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Tube Amp for Martin Logan Speakers

Hi, I love tube sound through my Martin Logan Aerius-i fronts and Cinema-i center. I currently have a Butler 5150 which is a hybrid, but it busted on me and would cost $700 to fix. I've had china stereo tube amps that were pretty good and gave true tube sound, but not enough drive for higher volumes. I live in condo, so not like I can blast music anyways but still. I got the Butler because I wanted 5 channel tube sound for home theatre (The piercing sound from my Denon 3801 receiver was not pleasant to my ears). It appears there are only three multi-channel tube amps around, from Mcintosh, Butler 5150, and Dared DV-6C. The latter two are hybrids, and the last one was one of the worst tube amps i've ever heard. I have no clue why 6Moons gave the Dared a 2010 award, but maybe it's because it produces only 65W.

So since multichannel tube amps are hard to come by, and they tend to be hybrid, I was thinking maybe it would be best to get three true tube monoblocks to power my fronts. Thing is I wonder if they will be underpowered for my speakers, and not sure which ones are decent for the price. Maybe China made ones would suffice, and they still go for pretty expensive price. I'm wondering if anybody knows of a decent powerful tube monoblock that is affordable, because I can't pay $3000 per block. or maybe best to just repair my Butler. Thing is, I'm not confident that it is reliable. The tubes are soldered in which is weird, and i've taken it to a couple repair guys who both said that the design is not good, because it's very tight inside and more susceptible to being fried from DC voltage areas. it's too sensitive.

Any suggestions for tube monoblocks, even if china made ones? the holy grail for me would be Mcintosh tube amp, but they are hard to come by. Thanks.

smurfmand70
atmasphere's avatar
atmasphere
7,068 posts
 
George, you took the quote out of context- sounds like you didn't read the article to me.

Unsound, I have a number of friends in the industry that make transistor amps. When Steve's letter turned up, I asked them about this and their response (paraphrasing) was:
'Just because the amp can drive a lower impedance with more power is not the same as saying it is also sounding its best.'

Now there is no argument that supports your position that because the impedance of the load is lower, that this translates to
extend frequency response, improve the linearity of frequency response, and as you've already noted can increase dynamic range.

Of the latter point 'dynamic range' you are putting words in my mouth.

But given your response (and apparently also that of George) it does indeed appear that the both of you prefer to have your amplifier add some distortion. So in that regard we do indeed differ- I prefer a lack of distortion if possible.
mapman's avatar
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mapman
15,679 posts
 
I'll agree that benign speaker impedance curves makes it easier to find an amp that is likely to sound really good with said speakers.

But lower and more challenging impedance curves are more the norm these days, and with just a little care, one can find many amps that are good matches. Class D amp technology pushes this truth even further than before, and makes smaller more efficient packages that perform well possible.

SO choose your approach wisely and listen to the results and there are multiple paths to happiness.

There are always so many types of distortion at play in any reproduction, that focusing on any particular type does not tell the whole story nor add much value IMHO.
smurfmand70 OP
10 posts
 
Wow I want to thanks all who have responded, much appreciated. It looks like monoblocks are too expensive and means id have to power each one on manually. I know you can get some unit to power things on but I'd like to have the simplest solution with acceptable warm flat sound. A good solution might be to get stereo tube amp for the fronts and just use my denon for centre and rears. Just wish there were more multichannel tube amps, because then the sound from 5.1 would be more even between the speakers but I guess it would be too massive in size and not as reliable.

I spoke to a reputable amp repair guy I'm my area and he says that warm sound can be had from SS by maybe replacing some parts. Says that tube amps are not reliable as most have to be hybrid in order to dish out a lot of power. I'm not very technical in this aspect. All I know is that with my denon 3801 with about 150w or so at 4ohm and listening to Chris botti 5.1, when Yo Yo Ma begins playing, the cello doesn't sound as deep and full as when I was using the butler 5150 with 225w. With the Dared multichannel hybrid at 65w per channel. it was even worse. The repair guy suggested get affordable parasound SS and make some relatively cheap mods, as he says the design is decent and easier to repair than other brands.
smurfmand70 OP
10 posts
 
I could repair the butler locally and add sockets for the tubes for easier maintenance. I'm just not too confident in its reliability. Seems that it's very sensitive and can blow if moving it around or playing with cables. The other option is send back to butler so they fix back to original spec but that would probably cost more than 700. a lot cheaper than getting monoblocks, and about same price as getting a used SS amp.

I've read that martin logan have demo'd their speakers with parasound which apparently has warmer sound as opposed to say lexicon and nad amps, so maybe should look into that.
smurfmand70 OP
10 posts
 
Im shocked at how much tube monoblocks go for new. I don't get how it is justified for makers to charge 3000-10000 for such a small thing. Compared to SS amps that are massive and with more parts. I guess tube monoblocks have solid gold power sections or something.
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