Right amp for the Montis

Dave, I am using a pair of Naquadria Audio Fireblades. They're a mono bloc design using 4 x 6550 tubes per amplifier which are run at 55%, rather than the 100% than most other tube amps.

After listening closely again, you're right about the mid range - it's superb. The upper frequencies are smooth as, but a little bit rolled off compared to my old Bryston B-60. But the low frequency response is so much more organic than the Bryston. I guess you're right. Sizzling treble is not why we love tubes. It's all about that magical mid range.

Everyone I'd talked to told me that Stats power requirements were pretty high. Much higher than my M40s. Is this not the case? What kind of power requirements should I be taking into consideration when purchasing an amp?

I think thats probably a question a lot of us new guys probably have. Not so much "which amp", but how do I pick one? I know I want double the power at 4 ohms than I get an 8 ohms, but what kinda wattage should I be looking at? ML says I should give anywhere from 20-300 watts/channel, but that seems really broad. I'm currently giving about 75 watts/channel with bi-amping, but I've been window shopping at Rotel amps such as the RB-1582 or RB-1572.

Further the other question that comes into play is amplifier types. Class AB is more efficient so is that typically the way to go?

My Bryston amp does a more than adequate job with my Montis .


J

I listened to an Audio Research system at their Dallas dealer recently, and I really loved the new AR SP20 tube preamplifier with the AR DS (definition series) solid state amp. I'm leaning toward buying the AR SP20 and AR DS450 after hearing the combination. I think ESL speakers benefit from a high current amp. I'll buy the Montis and the preamp and amp soon and report back. Thanks for the all the recommendations and benefits from your experiences.

Hi I am getting an Audio Research Ref 110 for a power amp, with tubes upgraded to KT120 (which are the ones for the new Ref 75). However if you haven't bought already, after demoing some amps, all I will say is that audition more, see if you find something you like more (if you don't you can always buy AR). I tried Krell and Levinson in my system before buying AR. Also tried Conrad Johnson, GamuT (which si strongly recommend), and Bel Canto. Canto is the other amp I considered because it has a different sound from the others above. Best thing you owe yourself is to try different sounds before buying

Hi Silvercat,

I wanted to mention that I am a longtime Anthem fan, having gone through 3 generations of their preamp-processors. I am driving my Montis' via an Anthem AVM50/3D preamp-processor and MCA-30 power amp, which also powers my center channel speaker for home theater....i love the sound, but once my wallet recovers from the Montis purchase(got them last March and still feeling the burn !), I want to look at some tube options such as the AR pieces. I am also an avid headphone user and would not consider anything other than tube amps to drive those, so I want to find out how the Montis likes them as well. Good luck!

Jeff

bonzo,

I agree with you that the more auditions, the better. However, if those are auditions in a dealer's showroom, they can only give you a glimpse as to what it will sound like in your home, your other equipment, your music at your volume level, etc.

As we all know, an in home / return option audition is the bomb proof way to go.

GG

Response of Spires with My Carver VTA305M tube-based monoblocks.

I have the Carver 305W Monoblocks (Cherry VTA305) with a stated output impedance of 1.6 ohms driving my Spires which use the same panel as the Montis. I plotted the frequency response of my room and noticed a 10dB slope off starting from about 3kHz all the way down to 15kHz. Ignore the sharp roll off after that as it could be due to the mic.

Anyways, I had Bob carver mod the amps via a feedback option switch where I switch in the normal mode and his mod (See spires mode attachment). You can see that the roll off has been mitigated.

ML sent me this info about the spires panel impedance:

20kHz – 0.80ohms
15kHz – 1.27 ohms
10kHz – 1.68 ohms

So at 10K, you loose half your tube amplifier power(as the output power transformer has a 1.7ohm impedance like I said before) and more so after that. The drop of is very audible and to the un-suspecting ear, you hear it as a softness in the highs. This only happens when driving X-stats. Standard cone designs do not have this behavior.

PS
Although the standard carvers use the KT120 tubes, I had Bob design in the newer and more powerful KT150 power tubes. Sounds awesome and powerful.

dmusoke said:

I have the Carver 305W Monoblocks (Cherry VTA305) with a stated output impedance of 1.6 ohms driving my Spires which use the same panel as the Montis. I plotted the frequency response of my room and noticed a 10dB slope off starting from about 3kHz all the way down to 15kHz. Ignore the sharp roll off after that as it could be due to the mic.

Anyways, I had Bob carver mod the amps via a feedback option switch where I switch in the normal mode and his mod (See spires mode attachment). You can see that the roll off has been mitigated.

ML sent me this info about the spires panel impedance:

20kHz – 0.80ohms
15kHz – 1.27 ohms
10kHz – 1.68 ohms

So at 10K, you loose half your tube amplifier power(as the output power transformer has a 1.7ohm impedance like I said before) and more so after that. The drop of is very audible and to the un-suspecting ear, you hear it as a softness in the highs. This only happens when driving X-stats. Standard cone designs do not have this behavior.

PS
Although the standard carvers use the KT120 tubes, I had Bob design in the newer and more powerful KT150 power tubes. Sounds awesome and powerful.

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Is this measured from spot or close proximity of element? Generally slight roll off towards highs is preferred for room response.

MPS said:

Is this measured from spot or close proximity of element? Generally slight roll off towards highs is preferred for room response.

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Sorry for the late response .... This response was taken from the major listening position, about 13 feet away from the speaker.

bonzo said:

One I ruled out after multiple tries is Devialet

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Hi bonzo, If I may, why did you rule out Devialet?

thanks

amabrok said:

Hi bonzo, If I may, why did you rule out Devialet?

thanks

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Poor in soundstage, bass, midrange, and separation

thanks for the quick response!

which Devialet you auditioned?

amabrok said:

thanks for the quick response!

which Devialet you auditioned?

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240 with the summit x and 170 with em esl. Also the premier with avalon

bonzo said:

240 with the summit x and 170 with em esl. Also the premier with avalon

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interesting!

I currently drive my Montis with D400 (in dual mono configuration) and i have to say it is really great. Maybe a little bit bright on the highs but i believe most of it is due to room acoustics and placement.

However i am also intrigued to try Sanders Magteck or ESL Mark II ...

thought?

What have you compared it with? A guy named Matt in London kept saying the Dev was great with his montis till he heard the Sanders, and now likes the later more. And he hasn't heard other stuff, I think, like valves, etc on his

amabrok said:

I currently drive my Montis with D400 (in dual mono configuration) and i have to say it is really great. Maybe a little bit bright on the highs but i believe most of it is due to room acoustics and placement.

thought?

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seeing your room / speaker placement there is NO question as to the 'brightness'. Without treatments, etc the only way to curb some high freq 'sting' would be with warm tube amplification ……………. I'd recommend getting your listening environment squared away first.

bonzo said:

What have you compared it with? A guy named Matt in London kept saying the Dev was great with his montis till he heard the Sanders, and now likes the later more. And he hasn't heard other stuff, I think, like valves, etc on his

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I compared it with McIntosh MC275 and Parasound Halo JC1 and A21

Also a while ago i auditioned them with Primaluna but can't remember exactly which model was that

amabrok said:

I compared it with McIntosh MC275 and Parasound Halo JC1 and A21

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Mine were with krell, AR, and levinson. Unless you want a one box clean looking system, I.would suggest buying a used source, pre, and power separately