Closer Acoustics 300B Provocateur Signature Adam Sztaba integrated amplifier

 300B Provocateur Signature Adam Sztaba - a pursuit of excellence.

The top of the line version of Provocateur that together with Vigo EX Adam Sztaba Signature makes a system approved and signed for sound quality by Polish musician, conductor and arranger Maestro Adam Sztaba. 

Closer Acoustics does not have many tube amplifiers in the offer. Only the 300B triode. And there is a reason for that. We are focused on having the best possible Single Ended Triode amplifier on that tube. Why this tube? Because in our opinion, and not only ours, it is the queen of tubes, designed and developed for amplifying sound almost a hundred years ago by an American company - Western Electric. A tube that when properly used can provide musical experience of the highest level. It is a low power tube, only 7 watts, and since our speakers have high efficiency - Vigo has 97 dB, it means that to be fully happy, it only needs those first few watts. But they must be of excellent quality. It's not quantity that counts, but quality. If everything is well composed, then we are rewarded with emotions and a message that squeeze tears and make shivers run down the body while listening to favorite music. There is dynamic range, energy, impact and detail. But for that to happen we need to provide the tube with the right conditions.

Let's start with output transformers, whose quality is of paramount importance for the sound of a tube amplifier. The Adam Sztaba Signature version sports two big amorphous core transformers (3kg each). The use of amorphous transformers reduces hysteresis and the influence of eddy currents on the frequency response, which has a direct impact on frequency response extension. Especially the high registers gain in clarity and purity of transmission. Increasing the cross section has an effect on the stability and foundation of the low frequencies.

In addition to upgrading the output (speaker) transformers, we increased the efficiency of the power supply circuit by using a 30% more powerful transformer, which allows even more efficient power delivery to the amplifier circuits. Of course, as you start altering the mechanics and changing the size of the components, consequently you have to modify the design. The new Provocateur consists of 34 internal design elements. In the case of the top Provocateur, all transformers have been "canned" to minimize interference.

We managed to keep the size of the amplifier when viewed from the top, but it had to grow slightly upwards to accommodate the transformers. Looking at the case from the outside, the increment is the bottom strip with embroidered lettering.

After transformers came the turn to capacitors and resistors. In the audio circuit we used some of the best - if not the best - audio capacitors currently manufactured in the world by an American company, V-Cap, ODAM series - reference-grade, specially selected with an accuracy of 1%. They offer unparalleled transparency, longevity and an unprecedented low noise level.

The resistors come from Kiwame, Ohmite and Amtrans. The former constitute the main element of the power supply circuit, Ohmite work in the cathodes of the 300B tubes, while the sensational carbon Amtrans of the AMRG series are used in the signal path.

Again, the consequence of changing the size and number of passive components was the need to redesign the circuit board... and since the new board had to accommodate the better class components, to improve the quality of the conductive paths they were gold plated and made on a thicker laminate.

The audio signal RCA inputs were upgraded to fine silver conductors from WBT nextgen series, as well as speaker pole terminals. We used the highest grade NCF power input socket from Furutech.

Finally, we modified the gain control a bit by using a Khozmo resistor ladder on relays with excellent quality Takman resistors. The ladder is remotely controlled, contains 64 positions, and has been calibrated by us to operate in a useful gain range from position one. Since good tube systems are characterized by the fact that you can enjoy listening at low volume in the evenings while enjoying good, full-bodied sound, being able to precisely adjust the volume at low levels is very important.

And the most important thing for us is customer satisfaction, because such a component is chosen very consciously to be enjoyed for life.

Technical specification