audio research REF 150

Ref 150 update: still loving the amp.

I continue to be impressed by the amp's ability to negotiate (if that's proper audio-speak) complex musical passages and effortlessly handle transients. The dynamic headroom is just fantastic -- I guess that speaks to the upgraded 1000 joule power supply. Double the Ref 110's.

Even though bass slam and low end extension is somewhat better off of the 4 ohm taps (probably because it's the lowest output impedance tap), as I've posted elsewhere, so far, I think my speakers sound their overall best when plugged into the 8 ohm taps.

3-D imaging and soundstage are eerie. My speakers are just about invisible. Imaging seems to be about 2 or 3 feet behind the speaker fronts and I can almost discern where voices and instruments are located. Overall acoustic presentation is excellent.

If you're in the market for a tube amp, I highly recommend this amp. Just a caveat. As I have also commented elsewhere, electrical compatibility with your speakers is key. Do your research and try to audition a like combo if possible. There are many threads running about this issue.

Cheers,

Bruce

Ref 150 post -- Thought it was worthwhile to share one more quick reaction.

Was listening to Von Karajan conducting the Berlin Philharmonic performing Brahms 2nd and 3rd Symphonies (DG redbook CD). Let's just say that Brahms must have been feeing real good when he composed these works because when well performed the incredible dynamic range and mix of instruments could easily overwhelm any system. I was extremely impressed by the poise and control that my rig had over the music.

Not sure if the Ref 150 gets all the kudos or ARC system synergy deserves some too. I suspect the amp deserves the lion's share of the credit though.

Btw, I'm running a little experiment with the "redbook" CD side of the house. I order Gold and HD XRS (?? thinks that's the designation) quality "redbook" CDs from Acoustic Sounds (one each). These designations are supposed to show that the CDs were mastered and produced with lots of TLC and are supposed to sound better. I should receive the CDs in a few days. I'll post my comments here and on one the digital quality threads.

Good evening .

I have been having a little "FuN" switching the output taps on a REF-150 driving Martin Logan CLX's and find myself concurring with a post made by another member , sfischer1, earlier in this thread ~

"11-21-11: Sfischer1
Just spent a couple full days using a demo 150 with my Martin Logan CLX full range electrostatics. Even though the MLs have a tough impedance that drops to an ohm at high frequencies, the best sounding tap by a large margin was the 16 ohm connection"

Considering the CLX's nominal 6 Ohms impedance dipping down to 0.7 Ohms @ 20K would not our subjective findings contradict the recommendation made by John Atkinson contained within the Stereophile review ~

" All taps behaved similarly when it came to the maximum output power. Into a load twice the nominal tap value, the Ref150 clipped (defined as 1% THD) at 90W (19.6dBW, fig.4). Into the nominal tap value, it clipped at the specified 150W (21.75dBW, fig.5), but with a higher level of distortion. Into half the tap value, the amplifier clipped at 80W (13dBW, fig.6), but with even higher distortion at lower powers. It is important, therefore, to use the transformer tap that best matches your preferred loudspeaker."

" with the caveat that it performs at its best with loudspeakers that have impedances equal to or higher than the nominal output-tap impedance.—John Atkinson "

Where is that 'confused' emoticon when one needs one !

has anybody tried the tung-sol kt 120 or 6550 in this power amp I have 1500 hrs may need to change soon

Ollies ... I assume by your reference to "this power amp" that are referring to the Ref 150. If so, I am puzzled by your question because KT-120s come standard with the Ref 150.

Although there may be other companies that manufacture the KT-120 ... the ARC standard issue *IS* Tung Sol, a redo by the Reflektor company in Russia. The 6550 does NOT come standard with the Ref 150.

Perhaps I do not understand your post. If not, please explain.