Audio Research Amp Filling in for Ultra 550

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EclecticSeeker

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Audio Research Amp Filling in for Ultra 550
« on: 28 Mar 2009, 11:20 pm »
Greetings, all.
I don’t post often, but I think a recent audio experience I have had might be of interest. 

I occasionally get to travel to different states and cities, and when I do, my favorite activity is to visit their audio dealers to check out different lines of gear that I don’t usually get to audition.  On one such a recent trip, I came across a used Audio Research VS55 amp that had just been traded in.  I listened to it for a while, was very impressed with the sound, and decided to try it out.  The asking price seemed fair (I think it was just under $3000 new), and I think it’s no exaggeration to say that AR gear is among the most highly regarded in the world. 

The VS55 is a 50 wpc tube amp, which was replaced in the AR line not too long ago.  It had to be shipped to me, and when it finally arrived, I waited until I had time to do it right.  I listened to a few of my ‘reference’ CD’s on my system, then pulled my Ultra 550 out and plugged the VS55 in in its place. 

The Audio Research VS55 certainly has at least some of that acclaimed “tube magic.”  I can see listeners becoming enchanted with it, and can quite understand why some people fall in love with AR gear (and/or the ‘analog sound’).  This amp has what I believe is characterized as a “modern” tube sound, without the high-end softness that tube amps are often accused of having and that I have often heard.  My Quad speakers are very revealing, and the high end seems to sail all the way out there – smooth, clean, and non-fatiguing.  The bass is present and solid, if not quite as open, defined, or well-controlled as it could be.  The upper midrange might not be quite as prominent as I think it should be.  Depth is excellent, but not awesome.  There is a wonderful soundstage, with instruments (in a decent recording) originating from their own location in space.  The amp provides what is absolutely an enjoyable and involving high-end experience. 

Before I comment further, yes, I know that the VS55 has only about 1/5th of the rated power output of the Ultra 550, and it is absolutely not a fair comparison in that light – in this respect, it’s almost apples to oranges.  I will say, however, that I run a modified Dahlquist LP1 crossover in my system that relieves the more power-demanding low end from the main amp for delivery to my subwoofers.  The VS55 never shows signs of strain or running out of headroom. 

So how does the sound of the VS55 compare to the Ultra 550?  (Well, I’d probably not be posting this to the AVA AudioCircle if it came out ahead.)  The 550 provides more of everything.  More extension, more depth, (usually) more definition, more soundstage, more dynamic range, even more transparency – the list goes on.  I think it is in the presentation of soundstage that the VS55 challenges the 550 most successfully, and even there the 550 prevails. 

A comparison of the 550 with a newer, bigger brother of the VS55 would doubtless be more fair and most likely have less of a performance gap.  An A-B with, for example, the higher-end Reference 110 model would be most enlightening.  (Of course that baby costs $9,995, and I’ll have to leave that experiment to someone else!)  Even so, I’d be willing to bet that the Ultra 550 (or Double 550) would still come out as the better amp in my system. 

I will try the VS55 with some other speakers before deciding to part with it, but I suspect that it will wind up listed on Audiogon in the not-distant future.  For now, it is doing very nicely as a fill-in amp for me.  Fill-in?  Well, my 550 is currently at AVA for the Double upgrade.  I miss it, and await its return with great anticipation.

My best to you all. 

Tone Depth

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Re: Audio Research Amp Filling in for Ultra 550
« Reply #1 on: 29 Mar 2009, 01:19 am »
Congrats on your decision and order.  Please post your impressions of your Ultra Double 550 upgrade after you get it back.

DSK

Re: Audio Research Amp Filling in for Ultra 550
« Reply #2 on: 29 Mar 2009, 08:39 am »
Hi EclecticSeeker, always nice to hear about the Davids of this world knocking off the Goliaths  :thumb:

Out of interest, what speakers were you using (impedance & sensitivity rating)?



Anji12305

Reactive loads and tubes
« Reply #3 on: 29 Mar 2009, 01:01 pm »
Tubes handle purely resistive loads well.
Here's a discussion that seems to summarize the notion.
<http://www.symphonysound.com/articles/tubefriendly.html>

I use Magneplanar panels for Bass/Midrange and Newform Ribbons above 1kHz.
Even a strapped pentode (acting as triode) handles this kind of load pretty easily.

What it can't do is handle complex musical passages with large bass frequency demand.
For that, the Double 550 will be the obvious favorite.

What sort of speakers are you driving?  If the impedance curve and phase angles are published, it could be telling.

EclecticSeeker

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Re: Audio Research Amp Filling in for Ultra 550
« Reply #4 on: 29 Mar 2009, 03:45 pm »
Hi EclecticSeeker, always nice to hear about the Davids of this world knocking off the Goliaths  :thumb:

Out of interest, what speakers were you using (impedance & sensitivity rating)?




Thanks for your interest.  I have Quad 2905 electrostatics.  Impedance is 8 ohms nominal, 4-20 ohm variation.  Sensitivity is published at 86dB/2.83v.  While that sensitivity is not high, the Quads are known to be “tube friendly,” and some owners drive them full range with tube amps of as little as 30 watts.  I do use a crossover (a highly modified Dahlquist LP1) to connect two powered B&W ASW825 subwoofers.  My cut-off is currently set at 45 Hz, though I need to experiment with that more. 
I am blessed with a large room that will accommodate this system and allow it to really sing…
As I mentioned, the Quads are extremely revealing, and any change in the system is readily and easily discernable.  The VS55 proves itself to be one damnfine amp.  As I have posted before, Frank’s electronics will usually embarrass other manufacturer’s gear costing much more.  Though that embarrassment factor isn’t quite as high in this case as it usually is, there is no contest between the VS55 and Ultra 550.  The quality and value of AVA remains unquestionable and unchallenged.

Brett Buck

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Re: Audio Research Amp Filling in for Ultra 550
« Reply #5 on: 29 Mar 2009, 07:53 pm »
two powered B&W ASW825 subwoofers. 

    Uh, wow, 2KW of subwoofers? Might want to report that to the USGS, they were wondering where those earthquakes were coming from.

    Brett

boycephoto

Re: Audio Research Amp Filling in for Ultra 550
« Reply #6 on: 30 Mar 2009, 02:50 am »
Hi EclecticSeeker,

I have sent you a PM.  Thanks

Dave