Trilogy 914 preamp and 994 mono power amplifiers

REVIEW
Alan Sircom
May 12, 2025

Trilogy has a small but growing range of amplifier products. Two integrated amplifiers, three line-only preamplifiers, a stereo and two mono power amplifiers, two headphone amplifiers (one dedicated for use with electrostatic designs) and a phono stage. The 914 preamplifier and 994 mono power amplifiers are the latest in a long line of understated amplifier excellence.

The founder and designer Nic Poulson made his audio bones in the BBC’s broadcast engineering department. The excellence-driven goals of the BBC of the 1980s never left him. They have been at the core of Trilogy since the brand started in 1990.

Drive to excellence

This drive to excellence is why Trilogy amplifiers are not bristling with streamers or on-board DACs. That’s not a fear of digital; Nic’s amps have extremely sophisticated digital control options. It’s that convenience often comes at a cost. Placing a DAC, a streamer, a phono stage and a line preamplifier in one box costs sound quality. And, for Nic, that’s too high a price to pay. Even though we are in a convenience-led world, and many want the same name on everything, that resolute ‘do what you know best’ approach is worth its weight in gold.

The 914 preamplifier is a fully balanced, zero-feedback design. It has three balanced and three single-ended inputs and one balanced and single-ended output. Switching between inputs is performed by relay, so you get a little ‘click-clack’ rather than a selector switch (the sort of ‘belt and braces’ approach the BBC instilled in Nic; relays won’t wear out after a decade or so).

In a way, this is a trickle-down version of Trilogy’s 915R flagship preamplifier. You might also consider the 914 as a logic-controlled set of power supplies designed to drive 6H6P high-transconductance tubes. Inside the chassis, there are three transformers (one for valve heaters, one for high-tension supplies, and one for ancillary control electronics), along with four shunt-regulated power supplies.

The amp is passcode protected, and the logic circuit allows many adjustments, including labelling devices, gain trimming, display brightness, sleep countdown, timed switch on, and more. The rotary switch and buttons on the front panel control all of this. There’s also a spiffy metal remote.

Mini-Me

If the 914 is a ‘Mini-Me’ of the 915R, then the 994 monos are a slimmer version of the larger 995R monos. Not really ‘slimmed down’ in that it can run at 140W in Class AB into an eight-ohm loudspeaker load. However, physically it’s a slimline design, with each one about the size of a large toaster. In an audio industry that seems to judge performance by physical size and weight, you need to set those preconceptions aside with the Trilogy 991 and 994 mono amps. These are big hitters, just not in a big box.

Like the bigger 995R, the zero feedback 994 can operate in Class A, providing a 20W output. There’s also a ‘tweener’ ecoA mode that behaves like Class A during music playback but reduces the bias when there’s no signal. I’m sure there’s a difference between Class A and ecoA, but it’s sonically minor. The LED on the panel displays status, and you can toggle between the classes by pressing buttons. Trilogy enhances heat dissipation by making the heatsink a feature of the front panel, and I think it looks pretty good. Once again, this hybrid amplifier uses the 6H6P ‘supertube’ in a grounded grid configuration to drive the compound output stage.

Chocolate

There’s something infinitely captivating and enjoyable about the sound of Trilogy’s 914 and 994, especially when used together. Curiously, they both deliver a similarly refined, rich, deep and warm tone that one might expect to yield something excessively soft and lush. Instead, the combination produces an engaging and musically adept sound— a kind of dark, chocolatey richness.

Sounds are beautifully placed within a deep, naturally layered soundstage. It doesn’t matter whether that soundstage is a small jazz club or a large orchestral space; the size and scale of that space are very accurate, and there in the room with you. Each sound on that stage has its own shape and tonality. This may seem like no big deal, but the more you listen to the Trilogy combination, the more you appreciate it.

The amplifiers deliver the sort of deft, harmonically well-structured, textured sound you expect from the absolute pinnacle products. I overuse the Joyce DiDonato album Stella Di Napoli [Erato] but for a reason; it highlights everything mentioned above. It’s a layered, spatially precise piece of music and – while it never sounds bad – it can be thrown off by DiDonato’s powerful mezzo-soprano obscuring the subtlety and elegance of the other musicians. Here, the interplay is rendered beautifully and perfectly; ‘beautiful’ is entirely apt here as it’s a sound of such grace and scale you find yourself drawn into the elegance of the music itself.

Well-balanced

It’s a remarkably well-balanced sound, with no accent on any part of the sonic signature and just a hint of richness. That means that when you get out of Bel canto mode and want to play something with a bit of a beat, the Trilogy 914 and 994 rises (or, in the case of playing ‘Baddadan’ by Chase & Status [2 RUFF, Vol.1, EMI] sinks) to the occasion perfectly. I quickly stopped taking notes and started taking in music. There’s a good, weighty bass to the sound when called for, that gives anything from big band to choral music a sense of weight and rootedness that’s extremely attractive.

However, it’s only when called upon; there’s no point giving ‘Laura’ by Natasha Khan/Bat For Lashes [The Haunted Man, Parlophone] too much bass, at least until the strings kick in. And that’s exactly what the Trilogy duo do so well; her voice and piano playing are exceptionally well rendered, but when the strings join in, they come as a surprise. Normally it’s just ‘oh, they threw in a string section’, but the freedom of dynamic expression coupled with the open and spatial qualities of the amps make that happen beautifully.

Class A or AB

These conclusions were drawn up in Class A mode, played through my regular loudspeakers. Switching to Class AB traded some of the effortlessness for slightly more dynamism and some added heft to the bass. However, it wasn’t that the Class A operation had less slam and impact or that the Class AB version lacked fluidity. It was simply that there was slight perceptual shift in performance between the modes.

In truth, most people need never move out of Class A (or ecoA) unless they are into playing Mogwai albums at concert levels in the home. All of which makes you wonder; if the Trilogy 914 and 994 combination is this good, what do you get when you go up to Trilogy’s 915R preamp and 995R amps apart from balanced input in the power amp?

Consistent similarity

While comparisons are odious, there’s a consistent similarity in sound that I feel needs to be addressed here. There is a striking similarity in performance between the 994 and the Robert Koda Takumi K-160. Both amps possess excellent transparency, good imaging and image solidity, a high degree of refinement and grace in the sound, and a great sense of rhythm. In Class A operation, the Trilogy 994s come extremely close in most of these key performance aspects.

The difference is the Trilogy are hybrid designs, aren’t as richly finished and you won’t face an 18-month-long waiting list to own a pair of Trilogy 994s. The Trilogy 994s also cost one-eighth as much as a pair of K-160s. Over 95% of the performance for 12.5% of the price sounds like a pretty good deal. They meet the same target audience: those who think most modern audio systems are too brash and forward. And if you think most modern audio isn’t pitched forward and a little bright, you’ll still respect Trilogy’s refined sound, even if that isn’t your preference. If something’s good enough that those who aren’t in its sonic wheelhouse still appreciate what it does, you know that’s a bit of a winner.

No hair shirts

Good preamplifiers are often the most ‘hair-shirt’ in approach. The Trilogy 914 is a rare exception: a tremendous sounding preamplifier that allows a lot of user control. But even the 914 pales compared to the 994s. These are some of the best-sounding power amplifiers I have ever heard, irrespective of price. The combination works exceptionally well, too.

I’m usually pretty good at second-guessing the price of a product based on its performance, build, weight and so on. I’m generally correct within a ±10% margin. So, here’s a perfectly good £25,000 preamp paired with a pair of £40,000 per channel mono power amps (which sound like £160,000 per channel mono amps with the wind in the right direction)… that happens to be £13,000 and £10,750, respectively. The Trilogy 914 and 994 amplifiers are the best little secret in the audio world.

Technical specifications

914 preamplifier

Inputs: 3x XLR pair (balanced), 3x RCA pair (single-ended)
Input impedance: > 40kΩ (balanced), > 24kΩ (single-ended)
Outputs: 1x XLR pair (balanced), 1x RCA pair (single-ended), 1x RCA pair for send/tape output
Output Impedance: 400Ω
Output Gain (to main output): 24dB
Frequency Response: 10Hz-150kHz ±0.5dB
Dimensions (WxHxD): 46.5×11.5x37cm
Weight: 12.4kg
Price: £13,000, $15,500, €16,900

994 mono power amplifiers