Let's see what happened when a more modest dynamic loudspeaker priced friendly and now just 92dB efficient took the 6-wagon SPEC train. This pulled in our Sounddeco F3 four-driver 3-ways again with the SGM 2015 and T+A DAC8 streaming source. Now there was zero residual hiss either in the listening seat or close up from the speakers. The power supply for the H-VC5 was still muffled by its blanket. Of course the volume setting had to be upped to match the SPL from the 10dB+ more efficient horns when returning to Blue Maqams. Already the first track revealed the organic and relaxed yet dynamically ample character of the amplifier set. These sonic components very much smacked of a live recording. With these more modest speakers in charge, the 'SPEC reality' of musical replay had a strong affinity with the live elements of music. With the Aaron Parks recording too, this sense was very notable. Setting aside notions of neutrality, transparency and other audiophile spear points, the sound was unmistakably musical and lacked any hints of artifice. For the latter decider, we often use Dire Straits' Brothers in Arms as an example that's overly clean and polished to a shine. With only a few simultaneous notes at a time, it does normally sound like a very mechanical thing.
Switching from neutral to sophisticated shifted the tonal character towards more sparkle and was very dependent on the recording, a bit like the effect variously shaped wine glasses have on the same stipple. Some fermented grape juice prefers a wider glass, others one more narrow.
Playing from the analogue domain again and switching between turntables and phono stages, the notion of listening to a live performance not too close to stage was potent. Even with apparently modest loudspeakers, the SPEC amplifiers did magic. We suspect superior phase integrity under dynamic conditions from what Banno-san points at when he explains how a loudspeaker's back EMF interferes with the power supplies of traditional power amps whereas the RPA-MG1000 maintains a stoic grip regardless.
That ability to absorb back EMF plus multiple types of tone wood for the enclosures, EMI/RFI-absorbent paints inside them, meticulous parts selection from very lengthy auditions, strict attention to the power supply and low-pass filter… they have all paid off in full. The RPA-MG1000 is a radical statement in itself, a de facto integrated which morphs solid state into tubes. We already mentioned our experience with the British Ongaku. By the end of our time with the SPEC set, we were completely convinced that this Japanese way of doing class D now utterly overshadows even the very best tube-based designs. That said, we do note a few points of criticism. First, the volume control and to be more specific, its cheesy power supply. SPEC put enormous efforts into the power supply for the actual amplifiers but shipped us the controller with a very noisy $5 SMPS. Next we would like to see the gain selector become a rotating knob to prevent accidental adjustments. Both issues already have Tsutomu Banno's attention and a solution is on its way. Presently the full set consists of six separate devices, two of which are clad in aluminum. While the power supplies and monos look gorgeous in their warm orange lacquer, the functional metal boxes are no match. How nice would it be for the controller to adopt the same finish, get a linear power supply and for both the volume controller and input selector to gain remote control?
Finally about those big numbers on the bill. Here we Dutch are supposed to be frugal. At first the asking price of €60K looks very steep instead, particular above that byline of class D. However, the RPA-MG1000 must sonically be compared to the very best tube monos available. We mentioned the €90K British Ongaku. Other amplifiers that might be in the same league as the SPEC could be a Silbatone P300, a Kondo Shinden at around €150K, an Audio Note GakuOn, Wavac H-833 or TruLife Reference all set to drain up to €250K from your bank account. Yet they all are puny fleas compared to the massive power which SPEC offer to really drive any speaker with, not just high-sensitivity horns. And don't forget that tubes have limited life spans and are highly inefficient in the energy thus green departments. That makes them give up even more brownie points. When on hand to enjoy the right perspective, €60K for a pair of amplifiers now isn't crazy and probably far more fun than driving a shiny Lexus in gridlock LA or Hong Kong traffic!
Postscript. Banno-san wanted us to know that as of mid April 2019, a volume controller to match the amplifier design was already in the prototype stage. It will have a better power supply. When that's in the can, they will start working on the input selector housing. Also, the gain slider will be replaced by a rotary selector.