I've never had good luck with JBLs and tubes. I have a pair of 4430s driven by an Audio Research Ref 110. Great speakers, great amp but the low end is either too loose or undefined. With a VT100 it was too thin. I worked for a guy who used MAC 275s on all kinds of JBL monitors and they were always clipping. I always figured it was the woofer tuning. These speakers have always worked great with a big solid MOSFET amp (Adcom GFA 5802).
Tubes and Altecs are a great combo from my experience. Get an ST70 and some Model 19s and you're done. Bigger tube amps are even better.
I'd like to know what happens if you get the Carvers. It's definitely a synergy thing.
Hey d2girls, it is grandpa D ( lol ). Are you currently running the Hornshoppe with a ss amp at this time ? I know you had most recently the Pass gear, and then the Kinky. Tubes are great with horns, but ime, they do trade off certain characteristics, that " I find " to be very important. The bass section of your 4367s are not horns, and in many instances, ss might just be superior. I am not trying to talk you out of tubes, but I have been down that route, and am committed to ss again, for many reasons. Based on some of your most listened to and enjoyed music, what is it you are looking for ? I am using my many years of working as a professional audio consultant, and I ask this ( and please take this only as I am looking to help you ) as you are still new to high end audio, and you have been kind of all over the map with the desire of putting an excellent system together. Keep in mind, people in this game for 30 + years, still remain in a state of flux, in trying to achieve the same thing. It is really important to know yourself, as to what your rendition of " that stage of performers " should be. If I am speaking out of line, please, gently, let me know, lol. As always, Enjoy ! Grandpa D.
After looking over the very comprehensive description, specs, and manual for the Crimson 275 (and kudos to Bob for even providing a schematic in the manual), my main concern would be about the following (as quoted from the manual):
Bob’s “listen to the room” innovation: Facilitated by a special current feedback loop, it allows the amplifier to ‘hear’ the room’s reverb, along with its unique sonic signature. Each room plays its own tune, and this amp uses the speaker as a microphone by using the speaker in reverse to listen to the room, thereby allowing a portion of the room acoustic to be expressed through the main speakers. The room becomes an integral part of the music in a way no other amplifier allows. Sound is more majestic, more realistic, and the soundstage is larger and more compelling. This phenomenon is impossible to achieve with normal solid-state amplifier designs, whose low source (output) impedance effectively shorts out the speaker’s ability to accomplish this feat.My suggestion is that you consider emailing Bob and asking him the following questions:
1) Why would it be desirable for "a portion of the room acoustic to be expressed through the main speakers"? I would certainly expect that to result in the amp sounding different from others, but not necessarily better.
2) Wouldn't the back-emf produced by the speaker as a result of its response to room reflections be much less than the back-emf the speaker would produce of its own accord as it responds to a music signal, that it would produce even if there were no room (i.e., if it were in an anechoic chamber)? And if so, how can the amp distinguish between the two causes of back-emf? Or does it?
3)Unrelated to that, mightn't the facts that circuit ground is connected directly to chassis and that the filament supplies are AC be conducive to hum problems in some systems, and/or with some tubes?
I owned several of the products Bob produced during his Carver Corporation days back in the 1980s and 1990s, and I certainly agree that he is a brilliant and innovative designer. However, FWIW, my experiences with the sonics of those products were that some were good and some were not so good. A mixed bag, shall we say.
Finally, a couple of nits regarding the manual, which you might want to call to Bob's attention if you email him:
1) The 275 is described as having a push-pull parallel output stage. I suspect that statement was copied from the description of the 350, but the 275 is simply push-pull, not push-pull parallel.
2) I have no idea what the statement that "AC filament voltage is biased to approximately 60 volts" means. The filament voltages supplied to the tubes are 6.3 volts.
Good luck. Regards,
FWIW: Several years ago, I heard the JBL K2’s at T.H.E. Show in Newport Beach. The sound was stunning. Quite surprising since these mid-size speakers were in one of the smallest rooms at the hotel - seating for only 6 people. I revisited that room several times since the music was so inviting. The electronics were Mark Levinson. Don’t recall the model #. But, the two worked great together. Both are owned by Harman. Unfortunately, new Mark Levinson gear is probably above your current budget. Also, the room had carpeting and acoustic wall treatments. With a lively speaker like that, room treatments made a significant improvement.
2) I have no idea what the statement that "AC filament voltage is biased to approximately 60 volts" means. The filament voltages supplied to the tubes are 6.3 volts.@almarg
What this means is that the entire 6.3V filament circuit is floating with respect to ground- except that in this case, it is attached to a voltage divider network that biases the entire thing at about 60 volts above ground. This is done to prevent secondary emission from the filament circuit, which could introduce hum. This puts the cathode as the most negative element in the tube; the electrons will thus be more inclined to flow from cathode to plate, and far less so from filament to plate.
Thanks, Ralph (Atmasphere). Great explanation!
Now that you mention it, I see the approximately 60 volt biasing circuit in the schematic, at the lower left of page 12 of the manual. I hadn't noticed that part of the circuit previously.
I read the Carver’s owners manual. Almarq, yes, Bob’s " listen to the room " innovation ? Allowing the amplifier to hear the room’s reverb ? One of the reasons I stopped using tubes was both acoustical and mechanical feedback, creating microphonics. I always tried to eliminate any reverb in my listening rooms, as well as not allowing the speakers spl to get into my gear. There seems to be a misprint in the tube substitution section, as it duplicates the use of the equipped KT 120s. I am thinking it was supposed to read KT 150s. And a 75 wpc tube amp at under 20 lbs. Are there, or have there been others ? Am I missing something ? Could this be, in fact, the perfect tube amplifier ? D2 girls, what are your thoughts to any of the above, as this is your thread ? Enjoy ! MrD.
Here is some feed back.
Crimson 275 making another Klipsch owner very happy. 100% guaranteed @ JCS.
Ty Jim, It was a pleasure dealing with you. The amp arrived extremely well packed, and in great condition. It is a beautiful piece of art to look at. I love the amp. It drives my La scalla’s II with great details and sound. Appreciate you
I would suggest doing solid state for the bass driver and tubes for the horn driver. Go duo mono if you can, so 4 amps total.
The other option is 3 amps, with 2 SS for the woofer, and last would be two amps, one for the horns, and one for the woofer.
I would recommend quicksilver for the horn and odyssey for the woofer.
Those speakers also benefit a lot from replacing the caps.