THE MARCHAND TUBE CROSSOVER
It is always better to do it in the front than the
A LOWTHERESQUE INSIGHT
Let me explain in the simplist terms the current fascination with Lowther drivers, which uses no crossover....their musical magic is directly related to the absence of any crossovers, because passive crossovers choke off the dynamism and clarity of all speaker/amplifier interfacing. The combination of Lowthers very high effeciency (plus 100db), Alnico magnets and the lack of passive crossovers alchemize to create a completely unique experience that is shaking the audio orthodoxy. Audiomaniacs are hearing for the first time what happens to music when there is nothing between the amplifier and the loudspeaker to interfer with the transfer of the electrical signal to the driver, and when they go back and listen to normal speakers it sounds like someone put the brakes on their drivers, and they are right. This doesnt mean that the Lowther drivers dont have a package of eccentricies that may make them unacceptable for many...because they do...and they need a special breed of amplifiers to stimulate their magic....but the point is you should experience them to get the drift of where I am taking you....it is into the heart of loudspeaker darkness.
DO ALL YOUR FILTRATION IN FRONT OF YOUR AMPLIFIER NOT THE REAR
This is the most ancient wisdom which existed long before I was born. Any time we do our speaker filtering before the amp, rather than after the amp we create the otpimal interface between driver and amplifier output stage, and I would like just one person to argue with that. This means lower IM distortion, better transient response, and increased dynamics. Those of you who are in the pro business know just how SOP this is, with the big news being powered mini-monitors, with their own built in electronic crossovers, and at least two dedicated and sometimes three dedicated amplifiers. This is the only case I can think of where the consumer market is behind the pro market. Unfortuneatly almost all of these pro-speakers are festered with razor blade harmonics from their cheap transitor amps....but the idea is right on.
As far as I know the Marchand is the only tube crossover available in America, and it is made by Phil Marchand. (The only other unit is designed by Joe Curcio and it is available only as a kit). The only down side to this crossover is that it is a two way unit, and I wish Phil would consider making a three way unit. My old Lux tube crossover hasnt been available for years, but can probably be found used, but there is a real benefit in the Marchand unit, and that is its enormous range of options, within its limitations as a two way unit. You can, by simply changing plug-in cards, choose 6,12,18 or 24 db slopes, and if you choose the 6 and 12 db configurations you can also add notch filters. When used with my Tannoy horns I can employ the necessary 3.2k tweeter notch filter and the 280 hz horn notch filter, and completely eliminate the heavy avoir du pois of inductors and capacitors (all dual concentric speakers require notch filters) that are normally used to accomplish this. For an audiomaniac that has been committed to electronic, not passive crossovers, for almost three decades, Marchand delivers what I need. Like listening to the Lowther driver, the first time you hear your system with a tube crossover you will be disoriented.
But the most important benefit of an electronic crossover reflects back to the wisdom of Mike VansEver, and what I have been ranting about in terms of the absolute necessity of you having ultimate control over your systems tone, and that is a capability you gain with electronic crossovers. You can experiment with crossover points, slopes and filters. Why is this necessary and valuable? Because of the way your speaker interacts with your amplifier and your room and its furniture, and cables and everything else you have in your system.
But now lets turn it up a notch...and this is where we leave everyone in our dust...we can choose exactly the right amplfiers for each driver. The optimal woofer amp for the woofer and optimal tweeter amp for the tweeter. This is especially exciting for single-ended fanatics because, once relieved of woofer duty, your SET will optimally perform. With the coming of age of the 2A3 in America you can begin to experience combinations of 300B on woofers and this tube on tweeters. In Japan the conventional wisdom is push/pull on woofers, SET on midrange and tweeters. Others prefer combination of OTLs. But the most important facts of life here are, that once you use a tube crossover your amplifiers are so much more effecient that you can, and should, use much lower powered amplfiers...meaning they will be more refined.
The Marchand tube cross over has permitted me to explore the soul of my Tannoy horsn in a way that is impossible when I am connected to its passive crossovers. Or I can put that another way...without this crossover, I would not know just how good these speakers are, and you will be able to say the same thing about yours.
Let me throw down the lillac gauntlet and assert that power cords, cables, tip toes, Shun Mook discs or whatever is low level weeny tuning compared to a high quality electronic crossovers. Simply having the ability to alter the relative balance of the drivers is humongous benefit.
Phil Marchand is very excited that he can achieve 24 db phase coherent crossover slopes, which always takes a warehouse of capacitors and inductors to acheive with passive crossovers. This will make some go gah gah, but personally I dont like the way they sound, though I heard what they do. I prefer 6 and 12 db slopes, and gladly pay the price for using them...you pays the price no matter which way you go...but remember it is your choice, and tomorrow you can change your mind, because you have all of the filter cards needed to choose any slope or frequency you want. I have about twenty different cards, and nothing is more fun than smoking a cigar, drinking some champagne and tweaking my speakers with different cards.
Now let me discuss the Karma Sutra of tubes, which is the process of exploring the subtle eroticism of different tubes. This form of eroticism is the highest expression of the thermionic soul seeking transcendance, and a task that requires the most intimate relationship between the triology of life....the gifted listener, the triode amplifier and driver, and your conclusion should be obvious...a tube crossover is needed for exploring the most subtle pleasures of music.
RADICAL MINI-MONITOR STRATEGY
So you want to have fun? You are feeling restless, and want to explore the deep, rich veins of your musical soul...and you have small living room and your not Donald Trump.
My recent experience with auditioning mini-monitors stimulated this radical and way cool strategy to satisfy the fires burning in your musical soul. This is what you need:
1. High quality 2 way mini-monitors
All that you have to do is remove the passive crossover from you mini-monitors and use your tube crossover and you will reach a significantly higher plateau of musical pleasure qua intimacy. I have also asserted repeatedly that two small, less expensive amplifiers, used with a tube crossover, will give better results than one more expensive amplifier used with a passive crossover.
With your space limitation this means that you can have endless hours of fun and not be burdened by yardage of electronics...and this means that under most circumstances with your 300B single-ended amplifier connnected to the woofer of your mini speaker it will be positively ejaculartory in its transistent response...and you can use a 2A3 amplifier on the tweeters because you will never need more than a fraction of a watt for them. Get my drift sailor?
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