Action A100T Synthesis in the Test

Tubes must not be squeamish. If an amplifier like the synthesis equal eight KT66 brings you can let it RIP really. And even without any THD Schmuddelei!

As the author of these lines recently entered the hearing room, he could not decide what shone stronger: the eyes of colleagues Johannes Maier, who had just listened to her or the eight KT66 tubes in the output stage of the synthesis action A100T. The force of the KT66 in mind churned, visibly stirred colleagues in mind, was already clear, what one had to expect Italy of this 40-kilogram colossus out. Power and glory with a skillful portion THD hot. And don’t forget: a stress test for ears and speakers. Because if the estimated colleague like an amplifier, it is usually really loud. And he liked this seems especially after his warmup.

In the run-up to the action-hero let: the manufacturer promises 100 watts RMS into 6 ohms – a real value of dream in the tube world. The excess of this performance is made possible by four KT66 per channel, circuit, so, used in ultra linear – with a screen grid feedback via transformer tap used. The power pentodes proved themselves once in the legendary quad II from 1952, which had to however make per channel stuck with a single pair of power piston.

Synthesis action A100T: Construction

So as then also at the A100T on the KT66 was chosen, because its output resistance (22 kilo) exactly harmonises with the output transformer designed specifically for this amp. Less scrupulous producers – ohm, ohm – certainly the more popular KT 88 taken.

The Italians, who founded her company with the construction of transformers for Guitar amps , expose the transformer iron cores for the A100T not only with words, highest linearity and bandwidth. The heating of the tubes with stabilized DC voltage promises to push hum to an absolute minimum. To control the output level synthesis uses the usual ECC82 and 83.

Or not the usual: all tubes go through at the final selection a two-step heating process, to keep the impact of quality fluctuations on the sound really as low as possible. The particularly stiff, H-shaped chassis also helps element to hold of the power and output transformers with its stability of fidelity.

In addition to tube nostalgia of the Italian manufacturer quite current accents: the housing while boasting generous use of brushed aluminum, but absolutely timeless elegant. The solid, machined from the solid feet and the remote control synthesis relies on the use of State of the art CNC milling. But computer technology plays a role not only in the production of the Action A100T.

Also when playing the integrated amplifier works with the PC. With its USB port, the device takes over the tasks of an external sound card. Which focuses on two are at least those comparatively rare, Wolfson D / A-converter type WM8740 24 bit / 196 kHz resolution used in dual – mono configuration. The A100T via coaxial S/PDIF input in the service of ordinary CD Player provides this converter.

Hearing test

In the listening test, the Fiery Italian showed a highly solid performance. And he got right down to business. We could save us in this power-potent muscle man the usual foreplay with trawling through the speakers camp for suitable boxes and usually following experimenting around. The action A100T took what was used before him, that’s extremely Picky KEF reference 207/2 was that in the bass range, or to the Sonics Allegra II.

Who connects so far lukewarm candlelight idyll with audiophile recordings with tubes on which an artist on an acoustic guitar or harp around then preferably plucks, have to listen to be sure this hot-blooded, powerful and broadband Ferrari of the Tube amps. Rock, jazz or Funk experience right in front of the stage left with him. Fed up, crisp, contoured (even in the low bass) emotionally, three-dimensional. Sound body cult instead of flat head burden. That went with the right music – some “heads up” from the Stanley Clarke Band – directly below the belt.

The A100T sparked no storm in a teacup, rushing up a storm. The music came up to the tester. Where strong transistor power stations from German lands such as the formidable T + A PA 3000 HV comparatively uninvolved in the steno style happening inform, who reveled in the soft clippende Italians such as Fellini in opulent, colorful, but nevertheless neutral sound images.

The hum of the guitar in “Fulani” came as authentic and vivid over the rock tube, as it can be experienced only in Natura. For me, as a tranny may be more accurate and honest. It brings but not this not Live atmosphere over there. It may sound contradictory, but who himself is listening, feel at once, what is real.