Vantage with McIntosh or Rouge

[Robin]

McIntosh MC275 Mk VI ~ Tubed Amp. ~ True Class "A" ?

You'll need a preamp w/ the Mac 275 Mk V as well since it no longer has input level controls (in order to make room for REAL binding posts -- a big improvement!) Many CDP's and DAC's have remote volume control. Some are better (sonically) than others. Levinson and Wadia are the best IMO.

I'll say (again) no other tube amp I've heard with a difficult electrostatic load (as in CLS's!) performs with the effortlesness of the MC275. Must be that output transformer!

Neil,

The McIntosh MC275 Mk VI ~ is considered true Class "A" tubed amplifier correct?

 

[Robin]

Does "A" Weighted Mean ~ Class "A"

I have question.

In all of the information I have read, McIntosh MC275 Mk VI, owner manual, brouchure and reviews. They refer to the amplifier's design as "A" weighted, is that another way of saying the MC275 amplifier is Class "A" designed amp?

 

[jjqiv]

That could be....

In any case, I just read on TAS or Stereophile, I forgot which, just yesterday.... one of them had a review on the Rogue 90 amp and they also mentioned a slightly elevated noise floor.

Noise floor has nothing to do with noise per say. It is the ability of a system to produce sounds at very low levels. The db level where sound drops offs/starts. Critically important for natural sounding music at lower levels. A low noise floor allows you to hear the inner/fine details of the music.

 

[nsgarch]

Robin, we luv ya . . . . . .

I have question. In all of the information I have read, McIntosh MC275 Mk VI, owner manual, brouchure and reviews. They refer to the amplifier's design as "A" weighted, is that another way of saying the MC275 amplifier is Class "A" designed amp?

Sometimes you just blow my mind girl! Next time you will be sent to Google all by yourself !

<TABLE cellSpacing=0 cellPadding=10 width="100%" border=0><TBODY><TR vAlign=top align=left><TD>[FONT=Arial, Helvetica, sans-serif]dB(A): A-weighted decibels[/FONT]</TD><TD>[FONT=Arial, Helvetica, sans-serif]The ear is not as effective in hearing low frequency sounds as it is hearing high frequency sounds. That is, low frequency sounds of the same dB level are not heard as loud as high frequency sounds. The sound level meter replicates the human response of the ear by using an electronic filter which is called the "A" filter. A sound level measured with this filter switched on is denoted as dB(A). Practically all noise is measured using the A filter. The sound pressure level in dB(A) gives a close indication of the subjective loudness of the noise.[/FONT]</TD></TR></TBODY></TABLE>
So "A weighted" refers to the way something is measured, and not to some intrinsic property of the thing being measured.

I don't know where the MC275 fits in the A, AB, etc. amplifier classifications. It has a unique tube circuit invented by Mr. McIntosh hisself, I believe. And although the patents have long since expired (along with Mr. McIntosh) nobody else uses it (though I'll bet they'd like to!!) because only Mac is set up to manufacture the bifilar/trifilar output transformers required to implement this (Unity Gain) circuit, in which power is drawn from both sides of the power tube (plate and cathode,) not just the plate.

I know that this results in cooler operation, and I suspect it has something to do with the Mac tube amp's affinity for electostats (but my ears tell me it's true ! )

 

[Robin]

Thank You Very Much. . . . .

Neil,

Excellent! Finially..., you have explained what I have always wanted to understand regarding just what "A" weighted means. I appreciate your paitience and kind understanding. You are a true gentleman...

Thanks again.

 

[Niels]

I listened to the MacIntosh MC275 with the Martin Logan Vantages. The preamplifier (also with tubes) and the CD player was from Copland. There was no harsness and the control was fine. It did seem like the sound was a bit veiled though. I compared with the MC2275 and a solidstate amplifier from MacIntosh and they both seemed fine. I am not sure I could tell the difference between the two, they simply sounded fine and seemed to provide what was missing in the treble with the MC275. The MC2275 and the solidstate amplifier are too large, ugly and expensive though. I may check out the Pathos Logos amplifier instead if I can get a listen with the Vantages. I don't know if the problem with the listening experience was the preamplifier. Maybe another preamplifier could provide what was missing. I suspect, however, that the problem simply was that the MC275 simply was not able to run the Vantages.

 

[NicksPicks]

the vantage is 92db in room, I believe. you should be able to run those w/an SET amp. seriously.

the fisrt time I heard those (and I WILL own some), they were driven by a middle of the road cambridge audio integrated. blew me away.

your MAC will do the trick, and then some. Hell...you could even drop down in power to something in the 40-50w range and be dandy.

 

[nsgarch]

275 and Vantages

I listened to the MacIntosh MC275 with the Martin Logan Vantages. It did seem like the sound was a bit veiled though. I compared with the MC2275 and a solidstate amplifier from MacIntosh and they both seemed fine. I suspect, however, that the problem simply was that the MC275 simply was not able to run the Vantages.

That's ridiculous. I know two Vantage owners w/ MC275's and I run my CLS's full range with one, and we all love the incredible performance; albeit using better driver tubes (3) than Mac supplies. The MC275 is pretty impressive out of the box -- and it's sensational with decent tubes. I've no doubt there was something amiss with the setup you heard, and I don't mean the preamp or sources. For instance, did you make sure the Vantages were connected to the 4 ohm output taps? A common dealer mistake is to always use the 8 ohm taps with everything "to be safe." Perhaps the input level controls (if it was a Mk IV 275) were not turned all the way up. NEVER assume a dealer setup/demo is correct for the equipment you want to audition. The only two places where that's guaranteed are at the factory and in your home!!

I suggest you request a home demo and hook the amp up to your speakers yourself (ie properly.) And make sure all other connections/adjustments are correct. I guarantee you be able to stop doing this: :banghead:

 

[Niels]

The 4 Ohm tabs were used. The version was Mark V so there are no volumecontrols. To listen to the setup at home would be ideal especially if I was still able to compare all relevant amplifiers to each other. At this point however I am not sure that the MC275 has the sound I want.

 

[nsgarch]

The 4 Ohm tabs were used. The version was Mark V so there are no volumecontrols. To listen to the setup at home would be ideal especially if I was still able to compare all relevant amplifiers to each other. At this point however I am not sure that the MC275 has the sound I want.

Well Niels, before you inadvertantly "un-choose" one of the best amps ever for driving electrostats, you might want to read this just-out review from Steve Hoffman in Tone Magazine: http://www.tonepublications.com/TA-mag.htm in which he compares it favorably to his $50K Wavac (un-named, but that's the amp he apparently uses for mastering)

Additional pics and comments here: http://audiokarma.org/forums/showthread.php?t=108069

If Vantages were being driven full range (like the older MartinLogan hybrids, or Vistas), one might want two MC275's in mono; but the Vantages have their own SS amp for the woofers, so 90 watts/ch is plenty for the electostatic mid/high panels. Some people with Summits use two MC275's, but they have more money

 

[kach22i]

Not having hear the Vantages and only knowing what I've read I think either amp will work well.

That leaves things like connections which on the Mac I think are "balanced" and unbalanced (RCA) the Rogue both as well.

Which leaves looks, resale value and service.

The Mac is a looker, you can see the tubes.

http://www.mc275.com/

http://www.6moons.com/audioreviews/rogue2/m150.html

 

[DTB300]

Which leaves looks, resale value and service.

And the sound....

No matter how it looks, etc. if you do not like the sound signature of a particular component, then it is not for you, no matter how many people love it.

Dan

 

[Niels]

The review in Tone magazine is very convincing I must say. This is not, however, a question of whether the MC275 is a good amplifier or not. The problem is the very low impedance of the Vantages. This means a significant need for current not effect in the midrange and treble. Or to be specific an amplifier designed with a low outputimpedance, and preferbly constructed specifically for heavy loads. So the challenge is the combination not the individual components.

 

[nsgarch]

The review in Tone magazine is very convincing I must say. This is not, however, a question of whether the MC275 is a good amplifier or not. The problem is the very low impedance of the Vantages. This means a significant need for current not effect in the midrange and treble. Or to be specific an amplifier designed with a low outputimpedance, and preferbly constructed specifically for heavy loads. So the challenge is the combination not the individual components.

Niels, your concern about driving speakers w/ difficult impedance curves (ie electrostats ) is the very reason I chose the Mac. You see, it uses McIntosh's proprietary "Unity Gain" power circuit, in which power is drawn from both sides of the tube, the cathode and the plate. But this necessitates a special output transformer with two primary windings (bifilar) which only McIntosh makes (in house.) This arrangement makes the MC275 pretty much indifferent to speaker impedance nasties. The frequency response is very flat top to bottom.

Further, I was using my Levinson 23.5 interim (after selling my ARC's) to drive my CLS's. Now this is a hell of a musical SS amp. But I A-B'd it w/ the Mac, and (nobody believes this, but I swear on a stack of 180 gram vinyl) the Mac was both quieter and more detailed. I will say this, and Steve Hoffman alludes to it in his review -- and that's changing out the three 12AX7's to Telefunkens or RCA black/long plates catapults this amp into the stratosphere. Actually I posted a report of my experiences with tubes and the MC275 on Agon and on Audiokarma.

Neil

 

[paulo m]

If Vantages were being driven full range (like the older MartinLogan hybrids, or Vistas), one might want two MC275's in mono; but the Vantages have their own SS amp for the woofers, so 90 watts/ch is plenty for the electostatic mid/high panels. Some people with Summits use two MC275's, but they have more money

I had a brief audition of the MC2275 (an integrated MC275) with Vantages this weekend and it was certainly alluring (the MC275 is an amp I am considering to replace my Pathos Logos, but they didn't have one set up). When I asked about the current/power needs of MLs, the salesman indicated the MC275 might just not be enough, depending on the type of music you listen to. I inquired about the use of two MC275s and even though he confirmed it was a possibility, he suggested an audition with either the 402 or the 602 power amps. Now, these are SS, and I strongly doubt they would sound as good as the 275, but it sort of confirms the ballpark power these speakers like to see. I think the idea of using two 275s is crazy at all and I will make this comparison sometime in the next couple of weeks (i.e. a 402 vs a 602 vs two 275s).

 

[paulo m]

The review in Tone magazine is very convincing I must say. This is not, however, a question of whether the MC275 is a good amplifier or not. The problem is the very low impedance of the Vantages. This means a significant need for current not effect in the midrange and treble. Or to be specific an amplifier designed with a low outputimpedance, and preferbly constructed specifically for heavy loads. So the challenge is the combination not the individual components.

The better McIntosh amps all use their own variant of autoformers, which ensures enough reserves of current even for the most demanding speakers. This is just like the zero impedance autoformers you can buy separately to turn your speakers into an easy load. In any case, it is generally accepted that MLs like lots of power and as I mentioned in another message, the MC275 might not be enough--I still have to confirm this with my ears, though, and I hope I can do it soon as I am also looking into getting one (or a pair) for my Vantages. Of course, the issue then will be which preamp to choose...

 

[nsgarch]

Mac SS vs. Tube

The better McIntosh amps all use their own variant of autoformers, which ensures enough reserves of current even for the most demanding speakers. This is just like the zero impedance autoformers you can buy separately to turn your speakers into an easy load. In any case, it is generally accepted that MLs like lots of power and as I mentioned in another message, the MC275 might not be enough--I still have to confirm this with my ears, though, and I hope I can do it soon as I am also looking into getting one (or a pair) for my Vantages. Of course, the issue then will be which preamp to choose...

Paulo, let me just clear something up: the Mac SS amps use autoformers, their tube amps do not. They use the autoformers so their SS amps will deliver constant power (in Watts) no matter what the speaker load (impedance.) I don't know why they think this is a good thing, but a price is paid in reduced damping, which is a big reason many people buy SS amps in the first place

Their Unity Gain (tube) circuit combined with their unique bifilar wound output transformer, handles stats with no problem; as a byproduct, it also makes for a very cool-running amp (for a tube amp.) And can you imagine, 90 watts per channel out of just two KT88 power tubes per side!

I know two Vantage owners (1 has MC275 and 1 has MC2102) and they have no power problems whatsoever. I have an MC275 driving my CLS's, which have the same power requirement as the Vantage. Stats need current, not watts, as their impedance drops. And this is where some amps just fall apart. With Vantages, Summits, (or CLS's with a sub) the owner's amp doesn't need to do bass duties, so power and damping factor are less of an issue. Sonics are more important, and tubes and stats are the magic combo. SS amps (without autoformers please) are for woofers. I suggest you get just one MC275 and use it for awhile. You can always get another, but I bet you don't

 

[paulo m]

Paulo, let me just clear something up: the Mac SS amps use autoformers, their tube amps do not.

You are, of course absolutely correct. I think I just equated the unity coupled transformers in the tube amps with the autoformers of their SS line. Thanks for the correction. In any case, the proof will be in the listening, and I really couldn't care less what goes inside the unit .

 

[Shoe]

Does The Mc 275 IV have enough current/power?

Does the Mc 275 have enough current/power?

I can’t believe that the issue regarding the Mc 275 having enough power to run the Vantage is still being called into question. Neil knows what he talking about. I have talk to him on the land line and have corresponded with him quite frequently. He knows his stuff- Having said that, I have the Mc 275/ Vantage set up in a two channel set up in 13’x 30’ dedicated room ( see system #184) that is somewhat deaden by bass traps and absorption panels. The Mc plays almost as loud as the CJ 2500 (250 watts solid state) but with greater musical involvement, deeper and wider soundstage. More importantly there is incredible coherence of the musical presentation that I have ever experience with this current setup. I have been in audio for over thirty years, even though I am limited in articulating what I am hearing, to my ears the Mc 275 / Vantage is by far the most satisfying system I have ever own or heard . Does the Mc have enough power? Absolutely! Could the Mc 275 be consider a musical amp? No question. You must go an audition it, I think you will be amaze. The icing on the cake is tube rolling, but that’s Neal department. Sam,

 

[Niels]

It may be right that the McIntosh MC275 has enough current capacity and sufficiently low outputimpedance to run the Vantages. I may even go back to the store to have another listen with another set of preamp/CD-player to run the setup. In my experience it seemed however that the integrated MC2275 was less "veiled" in lack of a better word. I noticed that the MC2275 has 2, 4 an 8 ohm outputs, while the MC275 has 4, 8 and 16 ohm outputs, so the MC2275 is not simply an integrated version of MC275. The veil seemed to disappear on the integrated MC2275, however, using the 4 ohm tabs on both amplifiers and anyway, I am not sure I would be able to hear the difference between the tabs.

I am also considering the Pathos Logos, any experinces on what this sounds like in comparison with the MC275? Why are you considering to get rid of your Logos, Paulo?