Egg-Shell Prestige 9WST REVIEW

Below we present the review of our tube vacuum amplifier Egg-Shell Prestige 9WST. The original article was published on the Polish site “Stereo & Colorful – Underground“.


The original text (in Polish) with pictures,
written by Ludwik Hegel can be found here:


Vacuum tube integrated audio amplifier

Egg-Shell Prestige 9WST




During my last visit to some familiar to me audio saloon in Gdansk I was pointed by the staff to their new acquisition: Egg-Shell amplifier, without revealing its country of origin. I thought that it must had been Italian again well known for their lovely design who released some new, interesting line range of tube amplifiers. Soon it occurred that this lovely Egg-Shell is being produced in Poland, in southern town of Bielsko-Biala. Amazing and encouraging phenomenon.

This visit and meeting Egg-Shell soon resulted in contacting the manufacturer, and after few days and one phone call to Mr. Krzysztof Grabowski from Encore 7 the brand new 9WST tube amplifier was in my audio room enjoying my both hearing and sight senses.

Encore Seven

Encore 7 is the manufacturer of Egg-Shell tube amplifiers from Bielsko-Biala. Behind the name there are two brothers: Andrzej, a great enthusiast and connoisseur of tube technology and Krzysztof, brand manager.

As one can read on their website Grabowski brothers’ adventure with audio tube constructions reaches back to the 90s when in the basement of their home the first constructions were created, up till 2010 these were mainly tube guitar amplifiers and audio amplifiers, mostly for narrow circle of close friends. In 2010 the regular company was established under the name of Encore 7. Two first models were introduced and they got little intriguing and enigmatic name Egg-Shell Prestige. With the help of professional design studio they created very unique visual project aiming to look completely different than any other tube amplifier on the market.

Nowadays, Encore 7 offers two tube audio amplifiers: Egg-shell Prestige 15WS and 9WST and various kinds of guitar amplifiers (on individual request). 15WS and 9WST differ only in terms of output power (2x9W and 2x15W) as the cases are identical. Also the 9WST has got the electron tubes base AC.

It is possible to order different variations of both case colour and the front glass. On special request the producer offers case vinyl decoration or special incisions. I have got 9WST Albino model (white case and lime front glass).

Construction and general impression

As I stated at the beginning the look of Egg-Shell Prestige is very intriguing and needless to say – beautiful. Its design brings connotations with Italian industrial design school: elegant mass-simple yet impressive. And that what Egg-Shell is like: big Woodwind© case with rounded edges on the sides (up and bottom). Side walls are piano black finished MDF. Front is made of tempered glass (available in several shades). Rest of the case is made of brass. Top cover is magnetic mounted; it is very easy to remove and it can give access to the tubes or provide better ventilation if necessary. I have to admit it is excellent solution, no fuss with screws etc., one move and the top of the case is off (or back on). Inside of the case there is a mirror like mounting plate, dented in a fancy shape that provides not only multiple mirror images of lamps but also works as the support for V-mounted power tubes. Other tubes are placed on the edge of the front sheet, just behind the glass. I can assure that thanks to that placement of tubes (and mirror brass) visual effect is very intriguing, especially in the dark room. Fantastic.

Quite original and unusual is the volume adjustment-it it quite big (wooden?) wheel which is extended horizontally in the middle (and below) the glass front. Funny to operate.

Source selector is the metal knob above the volume wheel, the selected source (3 available) is indicated by corresponding red LED at the left side of glass panel. In the middle of the front cover there is little Egg-Shell logo.

At the back of the case there are 2 single speaker terminals – separate for 4 and 8Ohm, mains, two fuse boxes and 3 pairs of RCA inputs. At the bottom of the case there are 4 hard plastic, rounded feet. On the right, bottom side there is two-stage power switch – not very ergonomic place.

What’s important the producer uses only tubes from widely recognized producers such as Tung-Sol, Sovtek, Svetlana (S), Electro-Harmonix (including the Gold line) and other available on request. Encore7 don’t reveal construction details however they assure that it is based on established and proven solutions. But certainly, all internal connections are made using the classic “point to point” method – there are no printed circuit boards inside.

Amplifier weights app 20kg, dimensions: 40x39x19cm (w, d, h). It comes with 24 months warranty.

Egg-Shell 9WST costs about 8 000 PLN, but with its original design and attention to details it makes impression of much more expensive brands, from the edge of luxury segment.

Sound experience

The way it sounds can be described very simply and briefly; it sound the way it looks – beautifully and originally. Strikingly. Certainly, this is an advanced level of sound, full of nuances, reverbs, while subtlety. The sound delivery is very saturated, thick and juicy. Abundant. However, it is a healthy tone – harmonious and well balanced, very nice sound, sophisticated color, if such epithets can be used to describe the sound.

Egg-Shell Prestige 9WST produces just 9 watts power per channel, so I connected first set of speakers with a little hesitance, especially because it were Gradient Helsinki 1.5 with the effectiveness of only 86 dB. I quickly found out that the amplifier “was able” or properly controlling Finnish speakers. At the same time it gave a beautiful vocal color, revealing the complexity and micro-dynamics. A phenomenal deal. However, the overall sound was a bit lean, you could feel that the amp was struggling a bit and the columns do not give all they have, and especially at higher volume levels the sound lacked of mass both in emission and in low tones.

So for sound quality sake I decided to connect only 90+ dB speakers. It were as follows: Vienna Acoustic Mozart Grand (90 dB effectiveness), Rega RS1 (90 dB) and Martin Logan Motion 15 (92 dB). And such set proved to be the most optimal and efficient for excellence sound and its saturated nature.

Egg- Shell offers colorful and artistic communication and the sound is very well distributed in space – and it has the consistency and it is filled mass that provides roundness of sound and density. With “roundness of sound” I mean a nice ability to generate sound closest to physically delivered, such as a close concert – with a clear beat and a spectacular overall density of the media, which is a bit hazy at the edges, giving the impression not only of full of depth, but also gives a sense of strong tangibility notes. It is worth noting that low tones are energetic and wonderfully firm, which also fits well with the characteristics of the overall sound, which is perceived as complementary, well-composed and well-placed. The instruments and vocals are beautifully extracted from the background. The scene that sound builds is deep and wide, vertically and horizontally, and tangible with sense of holography. True and real.

What’s interesting despite the output power of only 2x9Watt the amplifier has no problem with properly controlling the speakers I have used during the tests – the volumes and the overall dynamics rate is high. The control of rhythm, escalation and extinguishing of the signal and creating a wall of sound is extremely satisfactory. This is a big (and surprising) advantage of amplifier from Bielsko-Biala.

One could spend much more time writing about the qualities and benefits of Bielsko-Biala amps, but I think that’s enough. It’s just a pure high-fidelity. These are the amplifiers with very high-end quality. The Egg-Shell Prestige 9WST delivers the sound of maturity and sophistication. It can be compared to a vacuum tube devices like Leben or Cary Audio – a similar class elegant and sophisticated style sound.

Yes dear reader, the amplifier we described here is simply outstanding and the value you are getting for the money out of competition. Several times while listening to it I had the feeling of using the few if not teen times more pricier equipment.


  • Egg-Shell Prestige 9WST is of an original design-and not just for a tube amplifier, but generally as a sound reproduction device. The project proposed by the Bielsko-Biala company has surprisingly mature idea of manufacturing construction that combines the elements of glass and steel. Also the placement of electron tube is unusual: not upright (as usual) but in the V shape. Installation of lights accompanied by metal mirror interior enhances the viewing experience.
  • Amplifier offers a very solid construction and very intricate finishing touches. The volume wheel is quite interested – it is the horizontal circle of relatively large diameter protruding slightly from the front. It is possible to adorn the case with printed graphics or engraved top cover (mounted on magnets).
  • The sound is very extensive and surprisingly spacious for a power of 2 x 9 watts. And dynamic. It offers vivid and nuanced communication with plenty of space and a high specific quality, saturated with music. It is extremely racy and mature sound of high-fidelity class.
  • An amplifier low power is a limitation to a certain extent (see section 5), also the lack of accurate selectivity and sophisticated precision in passing micro-dynamic phenomena.
  • The amplifier has a power of 2 x 9 Watt so it makes sense to attach the columns on the effectiveness of 90+ dB to it. While testing I connected the speakers with a lower efficacy (Gradient Helsinki 1.5 – 86 dB), the sound was vivid and consistent with a beautiful, emotional vocals, but it was not quite full – you could feel the middle and upper volume insufficiency, especially in low ranges. The columns of 90+ dB offered the right momentum and freedom. And adequate power.
  • Egg-Shell Prestige 9WST is the Polish tube amplifier which has made huge impression on the author of this review – both visual and sound wise. Huge congratulations to the producer, Encore7 for the talent, the invention and the product in general. With such a little masterpiece as Egg-Shell I predict it a splendid career and I wish it with all my heart. Well done Encore Seven!

The equipment used during the test

Amplifiers: Hegel H100, Dayens Ampino, and set of the preamplifier and two mono power amplifiers Rotel RC-03/Rotel RB-03/Rotel RB- 03.

Columns: AudioSolutions Rhapsody 80, Gradient Helsinki 1.5, Martin Logan Motion 15, Vienna Acoustics Mozart Grand, Studio16 Hertz Canto Two, Rega RS1, and Usher S-520.

Digital sources: DVD Musical Fidelity A1 CD Pro, iPad 3 Apple and NuForce Air DAC.

Turntable: Clearaudio Emotion and Roksan Radius 5.2.

Phonostage: Ri- Audio PH -1.

Pickups: Goldring 2100, 2300 and Legacy, Audio -Technica AT-F3/III and Clearaudio Aurum Classic Wood.

Wiring: Audiomica Laboratory including the Pirop Reference, DC- Components and Nameless.

Accessories: acoustic panels Vicoustic Wave Wood (10 pieces) on the walls, anti-vibration base Rogoz-Audio 3SG40 under the turntable, anti-vibration feet BW40 Rogoz-Audio under the amplifier, RCA plugs Sevenrods Dust caps, and the power supply noise reducer DC-Blocker DCB1 of Tomanek.

Original: Ludwik Hegel
Translation: Susel

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