AGD Productions Andante Streamer/preamplifier and The Audion mono power amplifiers

If ever the phrase ‘looks can be deceptive’ holds true, it’s regarding this duet of devices from the relatively little-known Californian audio brand AGD Productions. At first glance, you could easily be forgiven for thinking this is a valve pre-power combination, possibly a low-power single-ended triode mono amp, or at most a hybrid. The orange-glowing glass bottle in the centre of each power amp is a bit of a giveaway. In fact, the Adante and The Audion are almost exactly none of these things.

Let’s start with the Andante. It’s a highly configurable, UPnP streaming preamplifier that can turn its hand to a surprisingly wide range of PCM and DSD-shaped digital sound files, and all the main flavours of file format, as well as line level sources and can even run a natty line in software-driven MM/MC phono stage. It’s controlled from a simple Apple remote and has the sort of display that you can see across a room… the size of Lichtenstein. This can be set very dim, however, and that can make basic operation a little bit “is it on?” not helped by a slightly slow response time to Apple remote commands. Two rows of multi-function click-stop push buttons can drive all the functions of the Andante, but the Apple remote makes like a lot easier.

I’m always a little concerned about streaming solutions made by smaller companies. While streaming is no longer a hole in the company budget that can only be filled with engineers, getting a robust and easy to use streaming platform is usually beyond most small-to-medium brands. It seems, from the outside at least, that unless you devote a significant percentage of the company’s total R&D budget on streaming, you can either have something that looks nice, or something that works. AGD has gone more for the latter option, relying on third-party command & control. The Andante’s functionality is driven by Bubble UPnP if you are planning some local music serving, but it also supports Tidal, Deezer and Qobuz for online streaming and AirPlay for general music management. Note that none of these options are a UPnP/DLNA music server platform, and home networked audio systems will need to make provision for that (in my system, I tried both Melco and Naim solutions successfully).

Meanwhile, The Audion is a small monoblock amp (two of them fit atop the Andante, which is itself significantly narrower than the standard 19”/48cm amplifier size. This is the smallest of three mono amps in the range. The key innovation here is what AGD calls ‘GaNTube Technology’. This is a PWM switching amplifier using very high-speed Gallium Nitride (GaN) power MOSFETs housed inside a KT88 sized glass tube. It even uses a KT88 tube base, although swapping the GaNTube out for a real KT88 isn’t a good idea! This all means that the deceptively small amplifier can pump out a meaty 85W into eight ohms which doubles to 170W into four. It can also be driven in balanced and single-ended mode (we used balanced).

GaN transistors are not a cheap option, nor are they especially easy to implement in an audio context, but they have the sort of slew rate that most amplifiers can only aspire to. They also deliver close to textbook resistance to parasitic effects of altered resistance, capacitance and inductance even at comparatively high power across the audio frequency range, meaning the AGD’s MOSFETs of choice are inherently lower noise and higher power designs than their more commonplace silicon oxynitride brethren.

I spoke to a couple of people who simply didn’t ‘get’ the idea of The Audion at all. They couldn’t parse the idea of something that looks like a valve amp but is in fact a variation on a PWM design (albeit a unique and clever variation), and ultimately one got almost irate at the idea, thinking it a ‘trick’, comparing it to a photograph of a landscape compared to the landscape itself. I have a very different take, from a purely aesthetic position; people still buy tube/valve amps, and some do so primarily for the looks. Many of those might not actually need, want, or have the kind of loudspeakers that benefit from using a tube/valve amp. The AGD amps offer an aesthetic option that uniquely address that demand. Oh, and when it comes to that ‘photograph of a landscape’ argument, I give you… Ansel Adams!

Each one comes in its own flight case, a Peli design you could use as hand-luggage if you removed all the foamy bits. This gives an idea of just how small and light the Andante/The Audion combination really is. Those of us used to trying to lift amplifiers the size and weight of a car engine onto a stand will come to view the likes of AGD as a breath of fresh air. However, while AGD shows images of the amps stacked on top of one another, I think that goes a little far. While in use I heard no negatives in stacking amps this way, audio-compulsive disorder suggests using at least two and possibly three shelves for the combination. Functionally speaking, though, they are easy to use, and those amps require no warm-up at all.

This combination is every inch the audiophile’s dream. It’s incredibly detailed and gives an extremely precise soundstage with all that inner microdynamic detail and presence that makes well-recorded acoustic instruments in a live environment come to life. ‘Amelia’ from Herbie Hancock’s interpretations of Joni Mitchell songs [River: the Joni letters, Verve] was almost made for the AGD’s presentation. It’s a lithe, relaxed-yet-focused sound (this reads like a paradox, but once you hear that combination in action, you realise that it’s something that’s both present in the live space and all too often missing from audio reproduction). Instruments are both individuated and have their own sense of physical space within the solid and three-dimensional soundstage, and yet cohere extremely well with one another, and there’s always a sense of both a band and bandleader. This is difficult to portray with this recording, as in many supposed audiophile systems, it often ends in musical disarray… as if the band is under-rehearsed or the bandleader is ‘phoning it in’. Here, everyone hangs tight!

The amplifiers are also outstanding at taking control of a loudspeaker, controlling the drive units in an authoritative, but not authoritarian, manner. This means bass won’t boom unless boom is called for, and the midrange and treble drive units are tasked with getting on with the job less impeded by the actions of other drive units. Put simply, the AGD makes your loudspeakers sound better than they had any expectation of sounding, because the amplifier is doing its job so well.

The AGD combo is also fast. While I think they should be considered as a whole; I lay this speed primarily at the mono amps. These amps react to transient information with a speed that borders on the psychic, and couple them with some already transient-friendly cable (like Nordost Odin, for example) and the speed of delivery is very much that of an audio system getting completely out of the way of the music it plays. Playing ‘The Limit’ by Darkside [Spiral, Matador] and that idiosyncratic electronica (combining trip hop, EDM and a very fast and almost click-track beat) is played with the sort of pace that is usually the stuff of smaller, responsive single-ended triode designs.

I’m not sure whether this is a downside in wider terms, but the one thing the AGD combination doesn’t do well is ‘suffer fools gladly’. If you play some musically-compressed, thin sounding pop music, it presents it as such, warts ‘n’ all. As such, this is not the family party amp, because a night of Europop bangers or hip hop might leave you cold. That said, Billie Eilish’s Happier Than Ever album [Interscope] sounds pretty good through the AGD combo…

I’ve tried to rid myself of the ‘anti-switching’ bias some reviewers have toward PWM amplification, primarily because things have moved on a lot since they first appeared toward the end of the 20th Century. Nevertheless, some myths are persistent, especially when they come with a kernel of truth to them. One of my last negatives toward PWM-powered designs was the ‘they don’t drive difficult loads’ and that evaporated in listening to the AGD with the deceptively difficult upper bass impedance of the Wilson Duette Series 2 loudspeaker. The amps aced this low impedance point even at relatively ‘beefy’ levels and playing some balls-out AC/DC. OK, so some 1980s era brick wall masquerading as a loudspeaker with an impedance plot that burns out most amps will probably see the AGD hitting its end stops, but in truth, that ability is a bit of a revelation.

For a comparatively little-known company, AGD is hitting them out of the park here. The Andante is a fine preamplifier with a ‘first, do no harm’ streamer on board, and The Audions are some of the fastest, most expressive amps you’ll hear this side of the audio’s super league. This is an important new design and well worth checking out!

TECHNICAL SPECIFICATIONS

Andante streaming preamplifier

• Analogue Inputs: 2 Single ended (RCA2, RCA3), 1 XLR inputs (XLR)
• Phono input: Moving Magnet and Moving Coil selectable via Menu
  MM Input Impedance: 47kΩ, S/N ≤ -80db; MC Input Impedance: 420Ω, S/N ≤-70db; RIAA Accuracy: < 0.5dB
• Digital Inputs: 1 USB, 1 × AES/EBU (XLR), 1 Coax, 1 × TOSLINK (max sample rate 192 kHz) LAN (Ethernet Port), Bluetooth AptX
• Analogue outputs: 1 XLR, 2 RCA
• File formats supported: MP3, WMA, MPEG-4 AAC, WAV, FLAC, AIFF, ALAC, DSD
• Digital precision: PCM to 768kHz, 32-bit. DSD to 22.5792MHz and 24.576MHz (DSD512); Streaming Services: DNLA, UPnP, ROON, AirPlay (via LAN)
• Frequency Response: 1Hz–100kHz ± 0.2db
• THD+N (Balanced): ≤ 0.005% THD+N (Single Ended): ≤ 0.009% S/R: ≥110db
• Dimensions (W×H×D): 28 × 9 × 280cm
• Weight: 13kg
• Price: From £11,695

The Audion power amp

• Nominal Output Power at 0.1%: 85W (8Ω), 170W (4Ω)
• THD+N 10W/1KHz: < 0.005%
• Frequency Response: 5Hz–100kHz (±3dB)
  Dynamic Range: >120dB
• Dimensions (W×H×D): 19 × 14 × 19cm
• Weight: 3.1kg
• Price: From £7,895 per pair

Manufacturer: AGD

URL: agdproduction.com

UK distributor: Whole Note Distribution

URL: wholenotedistribution.co.uk

Tel: +44(0)203 9115 549

Sole UK retailer: Val Hifi

URL: valhifi.co.uk

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