Recommend a good tube power amp in the 100 wpc range for under $4k


Folks, 

 I am looking to bi-amp my Fyne F702 speakers, with a solid state amp for the low end and a tube amp for the mods and highs.  The Fynes are floor standing 2.5 way units with 93 db sensitivity and 100 wpc rms power handling capacity.  My preamp is a Rogue Audio RP-7, and my current solid state power amp is a Benchmark AHB2 at 100 wpc.  My goal is not so much more power but to put a tube amp on the middle and highs.  The Fynes have two sets of binding posts, one for lower frequencies and one for mids and highs.  I am looking to go active bi-amping with a Sublime Acoustic K231 Stereo 3-Way Active Crossover.

  In addition to an amplifier recommendation, what else do I need to consider?  For example, if I buy an amplifier with wattage output similar to the AHB2, what other factors do I need to consider?  Because I do NOT want to modify the speakers in any way, do I need to consider a gain control to match level differences resulting from other factors, such as impedance differences? Or, can I just hook up the crossover between the preamp and the two power amps and enjoy the music, which is what it is really all about anyhow?

 

Many thanks for any and all comments.

mike4597

Showing 4 responses by mike4597

Thanks for the input so far.  Yes, I am looking for a bit of that “tube magic.” Switching to a tube preamp has made the music seem so much more alive, with more depth, possibly due to hearing more harmonics from the various instruments.

I now understand that I do not need anywhere near 100 wpc for the mids and highs, that probably 30 to 40 watts will be more than sufficient in our roughly 13 x 20 x 8 living room, open on one side to the dining room.  A higher power tube amp would just give me power reserves I probably would never use; we like to listen at moderately loud levels—just beyond where the speakers “open up”—not very loud levels.

Someone commented that the crossover will handle gain matching between the two amplifiers, which was a major concern.  
 

One thing I do not understand is the need to remove or disconnect internal crossovers when using an active external crossover.  My speakers have two sets of binding posts, one for lower frequencies and one for mids and highs.  When a manufacturer builds a speaker this way, do they not bypass at least the crossover divides the lows from the mids and the highs?  (In the F702s, that would at 250 hz.). If not, what is the point of two sets of binding posts?  Thus, it would seem to me that if I set the active crossover at 250 hz I am simply duplicating the internal crossover point and sending just frequencies below 250 Hz to the woofer, which is what the internal crossover does; frequencies above that are directed into the “upper” binding posts, and it seems to me that I would want to retain the internal crossover dividing the mids and highs (1.7 kHz in this case)  because I am only bi-amping, not tri-amping.  OR, are we getting into the “magic” of crossovers with the possibility of some undesirable interaction between the internal crossover at 1.7 kHz and the active crossover?  Can someone explain.

As you can tell, I am new at this, and I greatly appreciate your advice.  My current system is far beyond what air replaced in the past year—Infinity Modulus satellites (the 1992 quality model with EMIT tweeter before Infinity went mass market) and a NAD C356BEE used as a preamp feeding into a McIntosh MC2125, of which for the latter I was the original owner.  I am looking at tubes for the upper end to see how much better I can make my system without spending gobs more money.

Many thanks, folks.  Good listening to all.

OK folks, you’ve convinced me to reconsider.  I do not want to modify the speakers,  so it appears—as is often the case I found in my nearly eight decades—that the simplest course of action is most often the best answer.  I will, once I convince the wife, opt for a single tube amp; if something convinces me that I don’t have enough power, which is most unlikely, I could always buy a second identical amplifier or go to monoblocs.  I know there are LOTS of options out there.   Given my satisfaction with my Rogue preamp, I am considering either the Rogue Stereo 100 or the Atlas Magnum III and also the McIntosh MC 275 MKII, but the Cary CAD120S MKII also has caught my eye.

 

Any recommendations in the roughly $5000 and under range would be most welcome.  I prefer new equipment, preferably not made in Mainland China, as I don’t like supporting totalitarian regimes engaging in nefarious activities.

 

And, once again, thanks to all for your comments.  They have been most helpful.

Mike

Anybody here had any experience with the Cary CAD-120S II?  I know their preamps get very good reviews, but there is very little on the web regarding this power amplifier.

First off, I want to thank everyone who commented and offered advice. I had no idea that there were so many different small manufacturers of such good and highly-recommended equipment.  With a bit more money, my choice would have been very perplexing.  As it is, I chose the Rogue Audio Stereo 100 Dark, based on personal recommendations, recommendations from here on Audiogon, and reading a number of reviews.  I also contacted Rogue Audio and talked with Nick at Rogue Audio, who explained the differences between the plain and Dark models of the Stereo 100, and also said that the large majority of the Stereo 100 have recently been the dark version.  Given my experience first with the RP-1 and now the RP-7 preamplifiers, I decided the Stereo 100 Dark would be it, given the moderate efficiency of the Fyne Audio F702 speakers (92 db) and the modest size of our living/listening room (12+ x ~22, with 8-foot ceilings.

  And I have NOT been disappointed, and, at even just first listening, I am far from disappointed.  The switch from the Benchmark AHB2–an excellent amplifier—is astounding.  The sounds is so much more “musical,” open, airy, “real.”  The music seems to have much more “presence.”  Listening first to some Moody Blues, Beethoven’s 6th Symphony—both on quality CDs, and then an LP of Lincoln Mayorga and a friends (Volume III), the highs are clear and distinct, separation and lateral location of instruments is distinct, mid-bass is very tight with no unexpected hangover.  Placement of instruments front-to-back also has great depth.   Having attended many live classical concerts, I am initially struck by the realism achieved by this amplifier/preamp combination, especially at moderately—not “crazy”—high levels.  This is going to take much more serious listening … which also will be incredibly enjoyable.