February 2015

The Magtech Monoblock Amplifier

The Godzilla Brothers do Some German Twins

Francis Vale


The review starts with the security forces at my front door.

But I digress. 

Back in time we must, some months ago, when electron dementia came running up unexpectedly from behind and whacked both of my two Sunfire Signature amplifiers. These stereo amps can breakdance 1,250 watts/channel at 4 ohms. But in my setup, each Sunfire was acting like a monoblock amp, one per each OMG, MBL101D speaker. These German-made speakers radiate fully circular sound (MBL calls this omnidirectional loudspeaker a “Radialstrahler”). My Sunfire twins had been belting out the round wattage for more than thirteen years when their mindless humming set in.

Now what? A loser amp would be stiletto heeled by these demanding Deutschland Divas. It made for a short list of electrical dates.

I did a Must Love Germans for dating some replacement watts. MBL was busy touting its new Corona amplifier line… “The ideal fusion of high end sound & and innovative design concept.”  The line’s C15 monoblocks specs were attractive, even their cosmetics were good. They were sans heat sink skirts due to a trendy class-D output stage design and chill to thermal stress. Each fashionista was rated at 500W at 4 ohms.  But word was that it’s only 480W for improved sound. This pair of electrified Germans was also demanding $25,000 for carrying the 101D loads up and down the musical scales. Even though these were fine amps, it seemed to me that Class D movers shouldn’t be charging that much to haul my sonic freight.

Then I was told about Musical Fidelity’s new M8-500s stereo amplifier, a fully balanced design rated at 500 Watts per channel into 8 Ohms, and almost 1,000 W into 4 Ohms. The MF tag line pulled at me, “The M8-500s can drive just about any loudspeaker you choose.“ And then there was the Amazon price, just $6,999; 28% of what MBL was charging for its C15. Finally, MF is Antony Michaelson’s company, a musical mensch with a long history of turning out no bull products that hit way above their price weight. So, yes, please, sign me up for a review unit.

And so it came.  Its 64 pounds of mighty British wattage were quickly wrestled out of the shipping box, plopped into place, hooked up to the MBL 101D’s, and then, and then, WTF?

The MBL’s were squeaking skinny distorted sounds. They were being starved for juice. The two Germans rose up against their new UK/AC master.

Desperate for a musical truce I changed the cables, the preamps, the input sources, and still got this weirdly out of shape sound. I double and triple checked all the amp and speaker connections, made sure all the M8-500s switches were in the correct position for RCA interconnects, but all were OK.

I was done to the arcane. When setting things up I had swapped out the M8-500s OEM power cord with a high-end AC cord. Could it be? Unlikely, as this AC cord has been a consistent star performer. To be certain, I tried other vendors’ high-end power cords, all of which had successfully assisted different amps—same distortion disaster.

I noticed that all these other AC cords had ground plugs, but the MF cord did not. In the event, my floating an amplifier ground with an AC cheater plug could just be punting any serious electrical problems onto the interconnect wires, never the best idea. All hope lost, I despairingly plugged back in the original AC cord. Everything was suddenly peachy keen. Aye! I was trapped in the belly of that indeterminate reality beast, the electron Wave-Particle Duality. All manifold possibilities of these AC electrons were determinedly collapsing into a state solely intended to quantum mess with my reviewer certainty.

What should have taken no more than 30 minutes for system set up had now consumed many backbreaking hours. The M8-500s and its OEM power cord sure sounded nice, though. But, MF abruptly asked for its amp back before I could do a proper audition. Apparently MF can’t handle Herr Heisenberg injecting any uncertainty into reviews of its products.

But I digress.

I sat in scrunched sorrow in the den, pondering my miserable audible lot, listening to my Analysis Omega full range ribbon speakers, hoping for sonic salvation. I noticed the Magtech stereo amp powering them. This amp is a mighty affair, effortlessly driving the Omega’s, and with total musical finesse and control. I sprang up and immediately checked out the website for Sanders Sound System, the Magtech maker, and lo, “The Sanders Sound Systems Magtech amp is now available as a Monoblock power amplifier. Performance is similar to the Magtech amplifier with the exception of dramatically increased power output capability!” Huzzah!

Each monoblock was awesomely rated at 1600 watts RMS into an 8 ohm load, and an over the top 2000 watts RMS into 4 ohms. Their price was equally incredible, $11,000 for the pair—way less than those two MBL C15 monoblocks. Oh, do come to papa do. And they did.

Like their stereo sibling, the Magtech monoblocks benefit from innovative electrical design. Rather than lousing up the technicalities let’s directly quote Sanders:

“Amplifiers operate at much higher voltages and currents than line level source components.  These higher voltages and currents forces conventional regulator designs to waste large amounts of energy, which wastes expensive electricity and causes the amplifier to get very hot.  Also, many regulator designs radiate RF (Radio Frequency) energy when switching high currents and voltages.  This RF gets into the amplifier's electronics and can cause instability, oscillation, and noise. As a result of these problems, modern power amplifiers do not use regulated power supplies and fail to take advantage of the benefits available from doing so.” 

“Sanders has solved these problems by developing a voltage regulator that is essentially 100% efficient.  There is no heat dissipated by the regulator system.  There is no high-power/high-voltage switching that causes heat generation or RF problems. The regulator in the Magtech amplifier maintains a stable voltage regardless of load or reasonable changes in the line voltage feeding the amplifier.  It runs stone cold, produces zero RF energy, and is simple and reliable. Unlike other amplifiers, the distortion in the Magtech amplifier is virtually unchanged regardless of power level.  The bias is stable regardless of load.”


I perversely attempted being whacked again by the mercurial electron fates. Once more I used the same high end power cords. But the MBL’s just wrapped their limbs around the Magtech monoblocks in musical ecstasy. Despite the heat of the melodious moment the monoblocks stayed cool, even when, as Sanders advises, left continuously powered on.

But what’s this I hear? Located immediately below the 101D’s omni woofer wonder is a 12" cone subwoofer. It’s housed in a dual ported, conventional cabinet. On deep bass notes both speakers’ subwoofers were emitting low-level chuffing noises out their front ports. On the other hand, the rest of the sound was clean and prodigious.

Clueless, I let the Magtech blocks and the MBL’s go about their musical mating dance in undisturbed privacy. Their high wattage tango went on for almost three months, when wham! The two MBL subwoofers suddenly burst forth into full-throated roars of approval.

Conceivably, but hard to fathom, my more than ten year old MBL’s and their subwoofers could just now have been breaking in. The Sunfire amps were good. But maybe they didn’t have the AC sac to grab these subwoofer mothers by their baskets and forcibly drag them down into the Stygian depths. Then again, maybe it was the strapping monoblocks needing extra time for their electrical ligaments to limber up. Then again, who the hell knows?

Whatever, it was time to start reviewing. I live in a high-rise apartment building, which has old school, solid concrete construction. But someone standing outside would have seen its cement sides buckling when I played Tracy Lorde’s “Pure Heroine”. The “Buzz Cut Season” and “Tennis Court” tracks were unleashing bazooka bass volleys. My apartment became an acoustically shelled seaport, towering sonic waves pummeling skulls and vulnerable bric-a-brac.

The 101D’s omni tweeter and its unique carbon-fiber petals also fully blossomed. High octave pollen swarmed the room while Bela Fleck jammed with V.M. Bhatt and Jie-Ben Chen on the “Tabula Rasa” album from Water Lily Acoustics.

The 101D was always an aspiring Houdini. The speaker conjured musical ghosts desperately wanting to flesh and blood materialize, never quite achieving it. But with its three, 360 degree firing drivers—tweeter, midrange, and woofer—producing solidly sculpted sound was not easily found in the MBL rabbit hat. Performers were always a bit fuller, a bit harder to nail down around the edges.  And yet even here the Magtech monoblocks worked some spectral magic.

I often found myself rushing into the MBL occupied room to see who had just
B & E’d my crib. Newly unmasked performers would just square me in the eye. They forced me to sit down at sonic gunpoint. They made me pay musical attention to what they had to say. 

Before, MBL’s stereo soundstage was tantalizingly close to sounding holographic. But the soundstage was now a sensory VR experience. The room also got virtually bigger. The Magtech amps would mightily heave on the speaker back wall, collapsing it. Newly freed artists could be joyously heard as they emerged from their broken plaster jail. 

Well-recorded pianos are huge and hungry beasts. Given the chance they will chew up your whole room. The Magtech monoblocks opened the larder. The 101D’s and Magtech’s invited George Winston into the house, sat him down at his piano, and turned him loose on “Montana: A Love Story.”  His was a real piano, in a real performance, set in a soundstage that extended way off into the Western sky.

The transformed soundstage was accompanied by significantly enhanced transparency and detail. Everything you thought you knew about your recordings was a false memory, implanted by alien electronics. The Magtech monoblocks reveled in revealing new musical universes. Check out the score to the 1959 movie, “The 3 Worlds of Gulliver,” composed by Bernard Herrmann. It’s a rollicking foreign landscape and your acoustical passport is the Magtech.

Sometimes it got spooky, like on Andreas Vollenweider’s Book of Roses album. It has a track that opens with chalk scratching down hard on a blackboard. When I next looked up I fully expected to see G clef graffiti scrawled across my living room walls.

I also played Ry Cooder's and Ali Farka Toure's Talking Timbuktu album, which won a Grammy in 1994. A group of previously lost in the background people suddenly leaped over the electron fence and scrambled into my room: “Mogo do min bε angilekan men be yan, wa?” I called the INS.

Happily, there was no such scratching and scrambling with female vocals and strings. They were rendered astonishingly present and freshly supple. Hello Ms. Fitzgerald, hello Ms. Carter, nice to at last completely make both your acquaintances.

But, on some source material there was still an exaggerated bloom to the deep boom. It was especially noticeable while listening to Sirius XM radio.  (Its curated jazz channel is especially good.) The Sirius XM signal is heavily compressed. So I chalked up the occasional boominess up to a compression quirk. But such subwoofer quirkiness suddenly devolved into the mentally deranged.

For the first time in almost a decade of my living in the building some tenant had complained about loud music. But my music wasn’t. Still, here were the building’s security police knocking at my door. They couldn’t even identify where the sound was coming from on my floor. They had to walk right up to my door to locate the source. My unchastened MBL’s just glared back at them and refused to assume the face down music position.

The security police said OK; the music was not that loud. But maybe the bass was too strong. Sure enough, Sirius XM jazz was playing, and there was that exaggerated bass again. Images of sonic termites nibbling away at my building’s steel foundations munched into my thoughts.

Security's tenant-appeasing suggestion was to raise the speakers a bit off the floor.  That might keep the big bad MBL woof from madly coursing the concrete and steel woods and hunting down this unsettled neighbor. So I did, with Black Diamond Racing cones. As a bonus, the bass was also tighter. I probably should have done this cone hack a long time ago. But I was put off by nervous thoughts of losing a Torikumi with the massively heavy MBL’s.

Then badly handwritten notes began appearing on tenant mailboxes in the building lobby. They were posted around mailboxes near mine. These were unrequited musical ransom demands. The messages raved, “Despite all my complaints you still don’t have the decency to turn down your music in the morning!”  Apparently, the selfsame tenant who called the heat down on me was also targeting other people living in the vicinity of my apartment for their sin of music. My skin crawled.

A week later, I again turned on Sirius XM jazz in the evening.  Once more I puzzled over the woolly bass. The volume had also been left a bit too high for evening play so I immediately turned it down. Not more than five minutes had passed since my fingers left the volume knob than building security police were once again knocking at my door. 

How was such a fast and furious tenant response possible?

About two weeks after this last security visit me and two of my next door neighbors were riding together in the elevator, ascending to our floor. One of them abruptly turned to me and asked, “Was that you who posted a note on my front door complaining about the TV being too loud?” The third tenant then chimed in with his own recent and similarly unsettling experiences. Shit! We were all being stalked.

A one-person tenant terror patrol was roaming our building corridors. And he (or she) was pressing their maddened ear against people’s front doors, silencing orange jump suit perhaps in hand. How far would executing his audio fatwa take him? I spoke to building management. They checked their security call records.  Yes, this was a real problem.

Two months later, I was told this audibly gruesome Grinch, whoever it was, had left, perhaps with strong encouragement by building management.

Nothing exists in isolation, including audio gear. The musical abstractions they produce cause highly tangible effects, good and bad. For some in this world The Absolute Sound can only mean The Absolute Silence; of which there is only one terrible kind, Requiescat in Pace, Harry Pearson.

Another and mercifully uneventful month went past, and the sloppy bass on Sirius XM finally cleaned itself up. The Magtech makeover was complete.

And now I no longer digress.

I had to wait almost six months for the MBL 101D speakers and the Magtech monoblocks to settle down and happily live together. I had never encountered such a lengthy time for amplifier break-in; usually, I see this with new speakers. Apparently, Magtech electron nanobots had been busily interior remodeling my MBL’s. When their unseen handiwork was finished I was left with an essentially new and quite wonderful system.

The Magtech monoblocks are enormous electron pumps with bottomless reservoirs of effortless watts. True to form, they puffed and puffed up the 101D’s skirt until the speaker was forced to reveal some sonic holes in its German made panties. Mostly, this design embarrassment was all about trying to seamlessly steady a big stack of omni radiators atop a conventional cone head. The 101D sub never could quite pull off this acoustic balancing act. On several recordings the discontinuity between the 12” cone sub and the omni woofer was clearly discernible. Neither component could apparently make up its mind about who was going to shoulder the heavy bass load.

The new MBL 101E Mk.II model rectifies these 101D design problems. The 101E Mk.II superficially looks like the 101D, but closer inspection shows it is a complete redesign. Yet, it still remains true to its Radialstrahler/omnidirectional design brief. In addition to a massive overhaul of the problematic subwoofer bits, the omni parts also came in for renovation, including revisions to the omni woofer, midrange and tweeter, and for good measure to the crossover network, as well. MBL is always on full kamikaze attack for audio perfection.

Does that mean the 101D is flawed crap? No, not at all, for whatever may be the 101D’s shortcomings they are still audio paragons, with few peers even today.

The big takeaway is that Sanders is really on to something with its innovative circuit design. Whether it is the Magtech stereo amp I use with the Analysis Omega’s, or the Magtech monoblocks driving the MBL 101D’s these Sanders products never cease to amaze. That they also cost much less than other high-end amplifiers is just a bonus. They will drive anything you got and never lose their cool, figuratively and literally.

Spend your money instead on bigger and better speakers. Sit back, listen, and feel very pleased about your newfound Magtech wisdom.


21st, The VXM Network,