Showing posts with label how do they sound. Show all posts
Showing posts with label how do they sound. Show all posts

Saturday, February 15, 2014

Tube Review: The Valve Art 350B pentode


Introduction:
The original Western Electric 350B - which I've only heard in a few rare instances - has become one very expensive output tube.  Valve Art, through Shuguang, currently makes a "reproduction" that is extremely affordable and has a nice vintage "G" bulb shape that would look quite good in a pair of Quad II monoblocks or any other vintage amplifier that can handle the extra filament current of the 350B over the more pedestrian 6L6GC.

I purchased a pair of Valve Art 350B from Antique Electronic Supply.  Price is less than $40 a pair, which is quite inexpensive compared to the majority of NOS and even new tubes.  Construction quality is quite high with  welded plates, good looking mica, two vertical support rods, and white ceramic spacers.  No, it isn't anything like a 1940s 807, but it looks pretty close - perhaps if you rubbed off the Valve Art logo it could fool some of your more tube savvy friends... or not.

I plugged the 350Bs into my Multi-Valve amplifier which has adjustable fixed bias.  I dialed them in at a healthy 60mA, perhaps 50mA would be a safer bet for long life, but at this price I'm willing to give up a little longevity for a few (and I mean a very few) extra watts.  After all, I'm not running horn tweeters in a multi-amp system, but a pair of full-range speakers that can take whatever I can dish out.  At this bias setting there was no sign or red plating and the tubes have been working perfectly after a good solid 100 hours or more.  So much for the myth of poor Chinese tube reliability. 

Listening:
The first record up was Neil Young - Live At The Cellar Door.  Detail - audience coughs and  hall ambiance were all there - perhaps lacking compared to the best NOS I've heard, notably the Philips metal base EL34s and vintage Tung Sol 6550s.  However no frequency aberration stuck out and there didn't seem to be any of the "solid state in a bottle" bleaching that is often the hallmark of new production tubes.  This recording, however, is not the most dynamic so it was time to move on to something else.

My Japanese pressing of The Police - Synchronicity is an exciting and bouncy album requiring plenty of power to unravel everything that is going on.  With the Valve Art 350Bs, I noticed that the bass didn't go as low as the vintage Tung Sol 6550s.  The 350B sounded compressed and confused on the big peaks - perhaps hitting the edge of their power envelope in this single-ended amplifier.   A more efficient speaker could perhaps ameliorate this issue.  I also noticed a touch of dryness - though maybe this is a function of the recording itself.

Pink Floyd - Animals is a perennial favorite of mine - my German pressing is very dynamic with tons of detail.  With the Valve Art 350B, I noticed a murkiness to the sound as if a layer of gauze was making the finer detail and attack of the songs.  Sure, the music was still there, but I found my mind wandering.  The "swirl" - as I call it - was missing; this is the moment when the notes become visual, engrossing the mind with music.  Depth also become shorter and the soundstaging less enveloping than normal.

I tried a few other albums - Roxy Music, Dr. John, an Agalloch CD - and found that the quieter cuts fared better.  Once the dynamics cranked up, the bass would become plodding and the music unrefined, bringing down the system sound quality down several notches - turning my pride and joy into a sonic mess.  Adjusting the current down to 50mA didn't seem to make any difference either.

Conclusion:
I really, really wanted to like these tubes.  I mean they look great and I'm usually a champion of Chinese tubes, but - at least with this amplifier - I cannot recommend the Valve Art 350B.  Perhaps in push-pull or with a different transformer load, voltage, or current, or even cathode bias they would shine.  Or maybe I was asking too much out of them, but the SED 6L6GC in the same circuit sounded much better.


Review System:
VPI Aries with JMW 10.5i tonearm and SDS Power Supply
Dynavector 10X5
Cardas Cross 1M interconnects
Quicksilver preamplifier with Mullard short-plate 12AX7s, RCA 12FQ7s, Amperex 12AU7
Cardas Quadlink 5C 1M interconnects
Multi-Valve Stereo amplifier
Cardas Hexlink speaker cable
UREI 813A monitor speakers
VTI BL503 equipment rack


Friday, April 26, 2013

Review: B&W Matrix 805 loudspeakers

 Introduction
Bowers and Wilkins have long been audiophile darlings.  I'm no historical expert, but from my many years of reading the audio specialty magazines, it is the venerable 801 studio monitor that cemented their reputation.  Unlike many other speaker makers, they also produce their own drivers, and have an engineering staff on board to build excellent crossovers and cabinets.  This attention to quality is hardly extraordinary in the world of audiophiles, but like their British competitor KEF, it speaks of a long term love of the black arts of speaker design.

My own personal experience with B&W is very, very short.  The only pair I've personally heard was back in the 80s, when my best friend had a pair of stand mounted units of an unknown model.  I don't specifically remember much about the sound other than the speakers could take all the power that the Denon receiver could dish out.  This was, of course, before my audiophile days, when playing clean and loud was all that mattered to my teenage ears.

Time for a New Speaker?
Moving to a new house with a smaller listening space, and a Denon DL-103R cartridge that got damaged during the move, tempered my audiophile equipment craving.  Instead I pulled back on my expenditures, scaling back the size and quality of my system by going with a pair of KEF iQ30 speakers that I already owned, and buying a new Denon DL-110 cartridge.  I even stuck in some Chinese EL34 tubes for my Eico HF60 monoblocks, wanting to save my vintage Mullards for the day when I had a larger listening room.

However, fate being what it is, those plans of hanging back were thwarted by the purchase of a VPI Aries 1.  This was not a turntable purchase that I was planning to make, but it was such a hard deal to pass up - being local and priced lower than what I was seeing on Audiogon - that I took the plunge.  The resulting sound, even through the budget KEF monitors, was a major eye-opener.  I'll be reviewing this turntable in a separate post, but needless to say the overall sound, even with a budget priced Denon DL-110, became much more dynamic, involving, and was quite the step up in reproduction.  After hearing the Aries, I knew that to get the full effect I had to upgrade the rest of my stereo system.  I also knew that with my smaller listening space that approaching the bass and dynamics of the UREI would be near impossible, but perhaps I could be sated with a mini-monitor of high enough quality.

My initial thought was to go with KEF - specifically the KEF LS50, but the low efficiency of 85dB made me wonder if 60Ws of tube power would be enough.  The lower-end models of KEF had their own issues.  For example I wondered if the current Q300 model would really be a major upgrade versus the iQ30s currently in the system.  Browsing through Audiogon for monitors under one thousand dollars, I came across the B&W Matrix 805s, the baby brother of the famed 801s.  My interest piqued, I read the Stereophile review and this post by Ken Rockwell.  Both are excellent starting points if you wish to have a deeper technical description of these speakers.  Needless to say, I was thoroughly interest in this speaker now.  Though the efficiency is only a rated 87dB, it still seemed worth taking the risk.  I purchased the 805s and soon had them in my hands.

Initial Impressions
Opening the box and unwrapping the yards of bubble wrap, I was greeted with a very nicely built pair of mini-monitors.  The enclosure made of rosewood (veneer?) is very lovely.  Binding posts on the rear are recessed and gold.  The woofer is a 6.5" kevlar unit while the removable bullet tweeter on top is a metal dome that is time-aligned by a fourth-order crossover.  An extra feature is the optional outboard electronic crossover/filer the cuts bass off below 10Hz but firms up the response between 10Hz and 50Hz.  This could be useful to reduce turntable subsonics and improve the low-end for rock or symphony music.

Installation was on top of my UTI 29" tall stands, bi-wired with budget Kimber 8PR/4PR.  Distance between the speakers was some 7' from each other and perhaps 2' from the sidewalls and 3' from the rear wall.  Obviously not a cavernous listening area, eh?

Using the Denon DL-110 cartridge, along with Hitachi 5AR4s and Shuguang EL34s installed in the Eico HF60s.  The first record up on the Aries 1 turntable was Neil Young's "Live at Massey Hall".  This recording is fantastic - however with only one singer and guitar (or piano) it is by no means a complex or very dynamic album.  Nonetheless, it is a good album for picking out overall sound quality.  The treble sounded very clean and polite.  The midrange was clear with plenty of detail and space.  The bass, which isn't very deep on this album, had a slightly wooden character.

The next two albums: a German pressing of Pink Floyd's "Animals" and a Japanese pressing of Steely Dan's "Greatest Hits" showed the natural limitations of all small speakers.  As expected, ultimate dynamic range and the lower bass of the B&W 805s were limited by the small woofer size.  Yes, I'm being quite unfair comparing such a minute speaker to the massive UREI 813As, but I'm just reporting what I heard.  When the bass got really deep, the 805s didn't choke, but instead began to slowly compress, leading to the already mentioned wooden character to the bass.  However, throughout the dynamic swings, the sound still remained balanced and focused without getting gritty or uncontrolled like the KEF iQ30s.

Getting Deeper:
Now it was time to upgrade the rest of my system.  First it was a new cartridge: the Dynavector 10X5.  This is a good, dynamic high output moving-coil cartridge that works quite well with the Aries 1 turntable.  After that, it was time to bring out the best tubes I had for my Eico HF-60s.  Out went the Hitachi and Shuguangs, and in went my vintage Mullard tubes.  I also replaced the GEC CV4085s (EF86) with the very earliest and rare "long plate" versions that Mullard made.

These changes were proof positive that rolling in the right tubes can have a major impact on the sound.  Not only did the midrange become more relaxed, but the higher frequencies were even smoother than before.  The Dynavector 10X5 has always been a dynamic cartridge and partnered well with the B&W 805s.  Sure, the UREI 813As still hold sway in the explosive bass department, but for such a small speaker, the overall frequency response was much improved.

You Got to Equalize! 
B&W also included a small bass equalizer with the 805s.  Since I didn't have another pair of Cardas interconnects on hand, I opted to use some budget Canare wire to make the connection between the Quicksilver preamplifier and bass equalizer.  From the output of this little unit, Cardas Cross wire was used.

The change was immediately apparent - this small speaker now growled like a much larger speaker.  Again, it was nothing like a big speaker with multiple drivers, but it sure helped with rock 'n' roll music.  The wooden character of the bass was gone and instead became really firm and punchy.  However there was a bit of detail loss, but for the types of music I listen to, I definitely preferred the improved bass response.  Now I will have to go ahead and buy a short run of Cardas interconnects.  However purists or listeners of lighter fare may prefer the speakers without the additional wiring and active equalization.  Try it both ways.

Speaker Cable Upgrade:
The Kimber 8PR/4PR is great budget wire, but I was curious to hear how my vintage Cardas Hexlink speaker cable would fare.  So back in went the binding post jumpers on the 805s, and on went the Cardas.  The change was quite immediate - the slightly bright, polite sound became much more relaxed.  The top-end treble also smoothed out, turning the monitor into one warm, full-bodied speaker.  Wow.   I would never expect such a major character change from a few feet of cable.

Details R Us
Bass Response:  Hey, this is a small speaker with a relatively tiny woofer.  Expecting subterranean bass suitable for hard rock or organ music is just plain wishful thinking.  If you like that kind of music, you either need a larger speaker or an additional subwoofer.  However, with the B&W bass equalizer installed, lower frequencies are served well enough that I don't miss my big studio monitors (too much).  The sound became really punchy with good detail.  It wasn't all boom either, but instead the bass became very tight and controlled.  Obviously some thinking went into the speaker crossover design and the additional needs of the equalizer.  Again, very dependent on system and musical tastes.

Midrange: Compared to the UREI 813As, which are ruthlessly neutral as befitting a real studio monitor, the 805s have a slightly recessed sound when using the Kimber wire.  This was tremendously reduced by the Cardas cable.  When the music gets really busy or the dynamics really start swinging, it's almost as if the speaker is slightly "holding back" as the big peaks swell up.  Once again, perhaps this is just the effect of a small speaker being asked to do the work of a larger one.

Detail was exemplary - fingers on strings, studio effects, and overdubs were just that more obvious than many other (more budget) speakers I've heard.  The level of available information was much higher than my old Magnepan 1.6QRs, but not quite in the Quad ESL-63 league.

Treble:  The 805 tweeter ranks up there with some of the better I've heard.  It's clean but not totally antiseptic.  It's also very detailed  Sure, it doesn't quite strike in the electrostatic speaker or the plasma tweeter level, but it's no slouch either.  Admittedly there is a slight bump in the highest of frequencies, so some system matching is paramount here.  For example, the wrong solid-state amplification or an aggressive moving-coil or DAC could play havoc with the system balance.  Be also sure to play with speaker wire, as my Kimber vs. Cardas experiment proved.

Other: Even at loud listening levels, the 805s never fall apart.  That is to say the speakers never sound ragged or uncontrolled.  Soundstaging placement, width and depth are also very good, letting instruments and voices sit naturally within the space of the recording.  There was some minor shrinkage - as to be expected - of image size compared to larger speakers.

Conclusion:
Speakers in the less than one-thousand dollar range are a hard nut to crack.  My advice in this range is to buy the best used model you can afford.  The B&W Matrix 805 is one such model.  I'm sure there are many others, but few in this price range can match the engineering, quality, and performance of these top level speakers.  I expect the 805s to have a long shelf-life in my current system.  Highly recommended.

Review System:
VPI Aries with JMW 10.5i tonearm and SDS Power Supply
Dynavector 10X5
Cardas Quadlink 5C 1M interconnects
Quicksilver preamplifier with Mullard short-plate 12AX7s, RCA 12FQ7s, Raytheon black-plate 5814
Cardas Cross 1M interconnects
EICO HF-60 monoblocks with Mullard XF2 EL34s, EF86s, 5AR4s, and GE 6SN7GTAs.
Kimber 8PR/4PR 2M bi-wire cable or Cardas Hexlink
VTI UF29 stands
VTI BL503 equipment rack