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Best Tube Based Options For B&W 803S Speakers

Thinking about taking the plunge into the tube arena to soften up the highs in my 803S speakers. I currently have an Anthem AVM30 using Genelec speakers in a 5.1 theatre system as well as an Anthem A2 pushing the 803S for 2 channel. I will be upgrading to a 7.1 processor at some point possibly the Marantz 8801 and considering an upgrade to the Oppo 105 as well.

My immediate concern is what would make the most sense and be cost effective in terms of trying out some tube equipment for a 2 channel rig. Perhaps keep the A2 and try a tube preamp, or sell it and try an integrated tube amp. Maybe try some type of tube based CD player using the analog bypass in the theatre processor. My budget is around $2,500 used and I am looking for something easy to maintain.

Comments are much appreciated thanks.

bullitt731
almarg's avatar
almarg
9,670 posts
 
Good input from Lewinski. I would add, though, that the output impedance of the MC275 is much lower than that of most tube amps. I had said earlier in the thread that:
Impedance curves for several other B&W models, including some that seem to have a degree of commonality with the design of the 803S, all show a rise to very high impedance values (well above 20 ohms) in the upper midrange/lower treble area, around 2 to 4 kHz or so.

The interaction of that kind of impedance variation with the relatively high output impedance of a tube amp will result in greater emphasis of those particular frequencies, relative to other frequencies, in comparison with the frequency response that would occur with a solid state amp. That would seem to be the opposite of what you are trying to accomplish, namely softening the highs.
The current Mark VI version of the MC275 has a specified damping factor of 22, which is much higher than that of most tube amps, and theoretically corresponds to unusually low output impedances (for a tube amp) of 8/22 = 0.36 ohms for the 8 ohm tap, and 4/22 = 0.18 ohms for the 4 ohm tap. John Atkinson's measurements of the Mark V version are only slightly higher than those values.

So the tonal balance effects of the interaction between the MC275's output impedance and the speaker's impedance vs. frequency characteristics will be considerably closer to those of a solid state amp than will be the case with most tube amps.

Regards,
-- Al
zd542
5,339 posts
 
"07-27-14: Abrew19
Matrix 800 series tweeters were the best around at the time. The 801s and 800 were Stereophile Class A regulars and the 805 was up there too for a long time. Methinks you have something different about your ears ..."

I don't know how you come up with those tweeters being the best available at the time. That's another one I've never heard from anyone. Its possible that your hearing may be rolled off a bit, and/or have some wax buildup. I know a few people like this. They just don't hear the sibilance/harshness that most people hear. As far as Stereophile goes, I think you'll get a better sounding system doing just the opposite of what they say.
georgehifi's avatar
georgehifi
10,312 posts
 
Bullitt731 hi,

This is the only impedance graph I could find, and yes it does look to be tube friendly for good push pull tubes with low output impedance.

But this graph needs to be read in conjuction with a phase angle graph as well, and there are none of these around.
If the phase angle dips to -30 or more degrees at the 3ohm to 4ohm impedance between 50hz and 700hz, which some of the later floor standing 8 series do, then this can then look to the amp as a 2ohm or even lower impedance.
And a tube, even good powerfull one may sound a bit light on in the lower mids and upper and lower bass, and therefore maybe sound too lean and bright overall.

So unless you can find a phase graph, I would stay clear of tubes and even wimpy solid state.

http://www.htguide.com/forum/showthread.php?14694-Test-in-STEREO-803s-against-803d&s=bd734233c26b3cfa17fa522d0de3e468&p=191324&viewfull=1#post191324

Cheers George

joey_v
669 posts
 
Loaned my brother my Cary SLP-05 tube preamp hooked to his SS musical fidelity amp... Got rid of any remaining sibilance on his. 804 Diamonds... Fantastic sound.
abrew19
146 posts
 
"As far as Stereophile goes, I think you'll get a better sounding system doing just the opposite of what they say."

Wow, why didn't I think of that? Go exactly the opposite direction. So I presume you're a big fan of Bose maybe?

About the Matrix 800 series tweeters, if you care to read more
http://www.stereophile.com/content/bw-matrix-805-loudspeaker-page-2

Quoting the reviewer Larry Greenhill "The 805's tweeter is almost in a class by itself."

Other rave reviews
Matrix 800
http://www.stereophile.com/floorloudspeakers/691bw800/index.html

Matrix 801
http://www.stereophile.com/floorloudspeakers/506/index.html

Yep, these speakers are true MONITORS and will indeed reveal what is in the source material. You need good equipment to match with these speakers -- otherwise you are wasting your time. Poor recordings will be bothersome. And BRIGHT recordings will sound harsh. There is your "ice pick" reference.

I don't blame the speaker for that. Obviously you do. To each his own.
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