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When we heard the Tannoy Glenair for the first time, we had an immediate association with Gizmo who was fully into their dual-concentric virtues via his own -- of course heavily modified -- Tannoy Westminsters. During the first listening session with the Glennies, it was evident that these hi-sensitivity loudspeakers could really rock. Their huge cones were capable of putting out a substantial amount of decibels when fed the proper diet. With the Moscode, we could shake the cups out of the cupboard if so desired. As George Kay states in the accompanying literature, he focused a lot on getting bass reproduction right. Our favorite bass player for now is Frenchman Renaud Garcia Fons who proved the Moscode man right. The live version of Arcoluz contains many tracks with snapping bass transients and openly popped or bowed 40Hz strings of his monster 5-string upright. Renaud Garcia Fons often uses his bow as a drumstick on the strings and you should have seen the Glenairs' cones flex. The Moscode controlled everything without breaking a sweat even under high pressures. At non-party levels too, this combination behaved as though made for each other. The strong point clearly was how brilliantly the tonality of each instruments was expressed. Tannoy's paper cones, great wood work on its cabinets and the 401HR's own voicing matched up most wonderfully.
A completely different kind of loudspeaker animal was the Quad ESL 2905, the larger of the two latest models. It was quite the treat to combine two reincarnations of legendary audio equipment. Even though the ESL now has a far more acceptable impedance curve than the ones Gizmo used to play with when he was toiling with his Futterman OTL design, the voicing of the Quad remains the same. The first tones from the Moscode/Quad combination were sheer magic, not for misty-eyed nostalgic reasons but purely how music was presented. Though we did run the ESL once into overload protection when we pushed the pedal to the metal too hard, the combination proved to be very good. To avoid overpowering the ESL, a preamp of modest gain would be the preference on the Moscode 401HR. The Lamm wasn't ideal because its useful attenuation range was rather limited. A pair of Rothwell 10dB inline attenuators could have helped if we'd had 'em on hand at the time to lower the incoming DAC signal. Overall, the Moscode|Quad marriage with the Audio Note as preamp was blissful and it was mighty hard to let the 2905s return to their maker.

We were then asked to review the Mobile Fidelity OML-2 floorstander for a Dutch magazine. This budget-conscious ported two-way system was quite happy with the Moscode. We found the sound rather colored but not unpleasant though the Moscode's own special tonality was overruled and superseded by the OMLs. When we upgraded our Avantgarde Duo to Omega status, impedance rose to a whopping 17 ohms while sensitivity went to 107dB. One would assume that such high sensitivity isn't exactly a dream match for a 200wpc amplifier. Well, we connected the two nonetheless and were more than surprised. The urban legend has it that micro-powered DH SETs are the only serious ammunition for high-efficiency horns. Ahem - the legend should remain a legend. Direct-heated single-ended triodes are magic machines and in combination with horns can create sheer beauty. But don't rule out the beauty of unlimited power either. The Moscode proved to be a gentle giant, the beast that treated beauty with kid's gloves. In fact, the sound of the 401HR approached our 8wpc DH SET, albeit with huge balls. The Duo Omega could now shake the building under extreme dynamic peaks without losing any innate smoothness. In the all-important vocal band, the 401HR proved very SET-like on these speakers and rounded off smoothly in the extreme highs.

Albert von Schweikert's now renamed VR5-SE came to us with only a few hours of playing time. Even though the speakers had been to a few shows and thus chances for further run-in, they seemingly need 300 hours of full throttle punishment before coming to life. This requirement is hard to carry out when you live in an apartment building and want to stay there for a while longer. That review has thus been postponed until Albert delivers a properly seasoned pair.

From Paris came the Haliaetus Firebird for some playing time in our Rotterdam sand box. It is not the most sensitive speaker at 87dB but with 200 watts on hand, we suffered no shortage of power. With its trademark protruding aluminum nozzles that enhance the speaker's bass capabilities from its small 8-liter cabinet in combination with the hybrid amplifier, these modern creations were able to portray a realistic image of small and medium music formations. Gerardo Nuñez and Vicente Amigo's Flamenco with its fierce hand claps and strong vocals did very well.

Large orchestral tuttis were a bit beyond the Firebird's purview but to get such musical force parlayed convincingly is hard on any system. On Jazz Rock like that of the musically reincarnated Al di Meola or Mike Stern, the rocket science speakers however did well with the hybrid amplifier.

The last loudspeakers we were able to combine with the Harvey Rosenberg tribute was the Final 1000i. Final is a Dutch loudspeaker manufacturer who specializes in tall and narrow electrostatic transducers. Unique to Final and contrary to for instance Quad is their inverted drive scheme for the membranes. Their Inverter Technology applies the incoming signal not to the stators as conventional electrostats do but directly to the Mylar membrane. This allows for less expensive components and a simplified manufacturing process for more attractive pricing. An upcoming formal review will cover more details. With the Finals, we finally had a loudspeaker that truly required Moscode muscle.

All others could well live off a weaker amplifier but the Final 1000i with its dimensions of 199 x 36 x 5cm and rated at 86 dB/4-ohm loves current. It is also with this loudspeaker that we leashed up the Velodyne DD12 subwoofer in parallel, bananas over spades. This speaker combination now covered 20 to 20. Once again the Moscode was happy to provide whatever was needed.

Candidly, not a single loudspeaker managed to elicit one false note from the amp. Moreover, the Moscode prevailed throughout all marriages -- except for the Mobile Fidelity -- by retaining its own tonality, its very soul if you will that makes it a very pleasant machine. Those who seek a completely neutral wire-with-gain should pass on the Moscode and forever rest in piece. No tubes on their tomb stones for sure.

George Kaye designed this amplifier such that even when the driver tubes are changed, the typical Moscode sound remains. Driver tubes in a hybrid design are responsible for a great deal of the tonality but not all of it. Contrary to hybrid
designs that use transistor drivers and tube outputs, tubes as drivers offer far more control over the naturalness of the sound. When small triodes are used as drivers as in the Moscode, their capacity of linear voltage amplification is fundamental to achieving noise-free transparency. George relies on a very quiet, passively regulated filament power supply to achieve his very clear, detailed and open sound. Built like many preamplifiers, the Class-A input stage eschews all negative feedback. Only later in the circuit does the output from the first stage combine with negative feedback from the output to enter the follower stage which is capacitive coupled to the Mosfet power buffer. The tubes can drive the Mosfet directly, no intermediate transistors. The Mosfets are mere followers to the signal off the driver stage. To keep the Mosfets biased, George used an optically coupled circuitry in conjunction with a pair of film capacitors so the main 176.000 μF capacitors do not have to be used for this purpose. All this results in the very tube like top end the Moscode evinces.

Tube rolling as already mentioned is the main attraction of Moscode ownership. Flip open the front plate, change a pair of tubes -- glove provided so no nasty burns -- close the panel and after a few seconds, there's music with a slightly different attitude. When inserting the tubes, the sockets give a little because they are suspended. Even tubes with a center-tapped filament may be used. An auto filament switcher senses the center tap and switches from a standard 2-wire filament circuit to the 3-wire version so tubes from the 12-Volt series like 12AU7s may be used.

The small driver tubes usable can be divided into the low-mu/low-gain and medium-mu/higher-gain camps. The latter elicits higher negative feedback from the amp circuit. Generally speaking, a low-mu driver makes for a smoother sound with a slightly forward soundstage. Medium mu valves tighten the bass and deepen the stage. From our notes, the medium mu Svetlana 6N1P and Tesla E88CC SQ from the Prague factory (no. 32) resulted in a much more dynamic sound. Especially the Final electrostatics gained much to sound far more like 'real' electrostatic speakers with the 6N1Ps in use. Listening to Thierry 'Titi' Robin's live CD Anita became a real adventure, a tighter, richer and more full-bodied sound the result from the planars. Less forward and a little smoother was the verdict with the Tesla pair on the same speakers.

Low moosters like the Thermionic 12BH7 for voltage gain compared to a medium-mu valve netted more rounded middle frequencies and could thus be described as more musical - more wood, less metal. Using two pair of medium mu tubes like the 6N1P for voltage gain and the Tesla E88CC SQ as follower mellowed the forwardness of the 6N1P and increased warmth while retaining dynamics. Each and every permutation involving the tube/loudspeaker combination can result in eye openers, sheer blissfulness or revolting shivers when the combination isn't right. We spent some 200 valve Euros in total and had more than 10 times the fun. The Moscode hybrid is a real toy for a real man (who can of course be a woman as well).

In conclusion, the Moscode 401HR is the most tweakable, adaptable and thus funnest great-sounding amplifier presently available. It is neither neutral nor does it sound completely like a DH SET (nor like a big transistor or even switching amplifier). It sounds like a Moscode, period - powerful, fast and absolutely transparent. Summed up, this means this amp plays music and not merely sounds. Gizmo would be so proud if he could hear this legend reborn!