Allnic Audio A-2000 25th Anniversary Power Amplifier
This is the 25th Anniversary edition of Allnic Audio’s A-2000 stereo power amplifier. The 25th is both a 100 watt (pentode) and 50 watt (triode) push-pull design that retails for $9,900. The pentode/triode feature is switchable ‘on-the-fly’.
Changes from the original A-2000 include upgraded output transformers, a modified chassis with a newer, swept look and a power tube swap from KT88s to KT150s. Designer Kang Su Park also made some circuitry changes for greater stability and tube longevity.
The 25th is a spectacular looking piece of advanced audiophile art. It’s certainly my favourite looking piece Allnic Audio has sent for review. The amplifier comes in black or silver and has a shipping weight of almost 40kg.
My Use
Unpacking and setting up the amplifier is a two person, lift-at-the-knees, job. Do not try this alone! Between my superhuman wife and my sorry self, we wrestled it from its careful packaging to the top of my Target rack. The KT150 tubes and their chimneys are tall and need lots of room for airflow. Locate it on top of your rack or on a dedicated amp stand.
David Beetles, Canadian distributor, who kindly arranged the review unit be shipped from Korea, suggested a week’s worth of listening before evaluation. I was also careful to heed his directions about breaking in the tubes, their initial cycle, etc. And the specific direction to always power on/down in pentode mode.
Beetles hinted break in may be a bit of a chore. Allnic suggests 100 hours initially, then a further 100 refining the sound. The 25th uses very large output transformers (114 mm) with nickel cores. These massive cores need time to bed in.
To be sure, you’ll be getting good performance and power from Mile 1, but the refinement this excellent design is capable of will take some time to uncover. I heard quite a difference after about fifty hours, the time I could allot to break in. And with a further fifty hours of listening, the amplifier was telling much of its story. I would suggest to those auditioning, ensure the amp has the appropriate number of hours to hear at its very best.
That said, the quality of manufacture, with NOS tube compliment, its splendid sound with pentode/triode switching on the fly for $9,900 is relatively inexpensive in our avocation.
Associating components with the 25th was an Allnic affair with the exception of the Bergmann Magne Turntable and my Alta Audio FRM-2M Loudspeakers. As such, I toggled to 4 Ohms on the 25th’s outputs to accommodate the Altas. The A-2000 loved the familiarity of the ancillaries. Cables, pre and phono, were all top of the line Allnic. Connectors are very high quality and general fit and finish is superb.
The unit’s beautiful tube metres suggested that all were functioning and biased normally. Nothing went bump in the night during transit.
Note the small yellow bias screws above and below the metre. They are very sensitive to changes. Need to bias? Follow the very detailed but clear instructions in the manual.
Features
The amplifier uses the following tubes: KT150 x 4 (power triode), E282F x 4 (second stage drivers), 5654 x 2 (first gain stage).
As with all Allnic tube gear we’ve reviewed, the 25th features soft start circuitry. And along with 100 watts of pentode power, the Allnic promos suggest a ‘SET like’ 50 watts in triode. Power tubes have individual fuse protection. And if you need 16 Ohm speaker terminals, you can special order from the factory.
Specifications
Output Power: 100w (8Ω load, at 1KHz)
Distortion: 0.17% at 1KHz at 10w
Frequency Response: 20Hz-20KHz Flat
S/N Ratio: -80dB (CCIR, 1KHz)
Damping Factor: 8at 8Ω load at 1KHz
Voltage gain: +26dB
Input Impedance: 100KΩ (single-ended, unbalanced)
Input Sensitivity: 1.3V for rated power
Dimensions: (WxDxH) 430mm x 430mm x 240mm
Sound
The A-2000 25th Anniversary Power Amplifier in both pentode and triode modes had power aplenty to drive my 87.5 dB Altas to ear busting levels in my small listening room. Knowing all too well Kang Su Park’s design philosophy, I have no doubt this incredibly well built and good looking amplifier will drive most fairly efficient loudspeakers to plentiful levels in small to medium size rooms. So, most residential applications will be covered. You won’t be using a device such as this for your frat house party.
In either mode, the amplifier was dead quiet—no hissing, no tube rush. Distortion was never heard, even when cranked in 50 watt triode mode.
The switching between pentode and triode on the fly is very cool and a reviewer’s dream. Aural memory can be woefully short. The front button allowed me to nail down the differences and which mode I preferred in my system.
Pentode: With a full 100 watts available, it was obvious that full bodied dynamics had an extra slam and weight that, at times, could elude the triode setting. Yet, the transparency and delicacy one listens for from SETs and well designed push pulls was there in pentode for all genres of music. Whether gentle bow strokes deep in the mix during a Mozart string quartet slow movement or thunderous bass on Reference Recordings’ Arnold Overtures, the amplifier was up to the task. If you want a pentode circuit with both delicacy and power, the 25th’s your guy.
Triode: I’m a big fan of SETs. With the right speakers and a great vinyl setup, there’s nothing I enjoy more in high end audio. The sweetness, the light, the layering of subtleties, the inner workings of musicians’ minds laid bare. All are heard under a quality SET setup. I found that less so under the push pull variety. So, although the folks at Allnic quite rightly suggest ‘SET like’ sound for its triode mode, it was more of an aspiration than a full SET experience. Beetles suggestion regarding the 200 hours break in may well add some delicacy to the triode sound. I wish I had the unit longer.
The triode sound was a little more diaphanous than pentode, but my feeling was the energy was robbed somewhat on demanding orchestral music. For smaller scale repertoire, the triode setting shone. As an example, the beautifully recorded Bach Concertos for Organ and Strings played with exquisite style by Les Muffatti with Bart Jacobs (Ramée), was incredibly delicate when the organ was played in its top rank, flute stop. The bell-like quality organ fans love to hear was better replicated by the 25th’s triode mode. As such, a careful choice of circuit when playing specific repertoire will be of added benefit. And what I assume Kang Su Park intended when he designed the amplifier. So, whatever your pleasure, the 25th can deliver the tube sound your require.
Summary
I’m hoping to get another chance to hear the splendid A-2000 25th Anniversary Power Amplifier for a longer review period as a follow up. I think it has greater secrets to tell me, especially in triode mode, where I think another 50 hours on the chassis would bring it closer to the ‘SET-like’ description from the manufacturer. But after 100 hours in its company, I was very much enjoying its look and versatility with all sorts of genres and repertoire. If you are ready to upgrade your amplifier to the $9,900 asking price, you listen to all types of music and love the sound tubes make, then the 25th should be on your short list for further enquiry. Highly recommended.
Further information: Allnic Audio
