Would Atmasphere M1 work with ML Ascent i speakers

Traditionally, ESLs and OTLs have been the match made in heaven since the 1950s. But some modern ESL manufacturers have wanted to tap the solid state market, which is problematic (see http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php for why).

One of the ways they have tried to solve the drive issue is to make the overall impedance of the ESL lower so a transistor amp can make power on the speaker. This often makes the ESL unplayable with any tube amp. However this problem is often easily solved by using a set of ZEROs http://www.zeroimpedance.com to raise the impedance.

The funny thing about this is that most transistor amps actually sound better driving lower impedances by using the ZEROs as well! The simple fact of the matter is that there is no good rationalization for lower impedance speakers if sound quality is your goal, regardless of the amplifier technology. If **sound pressure** is your goal, then there is a slight advantage if you have a transistor amp.

I think Ralph has heard my story before and I agree about impedance matching. Many years ago I had MA-1s driving speakers that were rated at 4 ohms. However, the measured impedance curve dipped below 3 ohms in both the bass and treble range. In many ways those amps sounded wonderful but not with complex or loud music. That is not a criticism of the amps, merely a recommendation to find the right tool to do the job.

As for a multi-channel SS receiver being able to drive the Ascent i, that seems completely irrelevant to driving them with an OTL tube amp in my perspective.

hi Pal, i do own a ML Ascent i, it is in my second system.
Generally i would say almost every amp(even multichannel receivers) in the market are able to drive the ML speakers, but not to a sonic greatness that may leave you satisfied. Depending on the loudness you normally hear, your personal taste, the music genre(i said this because certain music don't have much bass), you may find MA-1 could be the best match but to other it could be dreadful.
as for talk of impedance, it is generally not easy to have a capable amp to drive ML well, including SS. Depending on speaker load, the output devices (transistors in SS, tubes in SET,OTL) may not always run linearly to drive the electrostatics. It is this complexity that make different amp sound differently. If the music that you listen to does not goes so high in freq(or very low freq. because Ascent i does not have powered woofer), than you might be lucky, but i don't suppose due to 2nd, 3rd,4th etc.. harmonics. So generally it is better to get as huge current and big wattage amp as money can buy not forgetting to audition as well. i know Sanders produce amps that says it would drive electrostatics well, but i haven't heard so i can't comment.

Ralph, you and I corresponded about the compatibility of my amp (ARC VS-115) and my fronts (Paradigm Sig. S-8s) a while ago. The S-8 is "nominally" rated as an 8 ohm speaker. However, as I recall, the impedance curve takes a dive at the 4 ohm level in the low bass register. But for the most part, the impedance curve looks like a roller coaster, but generally at much higher impedance levels.

I suspect that this is the case with many (maybe most?) speakers. So, what does that mean if one is driving their speakers with a tube amp and the impedance curve dips in the bass frequencies? Does that mean a tube amp will not be able to drive and control the woofers well?

I've not tried the combo and have not heard from anyone who has. However, looking at the specs you **may** have to use a set of ZEROs (http://www.zeroimpedance.com)to make it work as Martin Logans tend to have very low impedances at high frequencies.

But in general ESLs and OTLs do play well together! We have a number of customers that have Martin Logan with MA-1s are quite pleased with the combination, just none that are using the Ascent i.

Sorry, I meant MA-1 amps.