Tube Amp for Martin Logan Speakers

Hi Smurf, your Aerius-is are getting a little long in the tooth too. Maybe you could fix the Butler and then save up for a whole new setup? The new Martin Logans sound really nice.

People recommend the usual wide variety of tube and solid state amps for MLs. Some people swear by ss, others by tube. PrimaLuna make nice monoblock tube amps that many people feel work well with MLs. I don't know if they fit in your budget or have enough power for you, but they would be worth checking out.

Robert Deutsch reviewed the ML Montis hybrid for Stereophile and concluded that despite the .5 ohm impedance at 20khz, the speakers could be driven nicely by the McIntosh 275 on their 8 ohm taps and even by the PrimaLuna Prologue Premium integrated amp. He didn't like the matchup with his Audiopax model 88s though.

In spite of the impedance curve, I haven't heard of people having problems driving them and I haven't had that problem myself.

Or you could check the ML website. According to ML the hybrids can be driven by amps outputting between 20, yes 20, and 500 wpc.

Maximum power draw is 200 wpc.

Rather than argue theory, give them a listen, then you'll know what amps they make beautiful music with. You may be surprised.

I think that ML designed their current line to be used with either tube or ss amps, the choice being the user's.

Robert Deutsch spoke with Peter Soderberg of ML who told him that of the systems he has set up using tube amps, about half prefer the 4 ohm terminals and half prefer the 8 ohm terminals. So obviously ML approves of using tube amps with their speakers. And with a max recommended amp power of 500 wpc, they also approve of ss amps.

The measurements in the review show some roll off above 5000khz but we all know that a flat frequency response does not mean a good sounding speaker.

In my opinion, these speakers are not beasts to drive and I think you would agree if you listened to them.

Bifwynne and everyone else,

Thanks for your efforts to clear up the technical issues involved.

Someone should tell Martin Logan about all this. Those idiots are telling people that their speakers can be used with a wide variety of tube and solid state amps.

I was just giving you guys a hard time. That doesn't come through in print very well. We get too serious sometimes.

Of course not every amp can handle the job when you've got a speaker that has an impedance of .5 ohms at 20khz. But you don't need a lot of power to reproduce most musical content at 20khz either. The highest fundamental on a guitar is less than 1khz. Overtones are very important but don't need a lot of power to reproduce.

Robert Deutsch had no problem with the 40wpc Prologue Premium Integrated and the ML Montis.

Here is what Martin Logan says in the manual for their current hybrids:

What size amplifier should I use?

We recommend an amplifier with 100 to 200 watts
per channel for most applications. Probably less would
be adequate for our smaller hybrids or when used in
home theater where a subwoofer is employed. Our
hybrid designs will perform well with either a tube or
transistorized amplifier, and will reveal the sonic character of either type. However, it is important that the
amplifier be stable operating into varying impedance
loads: an ideally stable amplifier will typically be able
to deliver nearly twice its rated wattage into 4 Ohms
and should again increase into 2 Ohms.

And:

Could you suggest a list of suitable electronics and
cables that would be ideal for Martin Logan speakers?

The area of electronics and cable choice is probably
the most common type of question that we receive. It
is also the most subjective. We have repeatedly found
that brands that work well in one setup will drive
someone else nuts in another. We use many brands
with great success. Again, we have no favorites; we
use electronics and cables quite interchangeably. We
would suggest listening to a number of brands—and
above all else— trust your ears. Dealers are always the
best source for information when purchasing additional
audio equipment.

So, you don't want an SET but you shouldn't be too worried about that .5 impedance either. ML did not say the amp has to double wpc with each halving of impedance, not even close. I do not think that a company that has lasted as long as ML has in the high-end world could get away with advising customers to use amps that make their speakers sound bad.

So, We need to be aware of specs but Trust your ears and Enjoy your music!