Starting to get interested in tubes

I have an ARC REF150SE driving my M-L CLXs.  Sounds amazing.

Don’t be stuck on preconceptions when it comes to tubes.  You will find the obvious increased naturalness, resolution, and transparency will make you reconsider your speakers.  Your tube amp choice will drive your speakers, and then you will start to think about different speakers.

I have a pair of 11a Impressions with Rogue Cronus Magnum III, the combo is So ridiculously perfect !!  Plenty of power in Triode mode and the sound is so 3D and smooth from top to bottom. Had a Nova300 before and sounded good, but nothing like this set up. Also the Phono in the Cronus 3 is stupid good with a Hana SL.

Yes, you can use an autoformer on each of the Manley mono blocs. This will solve the impedance matching problem.

If the Manley amps have an output impedance of 1 ohm or more they will not have a flat response into the varying impedance of an electrostat. They will instead follow an electrostat's impedance curve. 

The Manleys are rated at 250 watts@5 ohms according to their specs

agree with posters about amplifying Martin Logans. I used to own a pair and they require pretty hefty SS power.

Your Nova 300 is a better choice for use with electrostatic speakers than any tube amp! Why? Because all electrostats have a wild impedance curve that goes from high to low (1 ohm above 10 kHz). This is a brutal load for any tube amp. Add in the fact that tube amps tend to have relatively high output impedance and can't deliver much current to a complex load. If you must have a tube component just get a nice tube preamp instead!

This statement is problematic. ESLs traditionally have an impedance curve that varies over about 9:1 to 10:1 from the bass region to 20KHz. If a solid state amp is used (and if it behaves like most solid state amp, being that it acts as a voltage source) then you can see that it will be putting out way too much energy at high frequencies.

The reason for this is unlike box speakers, the impedance curve of an ESL does not follow the same rules of resonance such that the impedance curve is a map of the efficiency of the speaker. IOW, it takes the same amount of power at 100Hz to make a certain sound pressure level as it does at 7KHz, even though the impedance at those two frequencies will be quite different! The 'voltage driven' concept doesn't work so well with ESLs!

Martin-Logan has been trying to get around this problem by keeping their impedance low- starting at 4 ohms in the bass and going down to 0.5 ohms at 20KHz. Since most solid state amps struggle with impedances that low (and because the speaker cable becomes a significant variable with impedances like that) in a way they sort of tame the brightness.


But you can get a tube amp to drive impedances like that by using a set of ZEROs (www.zeroimpedance.com). By using a tube amp (of sufficient power) and a set of ZEROs you can tame that brightness in the Martin Logans and otherwise have the smoother sound for which tube amps are known.

Your Nova 300 is a better choice for use with electrostatic speakers than any tube amp! Why? Because all electrostats have a wild impedance curve that goes from high to low (1 ohm above 10 kHz). This is a brutal load for any tube amp. Add in the fact that tube amps tend to have relatively high output impedance and can't deliver much current to a complex load. If you must have a tube component just get a nice tube preamp instead!