Several months ago I decided to throw caution to the winds.
After being an Open Baffle enthusiast on the cheap for 10 years, I purchased a pair of Lowther PM5A Alnico/Ticonal drivers from Lowther America working with Jon Ver Halen. Jon is a wonderful person to work with, very knowledgable and not afraid to share what he knows. I also purchased a Yamamoto Sound Craft A-08S Single Ended Triode 45 tube amplifier directly from Shigeki Yamamoto, the Japanese master, working with him through emails. Yamamoto no longer has a dealer in the US. Since the pair of Lowthers I purchased are 15 ohm, I asked Shigeki to use a 16 ohm output transformer so there will be an efficient match between his 45 amplifier and the Lowthers. I wanted to be able to potentially use every trace of the 2 watts the 45 tube could deliver.
I was a little nervous not knowing if the 2 watts of the A-08S could adequately drive the Lowthers. The Lowther site in England states the Lowther PM5A is 96 db sensitive. “They measure a little differently over there than we do, Richard. I would say the sensitivity is closer to 98 or 99 db”, Jon reassured me. Jon was right, I need not have worried. This combination can play very loud without distortion, much louder than I would ever want to play it.
When I was ready to purchase the PM5A's, Jon told me that he had a Ticonal version of the Alnico magnet and wanted me to have it, which made me intensely excited. I had heard a great deal of praise about this extremely rare, legendary and apparently out-of-production version of the Lowther Alnico magnet which contains an added ‘secret’ ingredient of magnesium. “Fantastic ambient retrieval” Jon suggested.
Srajan of 6 moons suggested that the Yamamoto A-08S has a ‘modernized’ application of the original 1930’s SET circuit that leans closer to a solid state perspective than a design that renders a ‘romantic' tube experience. The speed of the Yamamoto A-08S made me think that the Alnico magnet might be a good match with its emphasis on ‘ambient’ retrieval over the more detailed presentation offered by the Neodymium or Ferrite magnets used by Lowther. There was some controversy about Shigeki’s use of the DC heaters in the circuit in the newer S version of his 45 SET. Some purists and other SET designers felt that it may not express the ‘tone’ of the original circuit which uses AC heaters. Srajan wades in, "By DC-coupling the 45s and 717A drivers, noise levels for the revised amp are given as 0.3mV to 0.7mV. Tonal qualities of the A-08S are now felt to be superior even to the very best 300B amps. Further "S" changes include a switch from the 5U4G to the 80 rectifier which was developed in tandem with the original 45s way back when. To the designer, this presents a logical marriage of vintage origins.”
The A0-8S is shockingly quiet. The music is cast against an infinitely quiet background with a clearly articulated textural presence. The sense of ambient space around instruments and voices revealing the presence of the room in which the music was recorded is stunning. Combined with the Lowther PM5A, the tonal presentation is surreal and fully saturated. And yet I think it is the harmonic complexity, the subtle inner-detail, the shimmering after-sounds that reverberate after a string is bowed or plucked, or a cymbal is struck, or as the breath is just leaving a clarinet, or any other wind instrument, or the subtle modulations of the voice as the sound is shaped by the lips and tongue, as well as the explosive sense of immediacy and suddenness when an instrument or voice begins to sound, that creates the uncanny effect that nothing is separating you from the music spilling into the room.
We are speaking of music expressed through many different musical forms, the emotional intensity of classical Japanese singing with Koto accompaniment, the ancient imperial court music of gagaku, the Blues of John Lee Hooker, late Mozart quintets or the late quartets of Shostakovitch, Miles Davies’s Kind of Blue, Billie Holiday and Melody Gardot, classical Dhrupad chanting, the emotional power of Nina Simon, the contemporary work of Arvo Part, especially his subtle choral works, Julia Kent or Osvaldo Golijov, everything comes to life.
I also decided to re-design the Open Baffle panels by cutting them down to a visually satisfying minimum. Deborah chose an off-white color to paint them that she felt would go nicely with our new pickled-oak laminate floor. The scale of the new panels is so easy to live with; they are extremely light-weight, easy to move around, and the off-white color Deborah chose sets off the whiter, yet still creamy-colored Lowther drivers. Nice!
Like most of our DIY Open Baffle community I am using what I have on hand to fill-in for the rest of the system. A few years ago I purchased the small Milllenia TBI class-D 7-watt amp as a back-up to substitute for my problematic Heathkit re-designed tube amp, until I was able to figure out what to do next. I was not ready for major research nor a major purchase at that time. I now use the Millenia as a dedicated amplifier for the Eminence 15A bass drivers. I dusted off the original passive preamplifier made by Luminous Audio, really a voltage regulator, that I used for all of my previous SET amplifiers, to work as a volume control for the Yamamoto.
The Lowther’s are known for long 'break-in’ periods and my experience was not different, although within 3 months of modest playing things smoothed out nicely. The Yammie also needed time to ‘break-in’, so I let them ‘break-in’ together.
At first I used my mass-produced, cheap, rather un-refined, but dynamic CD player. Then I began to use an older iPad Mini to stream from Pandora. Pandora's streams sounded remarkably good through the iPad Mini with admittedly some loss of detail, until about 2 weeks ago when they ‘upgraded’ their web site and the ‘spatial’ presentation I heard before disappeared and in its place was a hard flat dimensionless musical landscape. I jumped into Spotify to see whether it could sound better. After signing-up for the Premium service I chose the highest resolution stream, 320 kbps, that they currently offer.
I began to stream music into my new system and was immediately stunned. What I heard, and continue to hear, is the most exquisite musical presentation I have ever heard from an audio system. Deborah was even more stunned than I was. She commented, “It is like the music explodes into the room, creating its own sense of space, sounding exactly like the instrument or voice, with incredible excitement!”.
Before I switched to Spotify I liked the new set-up and thought it sounded comparable to the new Magnapan .7 drivers Deborah and I heard a few weeks ago in a showroom in LA. But with the music now streaming from Spotify at 320 kbps, through my lowly iPad Mini with a built-in DAC that probably cost only a few dollars, the sound is utterly mind-glowingly fantastic. Any of the usual considerations about audio, how well it does this or that, now seems totally irrelevant.
Of course it is the Open Baffle paradigm that allows the music to launch into 'aliveness' in the way that it does. The way that the sound impregnates the air of the room and encourages it to burst into musical life. As Deborah suggested, the dynamic presentation literally leaps beyond any perception that the music we are listening to is recorded and being re-created by mechanical devices. Everything sounds utterly alive!
We are obviously happy with our set up as it is right now. However, there is room for improvement. For one thing, Luminous Audio now offers a very sophisticated version of their original passive preamplifier, which I am tempted to purchase. I am using a pair of NOS RCA 45 tubes purchased several years ago and there is a consensus that the gigantic EML 45 tubes sound even more dynamic. The interconnects and speaker cables are not necessarily designed for the Yammie, Lowther combination. The Millenia may not go down as far, perhaps, as a dedicated plate amp might, and I am using a simple coiled inductor to cross-over the Eminence 15” drivers at 250 Hz, which may be detracting from the performance of these modest drivers. A dedicated plate amp with a high cross-over option might work better, although be less convenient to adjust ‘on the fly’, being usually relegated to the back of the panels.
The Lowther PM5A’s loses its low end rather higher than I would have expected, due no doubt, to the small baffle area it now resides in. And just as strangely, the lowly Eminence 15” drivers easily and seamlessly blend with the Lowthers so that from the midrange on down the sound is fast, rich, ripe and musically satisfying. There is absolutely no sense that the music is being presented from a divided source.
I like the ability of ‘shaping’ the sound somewhat by going back and forth between the passive preamplifier for the Yammie A-08S and the volume control on the Millenia. For example, I simply add the perfect amount of bass I want after I first choose volume on the passive preamplifier. It is almost like a tone-control. I read an interesting article many years ago that suggested that there is a see-saw inverse relationship between the bass and treble; add more bass and the treble seems to lose some of its sparkle, add more treble and the bass seems to lose its role of creating the music’s foundation. I find that this equation proves quite true with this set-up. Still, there is some wiggle-room. I can add just a little more bass when I want it, or a little less and achieve a perfect match for any music without canceling out the perception of the lowest bass or highest treble the current set-up can deliver.
The cost of these 2 purchases, around $2500 each, is over $5000, and does not reflect why many of us were originally so intrigued and attracted by the inexpensive entry point of a DIY Open Baffle solution as a serious approach toward one’s audio and musical dreams. What prompted me to spend the money was a feeling that I have reached an age where I want to live with audio products that I truly love; love for their design philosophy, their looks, as well as their performance potential. I get just as much pleasure looking at the Lowthers and Yammie amplifier as I do to listening to the gorgeous music they help to bring into my life. Also, the thought that the Yammie is performing its amplifier role with just 2 watts is still hard to believe, and is a source of delicious bewilderment.
One thing I was hoping for before I purchased the new amp and drivers is that it would be capable of resolving small scale instrumental music, like string quartets. I am happy to say that it succeeds beautifully, the strings have a sweetness usually missing from many audio systems that tend to harden the sound of bowed violins, making them sound brittle, and so lose the lovely subtle harmonic resonance that a bow sliding across the taught strings of a violin, cello or bass can create.
Our musical experience has now leaped from sounding reasonably good to sounding other-worldly thanks in a large measure to Spotify. And it may be interesting to note that the equipment used to feed the Maggies the day Deborah and I auditioned them, was well above $15,000, and that was without the cost of the Maggies themselves.
So-called hi-end commercial speakers and amplifiers that tout their pedigree and are offered at astronomical prices cannot deliver more music satisfaction then I am currently hearing with our relatively modest DIY Open Baffle system. Our current system is the result of what I have learned from playing around with the Open Baffle paradigm for several years, including the shared experiences of our wonderful community in this AudioCircle open baffle chat room, and of course, just simple luck. I cannot express the fun and enjoyment at having been able to slip out of the addiction of purchasing commercial speakers, with their carefully crafted illusion that one must spend more in order to achieve higher performance. I cringe to think what hi-end equipment with the added cost of a dealers mark-up would get for a set-up that sounds this good.
I am now wondering what further performance enhancements could be achieved using Tidal, with its lossless streaming format, or one of the other new high-resolution streaming services, and a well-designed, although not expensive DAC. Perhaps the soon to be released Aurilic Aries Mini at $400? To say that we DIY Open Baffle speaker enthusiasts are lucky to be alive right now, with incredible audio products and high-resolution streaming music services, is an understatement.
I photographed Deborah standing next to the new baffles for scale. Their new modest size is surprisingly able to penetrate the room with an immediacy and richness that makes people ask when they visit us, "where is the sound coming from.” When I point to the Open Baffle panels they look at them in disbelief, “the sound seems to fill the room and be everywhere”, one of our friends suggested.
Happy listening. If things change for the better I will keep you updated, just for the fun of it. With Warmest Friendship ~ Richard