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Using tube amp with electrostatic speakers.

Moons ago I started similar discussions and thought I had been given enough good advice not to approach the subject again. Here goes anyway. I've used Martin Logan electrostats for well over 30 years with quite a few different amps but have recently switched to a tube amp and dynamic speakers with which I am very satisfied.  It consists of the Cary Rocket 88R amp and Serie Reference 3 speakers. 

My brother was visiting last week and was so impressed with the sound that he decided that he might want to try a tube amp also (probably the same one as mine).  However, he is using a pair of SL3's that I gave him years ago and I'm concerned primarily about the current requirements of the Martin Logans as well as other concerns that I'm not thinking of.  I don't want him spending money on something that may not bring him improved sound so would appreciate more advice to pass on to him.  He currently uses a Rogue Audio SS amp with his SL3 speakers and, to me, it sounds very good. 
jimbreit
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rauliruegas
13,050 posts
 

Dear  @milt808  : " a warmer sound with more harmonics. "

 

First the harmonics are developed by the recording source we are listening it and those harmonics have changes through all the signal path where that signal must travels in our room/system till goes in our ears/brain/body. A good room treatment and fine tunning the subwoofers SPLs can help for that warmer sound  you are looking for that again depends on the signal source. The issue is not about tube amplifier because your speakers impedance at a critical 20khz frequency is down to 0.43 ohms and I don't know yet a tube amp that can handled with applomb that speaker impedance.

In my opinion this is the amp for your system and I think you can't go wrong with:

 

https://parasound.com/jc1+.php

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

lewm
13,017 posts
 

Unless Martin Logan  says otherwise, I would assume that they have not abandoned their stated policy of designing their speakers to accommodate solid-state amplification best of all. That really means the speakers are likely to have a low nominal impedance. You might check this out with Martin Logan. If I am correct, then you may be best off with a solid-state amplifier, but there certainly is no harm in trying those BAT amplifiers, if you have them on hand. If Raul is correct about the impedance at 20 kHz, that squeaky low impedance could be vexatious for any amplifier, solid-state or tube type. However, the saving grace is that very little amplifier power is needed at such very high frequencies.

lewm
13,017 posts
 

I see now in the advert that the nominal impedance is 4 ohms, going down to 0.43 ohms at 20kHz, per Raul's statement too.  That's not a great situation for any sort of tube amplifier, but it could be made to work I guess.  Using Autoformers from Anti-Cables would help.

atmasphere's avatar
atmasphere
11,793 posts
 

That's not a great situation for any sort of tube amplifier, but it could be made to work I guess.  Using Autoformers from Anti-Cables would help.

I can confirm that is the case. Once the impedance issue is corrected, the MLs are really fairly efficient; 100 Watts is plenty of power.

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