The Allnic Audio A-2000 25th Anniversary SE amplifier is a limited production 100-watt (pentode) push-pull, stereo power amplifier. Does it sound as good as it looks at the price??
Throughout the years I have been involved in this ingratiating hobby, I have always had a love-hate relationship with tube (valve) amplifiers. Not necessarily because of the distinctive sound differences they purvey, vis-à-vis solid state, but mainly because of the timely long-term upkeep and cost-effectivity of tube amplifiers.
My first tube amplifier was made by Antony Michealson back in the early 1980s. This British amp sounded quite good but was highly unreliable. Of course, this can also pertain to the quality of workmanship of any high-end audiophile product, without a doubt.
The Allnic 100-watt push-pull pentode power amplifier is celebrating its 25th anniversary SE model with some confidential changes having been made from the original A-2000. Upgrades made in the 2000 ‘SE’ model include improved, more attractive swept-style chassis modifications, better output transformers, and a switch from KT88 to KT150 power tubes. Moreover, the designer has altered certain circuitry for improved stability and tube longevity, the latter of which is of unbridled importance to me.
The Allnic 25th SE uses four KT150 power triode tubes, four 6S4 second-stage drivers, and two 5654s within this heavy, powerful, and well-built amplifier’s first gain stage. The updated model also includes another special feature that is very impressive and quite durable for the enthusiast audiophile:
*An Analogue Power Tube Current Monitor” — The A-2000 25th SE contains a separate analog current meter for each pair of power tubes to offer constant current (bias) monitoring for the power tubes. By using the bias control knob for the appropriate tube, the meters make it incredibly simple to assess the state of each tube at any time and to react promptly to any variation in bias. When compared to traditional LED bias monitors, the meters provide a straightforward, unambiguous indicator of each tube’s status. Quite impressive, to say the least.
Adding to this, the 25th Anniversary SE is endowed with soft start circuitry and along with 100 watts of pentode power, the Allnic offers an ‘SET 50 watts of power in triode mode which can be switched on or off as the amplifier works. The power tubes used here confidently boast individual fuse protection. It was a pleasure to be able to take advantage of this “switching” from pentode (100 watts) to triode mode while playing music with a button on the front panel. Later in the review, I will describe the audible differences observed.
A bit surprisingly, this tube amplifier was completely silent in both modes—there was no tube rush or hiss. Even in the 50-watt triode mode, no distortion was in any way audible!! In the 100-watt pentode mode, full 75Db sound levels (and higher peaks) were measured without a trace of background noise. This amplifier was surely built to the highest standards.
BREAK IN
Breaking in this amplifier was not as long as I had expected to appreciate its fully operating sound proficiencies. Distributor in the States, John Ketcham of Kevalin Audio told me to just plug it in and let it rip! Allnic does, however, suggest 100 hours initially, for refining the sound. The 25th Anniversary uses very large output transformers (114 mm) with nickel cores. These massive cores need some to dig in and start blooming
Without a doubt, you’ll receive good performance and power right away, but it will take some time to realize the full potential of this wonderful design in terms of refinement. After listening for around 10 hours, I noticed a small improvement in sound quality, and after 15 hours, the amplifier was developing very beautifully. To those who are auditioning, I would advise making sure the amp has the necessary number of hours to hear it at its finest.
SOUND-PENTODE/TRIODE MODE
The pentode mode offered a full 100-watt output from the glowing tubes of the Allnic and it was quite obvious that this mode showed off some awesome tube “dynamics” while maintaining a glorious bit of romantic and harmonic richness. The sound was lush, smooth, deep, and perpetually airy and I was starting to think to myself, man, what have I been missing with tube amps lately?
A classically well-designed tube amplifier has a pleasantly full, warm sound that is mostly due to the ability of tubes to generate rich, even harmonics. Higher harmonics, particularly odd harmonics, will be produced when the signal passes across nonlinear components. Abnormal harmonics are a major factor in the deterioration of sound quality.
Contrastingly, the nonlinearity of the electron tube is much smaller than that of the transistor and is one of the reasons that a good tube amplifier can sound somewhat more pleasing than some solid-state amplifiers. Undoubtedly, the loudspeaker it is matched to can also make an immense difference in what we are hearing.
As the Allnic amp continued to break in, I found myself switching back and forth from the pentode to triode mode (50 watts) and noticed some subtle but obvious differences. First off, the triode mode seemed to sound much better with small ensembles and singers with acoustically backed-up musicians. This was a delicious sound within itself, and there were more slight audible differences that were eventually observed between the two formats.
No doubt, the audible expansiveness in the pentode mode was more soundstage “filling” than in the triode mode. Orchestras seemed to gain some robust width and space between instruments on the soundstage as well. With large pop groups, the sound had a slightly better dynamic range when listening closely.
Furthermore, even though small string quartets and one or two-person acoustic and vocal offerings were very intimate sounding in triode, the switch to pentode sort of brought the sound a touch more “out into the open” with better width and depth as well as hall ambiance. Let’s just say that as I kept inching back to the Pentode mode, I realized that this was offering me a more robust, dynamically altruistic tone and sound that I preferred in almost all the listening tests with different program sources from pop, and rock to classical.
When all things settled in, although the triode sound was a little more ethereal than pentode, I thought the vigor was somewhat sapped when playing hard orchestral music. One good example of this would be our recently reviewed recording of Leon Fleischer and George Szells remaster of the Beethovens 4th piano concerto and Mozarts 25th, on Sony.
In pentode mode, the orchestra seemed a spec wider and more evenly balanced in the soundstage while piano tones were seemingly more natural to my ears. It appears that in triode, the balance shrinks minutely while the piano becomes a touch more forward. Yes, the triode is a bit more “cozy” sounding but ultimately not as well presented audibly to my sensitivities.
As a result, when playing a particular recording, careful circuit selection will be advantageous, which is what I suppose the designer of this amplifier had in mind. Hence, the 25th SE can give the tube sound you desire, in whatever your mode of preference.
Another interestingly perceived observation with the Allnic was that some of my reference loudspeakers were sounding a bit more realistic tonally and dimensionally with the amplifier’s accurately lush midrange most specifically. Add to this — believe it or not, some awe-inspiring deep bass performance as well. Depending of course on the loudspeaker in use, the Allnic 25th Anniversary was a huge surprise in displaying large bass drum “thwacks” and quite easily divulged some outstanding results with the speakers I auditioned them with. (see below) The effect here was guiding me towards some new perspectives on what a well-designed tube amplifier can audibly reveal.
Stereo imaging, scale, and soundstage width were first-rate, as should be expected for this standard of design quality. The treble range left almost nothing to be desired and perhaps…..was a touch “silkier” sounding on some sources than with a few of my reference solid-state amplifiers. Overall then, it is truly hard to fault the 25th Anniversary SE amplifier on almost any level of its production, build, and overall sound quality. That’s a mean feat in itself, particularly at the 25TH SE’s relatively modest new asking price of $7,950!
CONCLUSION
Having just got back into listening to a few tube amplifiers at hand, I can say that “absence makes the heart grow fonder”. The Allnic Audio 25th Anniversary SE tube amplifier is a limited and candidly excellent product. I have not spent this much time in a long while enjoying the sonic effects of a great tube amplifier since the Allnic came to my listening room.
The amp sounds ‘up to the mark’ with virtually all types of music. It is full-bodied and transparent displaying a sincere, lovely, and lustrous presentation in both its triode mode (50 watts) and particularly, the pentode 100-watt mode. With great dynamics, yet subtle midrange and bass accuracy, I can argue that it will match up with and handle almost any loudspeaker load it is used with.
Not to worry, the Allnic pentode mode has plenty of power on hand to get truly high listening levels without distortion of any kind. This amplifier may even take a particular loudspeaker of your favor to a differet level of refinement, without a doubt! At a limited production price now of $7950, one can surely and finally have their cake and eat it too!
Allnic A-2000 25th Anniversary SE amplifier ~ $7,950
The Review system: Loudspeakers: QLN ONE Loudspeakers~ Harbeth Compact 7ES-3 XD loudspeaker ~ Quad ESL-63, Q Acoustics Concept 500 ~ Digital: Mojo Audio ‘Mystique’ X DAC ~ Innuos Zenith Mk.3 server/streamer ~ Audio Note (UK) CD3.1x/2 player/DAC Analog: Audio Technica LP-7/ZYX Bloom 3 mc cartridge Amplification: ~Pass Labs XP-12 preamp, Pass Labs XA30.8 power amp ~PS Audio M1200 ~ Cables/ Conditioners: Argent/Pur Silver stranded loudspeaker cables, Audience Studio One loudspeaker cables / Inakustik AC-3500p power station &, AC-2404 reference Air Power Cord ~ Audience Studio 1 interconnects,~ Clarus “Crimson” 75-ohm digital spdif / Audio Art 1 e” AC Power Cord
CONTACT:John Ketcham info@kevalinaudio.com
7275 NE Avalon Drive Corvallis, Oregon, 97330, U.S.A
503–292–5592
WHERE the MUSIC BEAT meets the AUDIOPHILE ELITE !
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