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INTEGRATED AMPLIFIER ⸜ tubed

Audio Reveal
JUNIOR

Manufacturer: ALTRONIK
Price (when reviewed): 13 900 PLN

Contact: MICHAŁ POSIEWKA
ul. Muszlowa 3 lok. 83
01-357 Warszawa | POLSKA


AUDIOREVEAL.com

MADE IN POLAND

Provided for test by NAUTILUS DYSTRYBUCJA


Review

Text: WOJCIECH PACUŁA
Images: Wojciech Pacuła | Michał Posiewka

No 207

August 1, 2021

AUDIO REVEAL is a Polish audio company specializing in the production of single-ended tube amplifiers. It was established in 2018, and its founder and designer is Mr.Michał POSIEWKA. He has been running his main business related to the electronics industry since 1989 - in the early years he dealt with the design and serial production of devices for alarm systems and access control systems. We are testing the fourth amplifier in the history of Audio Reveal, and also the smallest one - the JUNIOR.

DON'T KNOW IF YOU PAID ATTENTION, but from time to time it happens that a product is introduced to the market that was not "invented" by the manufacturer, but by distributors or stores selling devices from a given company. This applies primarily to small companies of audiophile origin, in which the boss and founder is also the designer or lead of a small group of engineers.

The classic "modus operandi" of an audio company is that after developing some type of circuit, solution, technique, or even technology, it makes one or two models that evolve over time which results in new additions to the price list, more or less expensive ones. However, some solutions are so expensive that - apart from the "in-depth" development, i.e. new versions of a given product - there is one direction: up the price list.

This was the case, for example, with the Ayon Audio Scorpio XS amplifier. Gerhard Hirt, the head of the Ayon, said back then:

To be honest, I was constantly asked by my resellers about an integrated amplifier that would cost less than 3,000 Euros. It was about something like an introduction, a gate to the tube world of Ayon Audio. The answer to these requests is the Scorpio XS, although from a business point of view it is a very difficult project for us. The buyer just gets a hell of an amplifier for the money. We are doing something like this for the first time in our history.

⸜ „High Fidelity” № 187, Nov. 1st 2019, see HERE; dostęp: 08.06.2021).

Nobody says it directly, but this is how I interpret the development of the newest Audio Reveal amplifier, named Junior. However, while going up the price list and even developing/improving existing products is well recognized in such companies and is a natural stage of development, preparing a product in a lower price range while maintaining previously developed solutions is extremely difficult. It is no coincidence that Gerhard points out that it does not make much sense from an economic point of view, and the only purpose of such a move is to attract people to the brand who would have bought products from another manufacturer otherwise.

What does this mean for us users? - This means - no less, no more but - that we get a product with an outstanding quality / price ratio, which for much less money offers us a chance to get a glimpse into what the manufacturer offers with his much more expensive devices. This was the case with the Leben CS-300 amplifier (later also in the CS-300F version), it was the case with the Scorpio XS Ayon Audio, and with the reviewed Audio Reveal Junior amplifier.

»«

| A few simple words…

MICHAŁ POSIEWKA
Owner, designer

The key features of my new amplifier are:

- output transformers by Leszek Ogonowski
- 250 W power transformer with EI 0,3 mm core, copper sheet shielding by Leszek Ogonowski,
- signal path’s capacitors - Mundorf Mcap Classic,
- Wima polypropylene capacitors,
- electrolytic capacitors: Nichicon, Epcos, Panasonic,
- resistors: Tyco Electronics, Vishay, Royal Ohm.
- ceramic fuses,
- brass RCA connectors with a tellurium copper signal pin,
- internal cabling of oxygen free copper,
- chassis made of 2mm thick sheet metal and welded in order to achieve high rigidity,
- feet made of solid aluminum,
- knobs made of stainless steel,
- front panel made of solid IROKO wood,
- an optional usage of the KT88 tubes instead of 6550,
- impedance switch,
- considerable weight of 18 kg,
- probably the smallest dual mono design on the market. MP

»«

AUDIO REVEAL JUNIOR is an integrated amplifier which features tubes as elements amplifying signal - so it is a tube amplifier, even though the power supply is a solid-state one. It features only two inputs, the output impedance (4 or 8 Ω) is changed using a switch, but there is also a remote control at user’s disposal. The device is also much smaller than the company's previous amplifiers - it measures 367 x 345 x 187 mm, compared to earlier models that measured 476 x 410 x 220 mm. Nevertheless, it looks exactly like them, except that it is sort of a miniature of them.

The chassis is made of rigid, powder-coated black metal sheets with a nice front panel made of an exotic wood. All the knobs are also made of metal and the device’s make is very nice. Inside (see design description) you will find only high quality components, such as high-power precision resistors and Nichicon, Wima and Mundorf capacitors. The device is equipped with a remote control - a very convenient to use one, as it sports only two buttons to adjust volume.

Despite the much lower price, the same technical solutions were used in Junior as in the FIRST, SECOND and SECOND SIGNATURE models. So it is a single-ended amplifier, with a single tube operating in class A in each channel - in this case it is a beam tetrode 6550 from the Russian company Tung-Sol.

The first units of the amplifier were equipped with both classic, currently produced 12AT7W tubes from Tung-Sol and selected TAD tubes, characterized by the perfect compatibility of both triodes inside (the ECC81 is a double triode). It allows user to tune the sound to his/her own requirements.

| 12AT7/ECC81 TAD Premium Selected (balanced)


TUBE AMP DOCTOR (TAD) is a reputable company specializing in tubes funded in Worms, Germany in 1993. It produces its own premium handcrafted vacuum tubes and also helps select third-party tubes from around the world that are used to build and maintain old electric guitar amps and other musical instruments.

All TAD vacuum tubes are rated, tested and approved before being matched in pairs or quartets. At the start-up stage, the tubes are burned in to form the cathode surface, balance emissions and increase the dynamics of the lintel. The company offers the following models: 6L6, EL 84, EL 34, 6550A, KT 88 and KT 66. The "Premium Selected" series undergoes additional quality tests for:

- noise,
- microphonic effect,
- gain,
- sound,
- shock,
- wiretapping,
- uniform signal strength /performance.

www.TUBEAMPDOCTOR.com

THE SINGLE-ENDED DESIGN HAS ITS ADVANTAGES, such as a short signal path, amplification of the entire signal in a single element without the need to divide the half of the sine wave into two tubes. The downside is the low output of such a circuit - Junior offers only 10 W per channel (both at 4 and 8 Ω, which is a good indication of the quality of its power supply section). However, there is nothing to be afraid of - I know from experience that high-class devices with a good power supply can drive loudspeakers better than those with high output, but with imperfect power supply.

Power supply in Junior is another element that the designer transferred from the more expensive models - we are talking about a dual mono power supply. Each channel has a separate audio circuit and its own power supply section. The advantage of a dual mono design is much higher channel separation and therefore lower inter-channel crosstalk. The downside is a higher price.

Let's look again at Mr. Posiewka's amplifier, and we will see a neat, nice device that costs relatively little, and is an equivalent of the LEBEN CS-300F (push-pull, 2 x 15 W, PLN 12 900 | JAPAN) on one side and AYON AUDIO SCORPIO XS (single-ended, 2 x 12 W PLN 13,900 AUSTRIA) on the other.

SOUND

⸤ HOW WE LISTENED The Audio Reveal Junior amplifier was tested in the HIGH FIDELITY reference system and compared to a split system consisting of the Ayon Audio Spheris III tube preamplifier (approx. PLN 150.000) and the Solution 710 transistor power amplifier (approx. PLN 160.000, no longer produced); I conducted a separate listening session comparing it with the Leben CS600X tube amplifier.

Junior stood in front of the audio rack I use, on a stand consisting of a Sonus faber speaker stand and the Acoustic Revive RST-38H anti-vibration platform. It was connected with the Ayon Audio CD-35 HF SACD player by RCA Acoustic Revive Absolute interconnects, and with the Harbeth M40.1 speakers by Western Electric NOS cables. The amplifier was powered by the Harmonix X-DC350M2R Improved-Version cable.

Recordings used for the test | a selection

COMPACT DISC
⸜ KING CRIMSON, In The Court of the Crimson King, Atlantic/WOWOW Entertainment [Japan] IEDG-01, 7” Platinum SHM-CD + DVD-Audio (1969/2016)
⸜ MICHAEL JACKSON, Thriller. 25th Anniversary Edition, Epic/Sony Music Japan EICP-963-4, CD+DVD (1982/2008)
⸜ PINK FLOYD, Wish You Were Here, EMI Records/Analogue Productions PFR25/19075810342, SACD/CD (1975/2018)
⸜ YES, 90125, ATCO/Warner Music Japan WPCR-15914, „7 Inch Mini LP”, SACD/CD (1983/2014).

LONG PLAY
⸜ CHARLIE BYRD, HERB ELLIS, BARNEY KESSEL, Great Guitars/Straight Tracks, Concord Jazz CDJ-1002, „Direct-To-Disc Recording | Limited Edition”, LP (1978)
⸜ DEAD CAN DANCE, Into The Labyrinth, 4AD/Mobile Fidelity MoFi-2-001, „Silver Line Special Limited Edition | No. 1545”, 2 x 140 g LP (1993/2010)
⸜ FRANK SINATRA, Sing And Dance With Frank Sinatra, Columbia CL 6143/IMPEX RECORDS IMP6036, 180 g LP (1950/2020)
⸜ THE BASSFACE SWING TRIO, The Bassface Swing Trio plays Gershwin, Stockfisch SFR 357.8045.1, „Direct-To-Disc”, 180 g LP + SACD/CD (2007),

»«

JUNIOR IS THE AUDIO REVEAL’S AMPLIFIER, whose sound I like the most. It is not the best amplifier from Mr. Posiewka, and his other designs are also very cool and objectively better. And yet in the sound of the "small one" there is something so uninhibitedly joyful, so melodic that we sit on the one hand focused because we want to hear everything well, on the other relaxed, because we do not have to put too much effort to put everything together - this is what an amplifier is like.

The smallest of the entire line, with the lowest maximum output, it does not show it at all. First played, the Billie Jean track from the Thriller album by MICHAEL JACKSON sounded low, confident, with great bass. The latter had a nice timbre, a clear melodic line, and although its focus was not particularly marked, it kept the rhythm very well, did not lose it, and - even less so - never got boomy.

I immediately heard something that makes the Junior's presentation velvety and smooth - withdrawing the irritating elements from the upper midrange. Jackson's album, although produced by Quincy Jones, a top producer, recorded in the best studios, has a highly compressed sound and it is hard to call it "purist" - that's how it was recorded then. With the Audio Reveal amplifier, however, it sounded in absolute internal harmony, without the nervous tension between the emphasized upper midrange and a slightly contoured bass.

As I said, Junior is an amplifier with a warm and silky sound. On the one hand, it resembles the sound of the Leben CS-300F, but it is warmer and smoother, and on the other hand, the Ayon Audio Spirit SE, but it’s more rhythmic. It's amazing how you can drive bass using such a small amplifier! Admittedly, let me repeat, it is not as well focused and as selective bass as with the larger, more powerful models of this manufacturer, but even with very low sounds on the PINK FLOYD’S Wish You Were, it was not a problem. Yes, I heard the softening and no I didn't get a selective extension in the lower region. And yet it felt like everything was in its place, as if nothing was missing.

Even more interesting is the fact that this device scales the sound well, as well as it shows the relationship in size and volume between the vocal and the instrumental backing. The previously mentioned Jackson on the radio sounds as if the vocal was the most important element and the loudest one. This is not so, it is actually a horrible compression and other tricks used by broadcasters that make us perceive it that way. The voice listened to on a good system is placed quite far in the mix, it is not loud at all - and Junior showed it nicely.

I confirmed its ability to differentiate the size of the instruments, and thus to render music realistically - considering the audio conditions - by playing an incredibly well-prepared re-edition of FRANK SINATRA's 1950 disc entitled Sing And Dance With Frank Sinatra. The vocals were quite large but not overwhelming, clear and in the foreground, yet not extinguishing the fantastic orchestra behind him. The amplifier nicely showed the difference in the way the orchestra was recorded in the large space of Columbia Records studio at 30th Avenue, and the vocal that was recorded later and has a drier timbre.

What's more, the tested amplifier is so resolving that I had no doubts that the track All Depends on You, the only one in this set still recorded on a 16” transcription disc, sounded warmer, and although the brass were not as natural as in the tracks recorded on the tape (Ampex 200A), the vocal was better, fuller, more saturated here.

Moreover, the Junior is not the most selective amplifier for the money I know. In this respect, both the aforementioned Leben and the Austrian Ayon Audio are doing better. What's more, a transistor amplifier for up to 10,000 zlotys will sound more accurately, show the edges more clearly, and details on the stage more precisely. The Junior treats them as a whole, differentiated but still a whole. It prefers big planes, which was great with the direct-to-disc disc THE BASSFACE SWING TRIO, The Bassface Swing Trio plays Gershwin. It has a very direct presentation, which was polished, warmed and shown very nicely by the Polish amplifier, but similar to the Sinatra’s album, or the DEAD CAN DANCE’s Into The Labyrinth, played immediately afterwards, in the Mobile Fidelity version.

⸜ TUNG-SOL vs TAD TAD tubes bring the sound closer to the listening position. Still Jackson's vocals were in good proportion to the rest of the instruments, but now it was clearly closer to me. While the Tung-Sol tubes withdrew part of the upper midrange and treble, the TAD tubes opened the midrange. It was not as silky as with Russian tubes, but it had more energy, previously softened and evened.

On the other hand, the bass with these tubes was not so even, so clear and so well controlled. The midrange of the TADs was nicer, more saturated and more selective. In turn, its bass was not as interesting and as good as with the Tung-Sol. So it's great that you can have both these sets of tubes, because the amplifier behaves differently with them - so different that it becomes a slightly different device. Which in turn shows how transparent the amplifier is and how well the output stage works - 6550 tubes and output transformers.

SUMMARY

JUNIOR SLIGHTLY WARMS UP THE SOUND. So, as always, we pay a tax on pleasure - and the Audio Reveal sounds incredibly pleasant. It does not matter whether I listened to a fancy LP remaster or an excellent production, but still "production" from CDs, it was always nice, pleasant, relaxing. Its bass is surprisingly strong and keeps the rhythm perfectly, even with loudspeakers as difficult to drive as the Harbeth M40.1. The low tones have rounded edges and are not particularly clear, yet they build a very good basis for the whole presentation.

The Polish amplifier sounds great and is suitable for long listening sessions during which we will not fall asleep from boredom - it offers an exciting sound - and we will not get anxious - its sound is relaxing at the same time. There is something real in its presentation, that we will not get for the money from solid state amplifiers, but also something credible, which makes us want to listen to it. Bravo!

DESIGN

JUNIOR IS, SO FAR, THE SMALLEST amplifier from AUDIO REVEAL. Its dimensions - 367 x 345 x 187 mm (W x H x D) make it similar to the Leben CS-300F and Ayon Audio Spirit SE amplifiers. It is still Mr. Posiewka's amplifier, there is no doubt about it, both in terms of technical solutions and appearance.

Junior is an integrated tube amplifier with a semiconductor power supply. There are two tubes in each channel - a low power dual triode 12AT7 in the input stage and a 6550 beam tetrode in the output; the output tubes work in single-ended mode. In this case, we have a choice of two types of input tubes - the base, that is 12AT7W, produced by the Russian company Tung-Sol, and "premium" ones come from TAD. The output tubes come from Tung-Sol.

The appearance of the amplifier is typical for this class of devices, that is the front panel is low and the tubes are exposed. Behind them there are transformers - power supply and output ones - closed in shielding cups. The front is made of exotic wood with metal inserts. There are three knobs here - the power switch, volume control and input selector, also made of metal. On the side there is a red diode, blinking when the amplifier is starting.

The Junior is a dual-mono amplifier with separate power supplies for the left and right channels. The whole is assembled on one large printed circuit board with a few auxiliary ones. The signal is fed to solid, screwed, gold-plated RCA sockets - we switch between the active input with relays (Relpol). After selecting with long shielded interconnects (OFC) we go to the front, to an Alps potentiometer driven by a motor. After attenuating the signal with short cables, we go straight to the input tubes.

The power supply uses Nichicon and Epsos capacitors, and the circuit uses Nichicon Muse series capacitors and Wima polypropylene capacitors; Mundorf MKP M-Cap capacitors deal with the coupling of the stages.

The Audio Reveal Junior is a very nice, cleanly built device, and uses high-class components.

Technical specifications (according to the manufacturer)

Signal tubes:
2 x 12AT7 (ECC81)
Output tubes: 2 x 6550
Frequency range: 20 Hz – 28 kHz (±0.5 dB/1 W)
Nominal output (1kHz):
10 W RMS/8, 4 Ω
Inputs: 2 x RCA
Input impedance: 50 kΩ
Start time: 60 s
Nominal power consumption: 130 W
Dimensions (W x G x D): 367 x 345 x 187 mm

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Reference system 2021



1) Loudspeakers: HARBETH M40.1 |REVIEW|
2) Line preamplifier: AYON AUDIO Spheris III Linestage |REVIEW|
3) Super Audio CD Player: AYON AUDIO CD-35 HF Edition No. 01/50 |REVIEW|
4) Stands (loudspeakers): ACOUSTIC REVIVE (custom) |ABOUT|
5) Power amplifier: SOULUTION 710
6) Loudspeaker filter: SPEC REAL-SOUND PROCESSOR RSP-AZ9EX (prototype) |REVIEW|
7) Hi-Fi rack: FINITE ELEMENTE Pagode Edition |ABOUT|

Cables

Analog interconnect SACD Player - Line preamplifier: SILTECH Triple Crown (1 m) |ABOUT|
Analog interconnect Line preamplifier - Power amplifier: ACOUSTIC REVIVE RCA-1.0 Absolute-FM (1 m) |REVIEW|
Speaker cable: SILTECH Triple Crown (2.5 m) |ABOUT|

AC Power

Power cable | Mains Power Distribution Block - SACD Player: SILTECH Triple Crown
Power (2 m) |ARTICLE|
Power cable | Mains Power Distribution Block - Line preamplifier - ACOUSTIC REVIVE
Power Reference Triple-C (2 m) |REVIEW|
Power cable | Mains Power Distribution Block - Power amplifier - ACROLINK Mexcel 7N-PC9500 |ARTICLE|
Power cable | Power Receptacle - Mains Power Distribution Block: ACROLINK Mexcel 7N-PC9500 (2 m) |ARTICLE|
Power Receptacle: Acoustic Revive RTP-4eu ULTIMATE |REVIEW|
Anti-vibration platform under Acoustic Revive RTP-4eu ULTIMATE: Asura QUALITY RECOVERY SYSTEM Level 1 |REVIEW|
Power Supply Conditioner: Acoustic Revive RPC-1 |REVIEW|
Power Supply Conditioner: Acoustic Revive RAS-14 Triple-C |REVIEW|
Passive filter EMI/RFI: VERICTUM Block |REVIEW|

Anti-vibration

Speaker stands: ACOUSTIC REVIVE (custom)
Hi-Fi rack: FINITE ELEMENTE Pagode Edition |ABOUT|
Anti-vibration platforms: ACOUSTIC REVIVE RAF-48H |ARTICLE|

Isolators:
  • PRO AUDIO BONO Ceramic 7SN |REVIEW|
  • FRANC AUDIO ACCESSORIES Ceramic Classic
  • HARMONIX TU-666M "BeauTone" MILLION MAESTRO 20th Anniversary Edition |REVIEW|

Analogue

Phono preamplifier: Phono cartridges: Tonearm (12"): Reed 3P |REVIEW|

Clamp: PATHE WINGS Titanium PW-Ti 770 | Limited Edition

Record mats:
  • HARMONIX TU-800EX
  • PATHE WINGS

Headphones

Headphone amplifier: AYON AUDIO HA-3 |REVIEW|

Headphones: Headphone Cables: Forza AudioWorks NOIR HYBRID HPC