current, power, and thermal capabilities. And that same voltage will result in more current and consequently more power being delivered into low impedances than into high impedances.

As you are probably aware power delivered into a resistive load equals voltage squared divided by resistance. It's somewhat more complicated than that when capacitive or inductive reactance is involved, but I'm putting that complication aside to try to clarify Ralph's point, which relates to delivery of power (as opposed to voltage) into the speaker. And which relates to frequency response flatness at the output of the speaker, not to frequency response flatness at the output of the amplifier.

Frequency response flatness at the output of the amplifier, on the other hand, is normally defined in terms of how the relation between amplifier output voltage (not power) and amplifier input voltage varies as a function of frequency. That characteristic will indeed be essentially flat in the case of a good quality voltage source amp, as long as the amp is operated within its capabilities. But that is not relevant to the point Ralph was making.

Regards,
-- Al
 

Most speakers are designed to approach a flat voltage response, not power, and amps to be a voltage source. If the source impedance of the amp is rather high (tubes) then there will be an HF roll off. The performance of a solid state amp might sound subjectively brighter but that’s not because it’s tilting up the highs, but because it’s not rolling them off. A speaker designer who designed a speaker with a highly variable impedance AND tuned it for a flat power response would be an idiot.

Most speakers are designed to approach a flat voltage response, not power, and amps to be a voltage source.

Agreed, but of course "most" doesn't mean "all."  It just means a majority.

If the source impedance of the amp is rather high (tubes) then there will be an HF roll off. The performance of a solid state amp might sound subjectively brighter but that’s not because it’s tilting up the highs, but because it’s not rolling them off.

The implication of this statement seems to be that in the case of electrostatic speakers, which are what the thread is addressing, that the tonal balance which results when a solid state amplifier is used is necessarily more correct than the tonal balance that would result with a tube amplifier.  If that is what you are saying I and I believe many others would disagree.  It's worth noting, for example, that the Quad ESL-57, which is revered to this day by many audiophiles, was designed before solid state amplification existed.

Regards,
-- Al
  

cdc2 OP

A strong solid state amp is always a good idea to try with ESLs

This is good advise, get the right amp that can handle Martin Logan Ethos sub 1ohm loads and -phase angles with current and stability.

Stay away from expensive "band aid" fixes like autoformers, save your money and get the right amp for the job instead, your Logans will reward you if you do.

The performance of a solid state amp might sound subjectively brighter but that’s not because it’s tilting up the highs, but because it’s not rolling them off.

I’ve owned many ELS’s this is so true with all Martin Logans, with the right solid state amps that’s stable and that can drive into that sub 1ohm load, you will get the highs that are "there" at the correct intensity and extended, not muted and rolled off.

Cheers George