As I already mentioned once (in the review of Wow Audio Lab L1/M1 amplifier), the Audio Show in Warsaw is a place for me to collect information. Not necessarily about the sound but rather about brands, products, and people. But I always welcome a nice surprise, I mean a really good sounding system. Such a system, such a presentation is usually awarded by us with the Best Sound Audio Show. Such an award in 2014 was given to a system that included a product of a British company Trilogy Audio, and one can find it mentioned next to their hybrid integrated amplifier 925 on the company’s website. To be clear – this system, with this amplifier, delivered a truly delightful presentation during the Show, so the Award was no coincidence.
Trilogy was founded in 1992 by Nic Poulson and from the very beginning, power supplies of their devices received special attention from designers. This might be obvious today, but at the time, power supplies were rarely at the center of interest of audio equipment designers. Nic knew what he was doing – his professional background (working for BBC, designing runway lighting systems, and others) gave him enough knowledge and experience to ensure that. Since power supplies were that important for him, it was a natural move to start another company that would focus its activity on designing devices and accessories improving the quality of the current fed to audio systems. And so he was a co-founder of a company called Isotek. Little is known about the reasons, but Nic left Isotek in 2001 to start his own company ISOL-8. It’s a sister company to Trilogy Audio. If you take a look at Trilogy’s webpage, you’ll surely notice that there seem to be a few blank years in the company’s history between 2001 and 2008. It seems that it was a period of hibernation for this company. Before that, Trilogy offered tube-based devices. And then, in 2008, they came up with the first hybrid design, an integrated amplifier called 990. After that, new products were launched, but it seems that it never has been done in a hurry. A phonostage, 907, was launched in 2010, a headphone amplifier, 933, in 2012. 2013 was a year when a new hybrid integrated came to life – the 925.
It is a fully balanced design, with a preamplifier section based on two double triodes 6H6Π. As one can read on the manufacturer’s webpage, these particular Russian tubes were chosen for their “high transconductance and very high linearity”. A carefully optimized servo ensures the tubes operate perfectly symmetrically. The output stage works with no negative feedback loop and it’s based on two types of transistors – MOSFETs and bipolar ones. The former operate only within the first watt, in class A. The latter operate up to a few watts also in class A and then they start to work in class AB, in push-pull mode. The device looks really solid. Operating it is something nerds will love. After turning the amplifier on, one has to input a unique PIN before one can start to listen to the music. The amplifier has a sophisticated monitoring system to maintain safe operation at all times. Temperatures and critical voltages report to a dedicated microcontroller. Proprietary formulated algorithms monitor output current against time and frequency with great accuracy. This enables reliable discrimination between DC faults or demanding musical conditions, providing excellent protection but avoiding unwanted shutdowns. Despite the fact that it is a classic integrated amplifier, it is also a user-friendly one. Users can label inputs and set a sensitivity of each of them separately to equalize different signal levels from different sources. Settings of volume and channel balance are stored in the device’s memory so the next time the device starts, it uses the same settings. Remote control allows users to change phase, but it can be set also in the amplifier’s menu. A proprietary external communication interface, TAS link, allows 925 to communicate with the outside world and other Trilogy devices. A real-time clock provides a multi-event, seven-day system that allows users to pre-program an activity of the amplifier: it can turn on or off the device at a set time on any day of the week using TASlink. Users might use this system to turn the amplifier on some time before a listening session, thus allowing a warm-up time. A sleep function provides power down after a selected period of the user’s choice. Other Trilogy products can be “Named” via TAS link for status monitoring and remote control. Any intelligent features will then be available for use or monitoring via the 925. A wide range of user-programmable defaults are possible, including setting the home page display and PIN protected control menu locking. This amplifier was used as a part of my reference system, and additionally with the Compact Disc CEC CD5 Player, that was used also as a DAC receiving signal from a PC. As a power cable, I decided to use the Crystal Cable Absolute Dream. Along the amplifier, users receive a small, plastic, not particularly nice looking remote. If one wants something better, it’s an optional purchase – a very good looking, user-friendly Personal Remote Control (PRC). I believe that it is an integral part of the 925 experience, so one should simply add it to the bill – one shouldn’t regret it.
From a designer’s point of view, an integrated amplifier has a lot of advantages from a sonic point of view. You can keep the signal path really short and the current loops nice and tight. You can often miss out on an extra stage of amplification compared with a pre-power combination too. The only area where you have more restrictions is the physical size; you have to package everything in one chassis. That gives you a ceiling for output power because you need to shift the heat of the output stage and you have a size limit on the power supply. I didn’t want this restriction to limit the everyday performance of the amplifier at all, so we made the 925 as good as it could possibly be within its power envelope. I wanted the amplifier to be fully balanced, even right through the output stages and drive to the loudspeaker. Some amplifiers claim to be balanced, but they get converted to single-ended somewhere along the signal path. The signal positive and signal negative are never tied to ground in the 925. This keeps big currents out of the vital ground reference, and the whole signal path is fully symmetrical. The gains in small signal resolution and dynamic composure are worth the extra complication of doing everything twice; once for the positive phase and once for the negative phase. It also means we could do absolute phase inversion as a feature. I observed long ago that if everything else is equal, zero feedback amplifiers have better musical flow and less listening fatigue because the harmonic structure of the amplifier varies less under the different drive conditions the music demands as it plays. The input stage uses a pair of 6H6П triodes for Class A voltage gain and the output stages use our unique MOSFET and bipolar topology for current gain, so the amplifier has no overall feedback. Trilogy opens for its owner a similar path of development. It is a device with a soul, with a beautiful soul. All that is left to do for its owner is to choose other elements of the system offering a similar set of sonic features. In this case, when it comes to particularly sophisticated performance, adding on even more sophistication will never hurt. It will only intensify the best features of the performance.
One of the key elements of this performance is an outstanding differentiation this amplifier delivers. It is this type of differentiation that “supports” understanding of played music. It is not about bringing more details to the surface. Surely they are all there; nothing’s lost or hidden. What you get is an impression that all these details serve a purpose of emphasizing interactions between sounds, instruments, and planes. Lots of details presented as a way of making distinctions between different elements of the music don’t work well; it separates elements of music. Trilogy delivers plenty of details, lots of information, but they all are there to serve the “bigger picture”, to serve the music. Tonal balance is very accurate, so it’s not really a “warm”, nor a “cold” sound. If you put a gun against my head to make me choose, I’d probably say: slightly “warm” rather than “cold”. But one gets this impression not because the leading edge is softened, or roll-off of treble, but because of how rich and dense the sound is. That’s probably what makes most recordings sound so well with this amplifier. At least as long as they make some “musical sense”, if there is something more to them than just a “surface sound”, if there is some depth in them. That is why I enjoyed so much _Bemowe frazy_ by Bemibem. This record was originally released in 1974 and recently it was remastered by Ms. Karolina Gleinert. It’s a fantastic recording, also because Tomasz Jaśkiewicz, who had left Niemen’s band three years earlier, played guitar there. I knew that this recording offered a very interesting sound, but with Trilogy, it was only a second time (the first was with my own system) that I could fully realize how great it was despite the recording’s own limitations. Next to amazing richness and wonderful treble, the British amplifier correctly presented not that rich bass, and slightly “rustling” midrange. But listening, right after that, to new Audio Fidelity remasters of Blood, Sweat & Tears and Eric Clapton, I couldn’t help but admire the quality of Polish producers. Especially considering the quality of equipment they had to work with. Both American recordings offered slightly smothered attack and decay phase, but also deeper sounding vocals. Sounds delivered by this amplifier (assuming it’s supported by a well-matched system) materialize in front of the listener with a wonderful, black background. Such a performance recreates all aspects of the recording including instruments’ acoustics, room’s acoustics, tonality, and non-musical effects caught on the recording, making it sound amazingly real.
So what would be a well-matched system? There are several options. If the budget is limited and you can’t spend 50,000 PLN per system’s element, I would recommend spending most of your budget on Trilogy 925. The next step – speakers. I have to “first choices” here – Harbeth M30.1, or Graham Audio LS5/9. Or some other similar design. As for power supply – the choice is obvious: 925 is designed to work best with ISOL-8 products, and that’s the best recommendation. Other cables could also come from the UK – I’m thinking Tellurium Q should do a great job here. If you’re vinyl fans, I can see two options. The basic one would be Kuzma Stabi + Stogi S. That’s a beautiful, wonderfully sounding turntable. If the design is too modern for you, another choice would be the Funk Little Super Deck, a deck that was a part of a system awarded by us during Audio Show 2014. But if you could spend more, then Avid Acutus SP should be a great choice. If a digital source is your choice, then a natural partner for Trilogy could be (coming from the same distributor) Lumin T1 or (more expensive) S1 music server. If you are, like me, CD aficionados, then the CEC CD5 might do the trick – don’t be fooled by its price! Later you could always purchase the Aurender X100L music server and hook it up using USB input in CEC.
Considering its price, I can’t really see anything that could still be improved. Even with double the price tag, I’d still have to think really hard to point out some space for improvement. It’s easier for me to define Trilogy’s sound by comparing it to my, costing over 300,000 PLN, reference amplification. When compared head-to-head, they delivered similar performance in terms of tonality and impressive, TNT-like dynamics. My Austrian-Swiss tandem, which I am so proud of, creates deeper, more palpable images, and is able to differentiate textures even better than 925. But switching from my system to Trilogy clearly shows that there is no huge gap between their performances – my system is simply slightly better. The only obvious advantage of my system is its ability to create significantly deeper, more natural soundstage. Trilogy builds a wonderful soundstage too, but it is more focused on whatever is going on in the front of the stage. Model 925, a pinnacle of Mr. Poulsen’s professional life, is an outstanding device. It’s a fabulous design, one of the best I’ve ever seen, and it delivers glorious performance too. As for an integrated amplifier, it’s not particularly big, looks good, and is user-friendly. I gave you a recipe to build a top performance system around it. If you can afford it, you could also build a much more expensive system around 925, with other elements even from a 100,000 PLN price range, or even more. It seems as the sky is the limit for this remarkable integrated. It is pure high-end, an amplifier for a lifetime… Trilogy 925 is a device created by an experienced designer for people who want to feel special and require a certain level of convenience when using their special devices. So 925 is not another “big box” that users have to fight all the time to get it working. It is a rich-feature, customizable, user-friendly integrated amplifier. Let’s start with the colors of its casing. It is made of high-grade aluminum and offered in one of five colors: “Sunburst Yellow”, “8C Red”, “Mediterraneo Blue”, “Nero Carbonio”, and “Iron Grey”. These fancy color names try to describe a particular color in the best possible way, and you have to admit it, they also sound cool. There is another British manufacturer who uses a similar strategy – Roksan (also from London). Their K3 series devices are offered in colors like: “Opium” (dark brown), “Anthracite” (silver), and “Charcoal” (black). Casing is built up with aluminum elements – thick slabs and extra-thick radiators. The front panel seems minimalist, so it is hard to believe that a manual for this device has the form of a thick book. It is so because the device is highly customizable. Also, all safety guards are very elaborate. Apart from many commonly used customizable settings like changing inputs’ label, changing phase, or display dimming, Nic Poulsen thought about many other useful features. The amplifier is equipped with a “real-time” clock that allows scheduling certain activities of the amplifier so each day of the week. The amplifier, or the whole system (when using TASlink), can automatically turn on or off according to a pre-programmed schedule. One can program the amplifier to turn on some time before the planned listening session, so that when the time for the session comes, the amplifier/system is already warmed up. An access point to the whole menu is a large volume control knob that is also used to operate the menu in conjunction with three small buttons. The large, red, readable display is very helpful too. The back panel sports an abundance of sockets. There is a clear division between the right and left channel. There are three balanced inputs – there are Neutrik XLR sockets. The whole amplifier is a balanced device. The output stages are arranged in a bridge configuration and large currents are kept out of the system ground. There are also three single-ended inputs with very solid sockets that look as they might be coming from Mundorf. The same manufacturer (most likely) delivered solid speaker posts. 925 also sports a pre-out (RCA). Next to it, there is an Ethernet (RJ45) port, used for communication between Trilogy devices using TASLink protocol. You can always try connecting 925 with devices from other manufacturers – there is still a chance that they will be able to communicate despite different brands. The amplifier is delivered with an ISOL-8 power cord and it was used during this test. Inside, one will find even more elements from Mundorf, like polypropylene capacitors coupling the preamplifier section with the output stage. 925 is a hybrid design with a tube input stage, and solid-state output. Tubes in the preamplifier section are Russian 6H6Π (6N6Pi), at first glance quite similar to popular 6H30 Π (6N30Pi), used, among many other devices, also in my Ancient Audio CD Player. There are two NOS triodes working per channel, manufactured in the Soviet Union in Novosibirsk. The output stage is a Nic Poulson’s proprietary design. It combines the advantages of MOSFET and bipolar transistors. The output devices are configured to operate in a high bias state, giving a generous envelope of Class A operation. The relatively high dissipation, in conjunction with the high thermal inertia of the heatsink, keeps the devices in their optimum operating condition and improves sound quality. The fast, agile FET only operates within the critical first watt region. The bipolar transistors then seamlessly contribute high current when music conditions demand. It reminded me of the Devialet that sports a small, analogue amplifier operating in class A, combined with a powerful class D amp. Trilogy uses two analogue amplifiers though. The signal’s path is very short. Three fully balanced and three single-ended rear panel inputs are switched via instrumentation grade ruthenium plated relays within millimeters of the rear panel connectors. A separately selectable auxiliary loop is provided. In addition, a 3.5mm jack on the front panel allows portable sources to be connected quickly and easily. A carefully selected audio grade digitally controlled potentiometer provides volume control and balance in 1.0dB steps. Conventional extruded heatsinks display strong resonant signatures and have been rejected in favor of custom, machined solid billets of aluminum. Each weighs in excess of 5kg. Their high mass and irregular form provide outstanding mechanical and thermal stability for the output devices. Trilogy 925 sports three power transformers. One supplies the output stage, one the preamplifier, and the third logic circuits. The power transformers are mounted on a thick machined plate of K-material (the same one is used inside ISOL-8 power conditioners). This high metal, low resin content composite has excellent mechanical properties and superior self-damping to metal. It provides additional damping and stiffening of the non-magnetic chassis too. K-material is also used for the feet, providing the optimum interface between the 925 and the equipment support. Custom (Mundorf?) Trilogy reservoir capacitors smooth each channel of the output stage DC and valve HT supplies. This is an outstanding piece of engineering. All aspects of the design were carefully thought through. While the signal’s path is extremely short, the rest of the circuit is very complex, just like in my Soulution 710 power.
Rated power (@ 8 Ω): 2 x 135 W Input impedance (single-ended): > 42 kΩ Input impedance (balanced): > 84 kΩ Distortion: Less than 1% A weighted at rated output Frequency response: 10 Hz-50 kHz (+/- 0,5 dB) Input sensitivity: 600 mV RMS (for rated output) Dimensions: 445 x 430 x 127 (WxDxH) mm Weight: 20.5 kg
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