Trafomatic is a relatively recent addition to the high-end hifi fraternity and perhaps best known for the £100,000 Elysium monoblocs. This is a Serbian company that exudes quality, detail and perfection.  The Belus power amplifier up for review here might not be as expensive as the Elysium, but at a more attainable £3250 this is no less a product says Janine Elliot.

When I hear the words “Hybrid” I think of conventional looking cars with electric engines and petrol backup; cars that say they have impressive consumption levels, but in reality are never quite as good as you would hope for. So to be sent a Serbian Hybrid amplifier I expected perhaps a Class D plus valves to make it more musical. This amplifier is instead more straightforward Push-Pull (class AB) but with the surprise of a single C3m valve working as a single ended class A voltage gain in triode mode for the first stage.

Exicon ECX10P20 transistors and EXC10N20 MOSFETs are at the output, two pairs per channel, working as four transistors per channel in a mini-paralleled push/pull array.  The 100 watt into 8Ω power amplifier (140W/4 Ω) works as pure Class A for the first 5-6W and then A/B for the rest. Power is provided by a 400VA toroidal with 8 smoothing capacitors per channel.  

Before starting to make amplifiers the company Trafomatic Ltd, set up in 1997, began by making toroidal transformers and electronics for industrial use. From around 2000 they began to make output transformers, only beginning amplifiers in 2007 as Trafomatic Audio, a venture of friends and hifi lovers Saša Čokić and Milorad Despotovic. So, the toroidal transformer and the two high-current chokes in this design are all made in-house, with great knowledge of design, which greatly impact on the sound that this £3250 amplifier produces.  Indeed, this amplifier was packed to the hilt with the transformer, coils and capacitors, with the MOSFETs tightly screwed to the heatsinks at the side.

It is so good to see manufacturers today moving away from the usual ECC83’s, 6550s  and 300Bs. Saša Čokić really likes the C3m valve (along with the similar C3G) and he is presently working on another product using these tubes. This tube has a good life span, guaranteed for 10,000 hours, which would mean 5-10 years if using them for a reasonable time. The C3m is a vacuum pentode looking unlike normal valves with its black metal cover, rather than the usual glass. Whilst I love looking at valves lighting up through the glass covered vacuum, they will always suffer microphony, so a metal cover reduces this making this one of the lowest sufferers and one of the quietest tube you can buy. And, if you don’t like the metal cover you can remove it to show the glass tube, though because the tube is hidden inside this solidly built and heavy metal topped amplifier with side-fins for the MOSFET heatsink, there won’t be much point.

Made by Valvo and Siemens, the C3m tube was intended for the German telephony system which required audio travelling long distances, so they needed valves with high output and low noise. These were never made for general sale, so the Belus uses NOS tubes. The power amp has a gain switch on the back to adapt to any speaker system; ‘normal’, ‘low’ and ‘high’, all derived from different negative feedback values. So, at the ‘low’ setting 22dB of gain is available (with -9dB of negative feedback and 1.2Vpp input sensitivity), and gives the best signal to noise ratio of the three settings, at 90dB. At the medium setting there is 25dB of gain (with -6dB of NFB, 0.9Vpp input sensitivity) and 89dB S/N ratio, and at the ‘high’ gain setting produces 28dB of voltage gain (with -3dB of NFB, 0.6Vpp input sensitivity) and 85dB S/N. Output impedance at 100Hz is 0.01Ω for low gain, 0.0116Ω for normal gain and 0.085Ω for high gain.  I chose to use the unit at the medium setting for the review. The Belus is available in two colours; either black, or silver which has a contrasting brass coloured face plate.

This amplifier looks anything but a valve amplifier; just like those electric hybrid cars looking nothing like I’d expect an electric car to look like. Not that it bothered me in the Belus. This was industrial grade build, something I really liked.

Belus was, so I am told, the son of Poseidon and Libya, one of the demigods and rulers of Egypt. Being half human and half celestial therefore this is an appropriate name for a hybrid amplifier. As Saša told me; “It’s half tube (as God) and half Mosfets (as human!)”. From that I can guess which end he likes best!  Mosfets can have a bad temper and be unpredictable, just like humans, though in the Belus they were very much in a controlled, solid state.

The Listening

I always make sure that I am not influenced by looks and weight; both of which with this product are first-rate. After all, how many times does a good looking meal appear to taste better than a bad looking one! But the quality of work in the Belus was certainly food for thought; I really was impressed by the detail of build in this model. It even arrived in a wooden crate with handles, all screwed up on each side.

First impressions on listening were of class. This was a smooth operator with guts and reserve. Music sounded very real and that valve really fed an honest sound, but perhaps it was just too honest. There was nothing that, through my Graham LS5/9s, sounded radical or risky.  Connecting to hybrid speakers, in the form of the Eminent Technology LFT8b ribbon, planar and 8 inch woofer speakers at £2500, which I was reviewing at the time, gave a quicker sound whilst still maintaining full frequency and excellent noise floor.  Similarly using the appropriate cables was important, too. Ecosse SMS 2.3 give excellent bass and a huge soundstage, so these well-used cables worked well in conjunction with the LFT8b’s.

Rush’s live recording at Kiel Auditorium, Missouri, 14^th February 1980 has been remastered on a 180g RoxVox vinyl. A Canadian band set up in 1968 has produced a number of famous tracks that include a myriad of styles and instruments culminating in a progressive rock of occasionally grandiose height – a mix of Led Zeppelin, Cream and King Crimson. This amplifier played it all with musicality and care, though lacked a certain amount of pizazz that I wanted to hear. This amplifier is more on the cautious side of great; a bit like that boy or girlfriend that you sometimes wish would actually start an argument with you, rather than agreeing with everything you say or do. Whilst still full-bodied, sometimes the music was just too tame for me, though listening to London Grammar gave it a chance to show just how good that C3m valve is in focusing everything. “Stay Awake” from their superb album ‘If You Wait’ (vinyl, again) kept my attention with solid bass and a gorgeous voice. Each individual line of script was perfectly formed and jelled to form a uniform whole. There was a density to the sound that made this amplifier feel it wanted to give its soul to the music.

Listening to the remaster of Dvorak’s Symphony No 9 “From the New World” (Herbert Von Karajan, Berlin Philhamonic, HiQ Supercuts) recorded in the Winter of 1957-8 gave me a chance to test out a very mid frequency emphasised recording, which many amplifiers would give off a very “tranny” sound and rather limiting soundstage. The brass can sound very brash, but this amplifier toned it down to be surprisingly musical and easy to listen to. Similarly “La Maja de Goya” by Granados for three guitars (Opus 3 records, on my aged Ortofon 1980’s Pick Up Test Record) gave a very mellow and pleasing listen, particularly with the guitar’s nylon strings. Similarly the next track on the album of Telemann’s Sonata in C Major first movement for recorder and harpsichord gave a fluid performance, but perhaps just missed out slightly on the gusto that some amplifiers have shown to this piece.

Listening to Dire Straits Brothers in Arms “So Far Away from Me” wasn’t actually so far away from where I really wanted this amplifier to be; detailed and showing no sign of stress, one of the reasons I like MOSFETs in the right setting. But in this Hybrid I did feel that actually the tube was the selling point, those bass thumps and vocal lines and guitars were detailed and performed with an ease and musicality. That C3m tube really does improve things! “Your latest Trick” and “Why Worry” (track four and five) were so laid back I just drank coffee and enjoyed.

Conclusion

I really did enjoy playing this amplifier in the few weeks I had it connected up, and in some respects it reminded me of an iconic amplifier I modded a few years back; full weighted and meaty sound with lots of class. This amplifier is extremely easy to listen to, at both low and high sound levels, and works well with all types of music, only perhaps just a tad too slow for some. However, this does mean this amplifier is epic for long periods of listening, something that cannot be said for many amplifiers.

For £3250 this is actually extremely good value and well worth trying out.

AT A GLANCE

BUILD QUALITY:  Excellent, industrial quality build including even a wooden box to deliver it to you in. 

SOUND QUALITY:  Low distortion and very quiet amplifier offering 100Watts of full-bodied sound, working well at all volumes.

VALUE FOR MONEY:  At just £3250 this is an extremely good valued offering

Pros:

Accurate but slightly laidback musical performance
Low microphony and long-life of C3m tubes
A well thought out design
Works well on all types of music
Solidly built and with good looks

Cons: 

Might be rather slow performance for some; some might prefer a brighter and faster sound.

Price: £3250

Janine Elliot

SPECIFICATIONS

Output power: 2x100W (8Ω)

Class of operation: Push-Pull
(class AB)

Tubes complement: 2x C3m

Inputs: 1xRCA, 1xXLR

Speakers DC protetcion

Input sensitivity: 0.6Vrms , 0.9Vrms , 1.2Vrms (selectable by toggle switch at the back side)

THD %: 0.03% – 1W/1KHz, 2% – 100W/1KHz

Frequency bandwidth: 10Hz(-1dB)-40KHz( -1dB)

S/N Ratio: 88dB

Input inpedance: 100K

Power consuption: 300VA

Input voltage: 230VAC-50Hz /115VAC-60Hz selectable at back side

Size: 360 x 300 x 100 mm

Weight: 15kg