Tube amp for "difficult" speakers,,,

Has anyone here tried either the Moscode 401HR [200wpc RMS 8R, 300wpc+ RMS 4R, can be vertically Bi-amped] or the Butler Audio TDB 2250 [250wpc RMS, 8R, 400wps RMS 4R, 800W bridged (mono)] into a low sensitivity circa 83dB loudspeakers with impedance dip to 2R at 20KHz?

Both are hybrid design which whilst giving a valve flavor marry SS in order to provision the power required to drive difficult loads.

Haven't tried them. Can only report back from a Quiksilver monobloc 2 x 60 amp solution, so far. They did not make it, compared to the krell 600, driving the Dynaudio Consequence. Suspect i would need 400 tube watts or more for these speakers.

Have you heard of the new Octave amps from Germany? They are built to drive loads as low as 2ohms.

V/r
Audioquest4life

I own a Butler 2250 and am driving a pair or Ariel 7Bs. The 7Bs are somewhat hard to drive but the Butler seems to have no problem doing so. I listen to my system at 95db to 100db often without issue. I'm not sure you could call the Butler a tube sounding amp in the true since of the word, but I would call it slightly on the warm side. Good luck and keep us posted.

In the last months, I have been comparing apples and oranges - a small OTL amp on headphones and desktop speakers, and my main Krell/Dynaudio Consequence system. So this is really "micro" versus "macro". I use a Korg MR-1 recorder to record LPs on the main system, and playback on the small system, so the nice thing about this testing is that the source is pretty much the same.

Experience? Of course the big system beats the small, in most ways (as it should costing x times more). Music becomes "embodied" in a way the small system cant deliver. At the same time, there is green grass on both sides of the fence, and one should learn to recognize and care about the good points of a system, not listen for what is bad.

In my case, the OTL (Audiotailor Jade) delivers top clarity and a good soundscape that is more neutral than e g my Ming Da tube amp (18 watt single-ended triode) but then, the playing level is different, this is a micro system. OTL in big watt amps may be difficult, or not really the area where this technology shines, I dont know. OTL seems theoretically better, but it has to contribute in a larger context and drive the speakers right.

I have heard a very good OTL system of an audio friend, but it still had a little bit "look in here" quality compared to my own system that "pushes" the listener more. My metaphor after listening to that system was Jewel shrine. I find some of this quality in the Jade too. OTL can sound a bit thin or hollow or cold, but this is much a question of speaker match (no thinness with Jade driving Senn 600 headphones), good tubes, etc. But from my limited experience, SET amps outperform push-pull OTL's (and standard p-pull) especially in the "human" mid-frequency region like reproducing voices.

I am no engineer, possibly, "hybrid" is a way to look, based on this discussion. Musical Fidelity offers a s-state add-on for tube amps that got a good review in Stereophile if i remember right, although adding amps may not be the best thing according to straight wire with gain philosophy.

If someone announced a SET OTL amp 300 watt+, and it got good reviews, I would certainly have liked to try, and might buy it. Today, my speakers thrive with 2x600 watts and my feeling is that they would sound even better with 2x900 (or, two Krell 600s). I think tube amps often have stronger watts, as a rule of thumb, so perhaps 300-400 would do. But then we are looking at extremely expensive niche products.

A question is, if this is due to taking a technology out of its "easy" terrain. Solid-state + big watts= quite easy. Tube Set and Otl low watt - easy. Each of these, to middle-low watt - quite easy, like 20 w triode. Combined not so easy. Higher wattage - very difficult. Correct?

I heard the Dynaudio Consequence Ultimate at a demo in Oslo recently, powered by Macintosh monoblocs, no less than 3 huge boxes behind each speaker. Since it was an amp setup in the extreme price range I didn't investigate further. Sure, the CU's rocked, and I could hear improvements from my own mk2 (standard) C's. But I was also thinking that some of the sound reflected the amps and that standard C's, too, would have played more lively with greater unconstrained presence, if hooked up. Obviously Dynaudio hasn't changed the basic power hungry character of the speaker (complex design kept + improved, better drivers + x-overs). I asked the D representative "what kind of amp do they need", and he claimed that they would play well on smaller amps also. I don't believe it.

Just for your information, Atmasphere MA1-s cannot drive Dynaudio Consequence speakers (i have mk2). This is no big surprise but I wanted to mention it so you don't mis-invest your money. Using autoformers helps a bit but not enough. Both are great products. They just were not made for each other. MA2-s might be another story, and perhaps MA3-s would sound great with these speakers. They demand lots of power, as many others have written.

CAT JL-2. Not clear if you are still in the market and I would not want to spring for any tube amp of the size you will need without auditioning it with your speakers. Having said that, I've not seen any tube amp (or most SS) that handle difficult speakers like a CAT JL2. You are looking at a big, heavy, hot amp but it handily outclasses anything I've heard on my Apogee Diva's (and before them, Infinity Beta's). At one point I used it to drive some older speakers I built with Strathearn ribbons (1.1 ohm load). Have never heard it sound less than wonderful.

mbhintz

100% agree on the CAT JL2, which I owned for several years before switching to Atma-sphere M-60s which drive my "easy" speakers to perfection.

Update: I ended up selling my speakers and amp. I now use tube monoblocs with less demanding speakers, and enjoy it.

O holter,

Just curious what did you end up with?

Regards,

Soon to be Dynaudio Confidence C-1 ii owner with 70 Conrad Johnson tube watts that may not be enough :)

Hi cjinsc, by 2017 I have ended up with Atmasphere MA-1 mk 3.2 amps driving Audiokinesis Dream Maker speakers, augmented by a modified (bridge coupled) Pioneer 912 driving Audiokinesis LCS speakers (you can see my updates in my system blog here at the forum). The LCS upgrade was needed to get a volume level more tuned to rock music and the the big Krell sound that I was used to, in my fairly large listening room. I am happy with this solution. The system sounds good even when parts of my front end are in for repair, and I have to replace with a cheap component, just to be able to play music. Its almost like a jazz combo. The front end (amp speaker room combination) of the system continues to play very well, very musically convincing, whatever the input.  So,I don't look back.