Martin Logans and SET? Am i nuts?

BearcatSandor

BearcatSandor

New Member
Am i nuts? Probably, but it looks like i may have some company 'round here as far as audio stuff goes.

I had a Carver TFM-55x and a pair of BP-2002 speakers. I enjoyed them but i have always been looking to upgrade them. Fate dealt me a rough hand when my home burned and i lost that system *cries for a bit*

I bought that system about 8 years ago and i have leaned a lot since then. Since then i have discovered planar speakers (martins, sound labs and maggies) and tube amps.

I love the sound of tube amps and electrostatics. I got to hear the Sound Lab M1s and the atma-sphere tube amps (Waaay more then i can afford!) and they absolutely blew me away!

A new hi-fi store opened near me (near is relative out here). I was there for hours recently and had the mind-opening experiance of how close you could get to the massively expensive systems with systems costing about 10 grand or half that.

So i want to replace my system. I have some little speakers i can hook up for the time being, but i need to get an amplifier. I am looking at tube amps.

It is my understanding that a SET will sound better then a p/p tube system. So i started looking at SET amps.

Now eventually i want to end up with electrostatics. I'll probably want the Martin Logan Summits or the Vantages, or some other speaker with a Martin Logan sub (but i'll focus on the other two for now).

If i end up getting a SET amp that has, say about 10-15 watts can i run the Summits with their 92 db sensitivity? What will happen to the Summits and what will i hear with a low powered amp? If i go to a Art Audo SET px-25 with 6 watts what then?

I listen to all kinds of music from metal to classical to electronic to blues. However, i don't listen at loud levels and have a small room. I am more interested in a holographic presentation then volume.

I recently read about Butler Amps and the Dared amps. I'm not sure i like the idea of the hybrid Butlers with their tubes soldered into the boards. I have read that the Dared aren't built as well as say the Carys or the Art Audio's but we are talking about different price points here.

I use a computer (with digital outs) as my front end, so this product has perked my ears:
http://www.6moons.com/industryfeatures/dared/dared.html
I could just hook it up to my usb port and go and it's only $550 bux!

How does it sound? I don't know as it's not out yet.

However, could i drive a pair of Martin Logan Summits or another electrostatic with a < 90db rating with a 14 watt amp?

By the way, i don't know what they mean by "hybrid" on that page. I'm still investigating. I also don't know that those tubes are going to be good enough *sigh*.

Thoughts and opinons?

Thanks folks
 
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with 92db sens and a fairly flat impeadence 10-15 should be fine but may need a little
help in the bottem end by x'ing them over at say 100hz but 6 watts would be pushing it!

I wouldn't go below say 92db on the speakers with about 12watts of power. I have a
300B at around 11 watts of power and it does run out of steam on speakers of 90db or less!
 
Well, you see the impedance on the Martins is *not* flat. It goes from 4 to 0.7 ohms. It's good to hear i can get away with such low wattage, but am i going to wear out my tubes quickly?

The Summits x-over at 270hz to the powered woofers and the Vantage x-over to the powered woofers at 400hz so that should be fine, eh?

Again, i'm not planning on running these at "concert levels" or reference thx levels. Both of those are waaay too loud for me. I wear ear plugs loosely at movies these days. I swear the world must be going deaf!
 
Low wattage ecspecialy in tubes does NOT like low impeadance! Nor do they like large
impeadance swings "no tube amp really" so now I'm not sure and will step back to
let others more qualified then I to comment.

Most of the speakers in the catagory of what your looking at have an almost linear
impedance curve so a tube amp that has enough to just drive them usually works good.

But if it was me I would not use a low powered or maybe any tube amp on a speaker
that the amp had to deal with a .7 ohm load!

It would do nothing to wearing out the tubes though as tubes run wide open all the time
regardless of what they are doing so no extra wear happens.

Again others may have better and more info than I, sorry!
 
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Yep, you're nuts. Martin-Logans are notoriously hard to drive, and SET amps have notoriously inaccurate frequency response. Combine the two and you'll get sound, it just won't be an accurate reproduction of the input signal. If you prefer random tone generating devices over musical accuracy you may be happy. If you'd prefer your system replicate what musicians sound like live in your living room then you'll want an amplifier that is stable into a constantly changing load.

My wife and I had a pair of Martin-Logan ReQuests when we lived in California, with an Adcom GFP-565 preamp and Adcom 200 wpc monoblocks driving them. We liked the combination, and believed it was musically accurate. Our confirmation came when a friend visited and we popped her CD into our Rotel RCD-965, then had her stand in the middle of the speakers and sing along with her CD. Her voice out of the speakers matched her voice live. Even her boyfriend was impressed.

One singer plus acoustic guitar is a pretty easy load to drive, and I'm not trying to convince anyone that Adcom is the best gear for pushing Martin-Logans, but an SET? You'll find yourself listening to distortion and varying output waveforms rather than music. I prefer my musical reproduction accurate, and having the singer blend with the recording while she's standing in between the speakers is a pretty damn good test. The only tube gear I've heard do justice to Martin-Logans is Audio Research. Anything less and you're better off with good solid state amplification.

I will now duck and run while the bottleheads take shots at me. :para:

Before you lock and load, answer this: How many times have you had live music in your living room? :uzi:
 
Photobitstream,

That's great to know. Would the same problems exist with a push-pull tube amp?

I've also been considering a hybrid, like the link i posted above or a good class D amp like the Nuforce reference 9s.

If i went with the hybrid 14 watt above (http://www.tyger.org/efbc/2000-4-29/pabloface.jpg), would you expect the same problems as a SET? I'm new to tubes can you all tell? I apologize for my tube-newbie-ness.
 
I'll leave it to other people to give you advice on stable tube amps. As I mentioned, the only tube amps I've heard that can drive MLs accurately are the AR amps. I'm sure there are others out there, I am just not familiar with them. Wardsweb has some Martin Logans. Maybe he'll chime in with a recommendation.

I prefer solid state amps for their reliability, and also because it is easier to design a good SS amp than a good tube amp, and therefore the price/performance ratio is better. I'd rather spend my money on the source than the reproduction, and sometimes the source is musicians in my living room. Or a friend's living room. I listen to a lot of live music.

Martin Logans are excellent speakers, and deserve excellent amplification. SETs are fine for highly efficient, stable speakers. Martin Logans are neither. They need a lot of power, and they need an amplifier that is stable into a low-impedence load. Unless you're willing to spend the money on Audio Research or similar gear you're better off looking at good solid state amps.
 
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"Martin Logans and SET? Am i nuts?" ...Yes!

Even if the ML's are 92db eff. which I kinda doubt, a low and widely varying impedance is NOT a good mix for tubes, especially SET.

In my experience, single ended triode amps can sound incredible BUT the speaker/amp mix is dead critical, make-or-break stuff and the wrong speaker with a simple no negative feedback SET amp will sound horrible.

Sure, real efficiency (as apposed to what some spec sheets say) is important but impedance is the big thing with SET. It might be worth mentioning as well that that the term 'SET' can be used differently by some - for me, it's a single ended directly heated triode amp and these are very low power until getting into the exotic high-voltage transmitter tube varieties. SET's would be a 45 (1.5w), 2A3 (3w), 300B (maybe 6w) but you won't get into the 10-15w range until using things like 211 or 845's.

I think tubes can work with ML's and I have heard and really liked the combination in the past but it was the type of amps Photobitstream referred to previously - high power push-pull with negative feedback as found from Audio Research, Conrad-Johnson, VTL, etc.
 
Yes after seeing what the load is on those speakers and the posts from photobitstream
I would tend to agree a nice big solid state would be more practical and work the best.

Unless you want to spend some big bucks on a large tube amp.

"notice the first line of my second post has been fixed" Forgot the NOT!
 
very cool folks. This was the kind of information i was looking for.

Does anyone feel that a hybrid amp would work well? (can you tell I really like the idea of the one above?). Does the small 14 watts make a difference in the stability?
 
Generally for low impeadence speakers (AKA hard to drive) you need AMPS, HIGH CURRENT!

A low power amp with not have the current it takes to power the speaker correctly!
I would say look for something in the 150WPC or above catagory to get good current.
 
Why not biamp? Use a fine solid state for the low end and a non-SET tube amp for the rest. Maybe this would resolve both your Martin Logan fix and the tube amp itch that you have............
 
A good portion of the tube sound comes from a tube preamp. If you are set on the Martin Logans which are hard to drive then maybe you should consider some high power s/s amps (150 wpc + sounds like good advice) and a nice tube pre to push it. There are lots of tube preamps to consider but at least take a look at Juicy Music. The reviews from real people (not critics paid to like everything) are great.
Another thought - have you listened to a nice tube amp pushing some good horn high efficiency speakers? Everybody's taste is different but if you try it you may like it.
 
No actually, i've never tried a horn speaker system. It's one of the things i am interested in, but the ones i have seen advertised (they look like a tuba horn with a smaller one underneath and have no box. They are a brand that sound come readily to mind, but don't) are *very* expensive.

I am pretty stuck on the sound of MLs though having been in love with the panel sound since i heard them. I have listened to the Logans, the Magneplanar and the Sound Labs. I want to listen to other speakers that can approach the same "you are there" holography air and detail but i haven't found any yet. The closest i have found were the Meridian DSP6000 but i found them fatiguing and expensive.

My madness might be better explained by the following:

The problem i am facing is that since my hi-fi system burned up, i have no working amp. I do have a pair of little book shelf speakers that with be some-what adequate. I plan on buying a pair of Vantages or Summits in the next few years.

I don't want to go out and buy an expensive band-aid just to replace it when i get the new speakers in a year or so. In effect i am looking at it as if i were building a system slowly.

One of my difficulties is that i don't have some of the listening opportunities some of you have as i am in a rural area. However, i *do* have a hi-fi store within 55 miles of me (it's the only one with in 200 miles or so). I like the folks there and have spend hours listening during their "Hang out, bring your discs at our listening party every two weeks" events

So, what I plan to do is to get a loan on, or purchase some of these products and bring them to the store and listen to the Summits or Vantages with them. If they sound really good to me (I know what i am looking for) keep them. IF not send them back and pay the re-stocking fee. The restocking fee is less then the travel required in auditioning some of these things.

But i'm asking all these questions so i know where to start. There is no point in my sending away for an Art Audio Px-25 (for instance *drool*) if it will sound bad on the MLs.

Thanks all.
 
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To find out if you can biamp these you need to get the impeadance factors for both
the panels and the subs.

And by all means if the bass cabinets are where these low impeadences come from and
these huge swings/tough to drive are at then yah maybe you can biamp with tubes on
top with a big solid state doing bass duty.

Those bottoms aren't powered allready from the factory? So the impeadence we are
seeing is just the panels?
 
That's what I thought, so yes that impeadence and tough to drive load is for the panels
themselves so a high powered amp is still needed and no biamping to be done here.
 
I was just reading a book last night that showed a schematic for a high-current 3W SET, designed for driving electrostatics. The problem, of course, is that it's theoretical, and that you'd have to build it yourself. If that's not an issue, I can post the schematic and relevant backgrounder and technical info. But I'm afraid if you want to drive a pair of M-Ls with a pair of VTL Tiny Triodes, for example, you're barking up the wrong tree, as so many others have so eloquently stated above.
 
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