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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
almarg's avatar
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almarg
9,670 posts
 
George, where do you see an indication of a MEASURED damping factor of 4.7?

Regards,
-- Al
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georgehifi
10,312 posts
 
From here Al. At the The Manley website.

http://www.manley.com/msn.php

Features and Specifications
Manley Snapper

Damping Factor: 4.7

Cheers George
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almarg
9,670 posts
 
George, the 4.7 number appearing on that page is a specification, not a measurement. On the same Manley page an output impedance of 1.5 ohms is specified, which is confirmed by TJN's measurements in the review you linked to. On the same Manley page, and also in the manual, the statement "optimized for 5 ohms" appears. Maximum output power, input sensitivity, and frequency response are all specified for a 5 ohm load. The 5 ohm power rating is higher than the 8 ohm power rating, for the same distortion level.

I see no reason to assume that the 4.7 number is accurate and the 5 ohm number is not. As I said, the converse seems much more likely.

Regards,
-- Al
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georgehifi
10,312 posts
 
All depends on which way you look at it Al.
Saying it's "optimised" for a 5ohm speaker does not mean it's a 5ohm tap.
But giving figures as exact as in 1/10th's, 4.7 for damping and 1.5ohm for output to me is far more exacting.
And from these two figures the tap is closer to an 8ohm tap than 4ohms.
Whatever the case, the way your seeing it, or me, it's not the ideal amp for what the OP has.

Cheers George
tradeontheweb
43 posts
 
Atmasphere. I have indeed used the Zero's on many occasions, as I mentioned in my post. So my opinion IS based on experience, not on any wish to derail this thread, as you insinuate. My experience with them was as I indicated - yes, they allow amps that would otherwise struggle, to drive speakers that present too hard a load for them. An analogy would be saying that your standard 4 cylinder commuter car is capable of 200+mph. But only when towed by a Nascar ! Then claiming that there's no difference in the experience vs not being towed. By their very nature, the Zero's must add/subtract something from the sound. I'm sure their are many happy Zero owners out there. There must be, as they sell. But, I suspect those owners would be better off educating themselves, then spending the money on a better matching between components in the first place. I have yet to hear a system that benefitted (sound-wise) from their use. Your assertion that they "solve a problem" is correct, technically. But at the cost of sound quality. If sound quality is not a priority, then sure, buyers have indeed got their mismatched components to "work" together. But only that. The degradation of sound quality is obviously secondary to them. As a manufacturer, I would have thought your emphasis would be on making sure your amplifiers were matched with speakers that show them at their best ? Surely you're doing your products a disservice, by suggesting the Zero's as a bandaid panacea for buyers ? Just my 2c worth !
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