OMAK JEWEL ONE Thermonic Amplifier
HI-FI WORLD, July, 1995, p 3.
- Russia is going to be a strong player in audio. Forget Rigonda, we're talking about serious kit like the Omak. It uses C-core transformers -difficult to build and sophisticated. We were impressed - the Russians know what they doing. With low labour costs, Russia will become a powerful player in the next decade. o From Russia with love, courtesy of Air Ukraine, comes the Omak valve power amplifier. Built like a T27 tank, it's impressive. We don't commonly see such characterful or effective products.
HI-FI WORLD, July, 1995, р 4.
OMAK JEWEL ONE. It sounds like a character from Blake's Seven, but the Omak is a burly Russian valve amp, auditioned here by Dominic Baker
HI-FI WORLD, July, 1995, р 34.
Built like a Russian tank, Omak's Jewel pre-power amplifier is a hefty chunk of metal. The massive alloy rack case of the power amplifier, housing kilograms of transformers, arrived in a sturdy wooden case (presumably to stop it doing damage to anything else it travelled with) stamped "Air Ukraine". The Russians aren't the most commercial when it comes to hi-fi, but the Omak, obviously hand assembled, was extremely tidily put together.
I guess it's no surprise that one of the first Russian amplifiers we've seen is a thermionic design, Those familiar with valves will know Russia is one of the few countries that still produces them, with Sovtek in St. Petersburg well known for the quality and reliability of their valves.
Omak's ?899 Jewel One power amplifier is a chunky design using the powerful EL509 line fly back (TV) pentode in push-pull configuration. Unlike many valve amplifiers though, with this you needn't worry about your loudspeakers. The Jewel One produces 5Owatts into 8 Ohm and 8Owatts into 4 Ohm thanks to the high emission current of the EL509, enough to drive most loudspeakers including Quad electrostatics.
The ?250 Jewel Two preamplifier is a simple passive affair with separate record and listen selectors making home recording easier and more flexible. There is provision for five line inputs and volume is controlled by a precision 24-step attenuator. The importers aren't sure whether they will be importing the preamplifier yet, but suggested that if they did, it would be available as a package with the power amplifier at the very reasonable price of ?999.
With its heavy build, pro-style grab handles and high power I was half expecting the Jewel One to be a scaled down PA amplifier. But when I first powered it up, it showed just how wrong appearances can be. The Jewel is as sweet and gentle as the sugar plum fairy herself, with an impressively large but warm, sweet sound. There's a subtle grace to the way the Jewel carries along music, Sherryl Crow's silky vocals were richly textured, the Omak capturing the mellow mood perfectly.
Pink Floyd's 'What Do You Want From Me' had great weight and power behind it, the bass guitar sending out a shock wave of bass into the room while the lead soared above. The force behind every bass note was quite something, the Omak seemingly having limitless bass depth and power with which to produce it. Dynamically though, the Jewel is a bit blunted. The notes are full and tonally smooth, but the blow is softened a little too much, meaning the Omak can sound a touch sluggish. The leading edge crack from drums was dulled and drawn out, and lower notes bloomed larger than life. It wasn't an unpleasant effect and could well make this the ideal remedy for systems in need of warmth and body.
Moving to a harder, more snappy recording, the Omak gave a far more convincing performance. Blur's Parklife gave it something to get its teeth into. Although no less impressive in terms of scale and power, the crisper recording gave it less time for indecision. 'London Loves' had good attack from its electronic bass line, and Damon Albarn's voice had just the right balance of warmth and clarity, giving good projection without becoming uncomfortable.
Swapping to a less efficient Measured Performance see loudspeaker than the Audiovector 6s I'd started with, and to classical music, its minor blemishes became more apparent. When pushed hard with a full-scale orchestra some grain set in. It was a curious effect, not the normal sharp or gritty distortion of solid state, or the more euphonic tonal unbalancing you get by pushing a valve to hard, but a sharpening of tone and a blurring of the image through the upper midrange. It was almost as if the Omak went out of focus trying to stretch too far out of its depth of field. But this was deliberately pushing the Omak so if you stick to loudspeakers with sensitivity higher than 85dB in a normal size listening room, you shouldn't run into problems. And at the price you can hardly complain.
The Omak Jewel One has all the characteristics of a good valve amplifier, coupled with the drive and force of a hefty solid state device. Midrange and treble are free from grittiness, while the sound stage is large and open, filling all corners of the room. Although a good triode or single-ended design can reveal more atmosphere around a recording, and a powerful solid state amplifier has more control with greater transient attack and stronger dynamics, the Omak is a superb compromise. It combines some qualities of both technologies in a package very attractively priced in comparison to its competition, and powerful enough for any modern loudspeaker. I can't think of another valve power amplifier within ?500 of the Jewel One that offers anything like as much.
WORLD VERDICT - A lot of amplifier for the money and a big, warm, sweet sound place Omak ahead of most.
HI-FI WORLD, July, 1995, р 107.
OMAK JEWEL ONE Test Results
Omak's Jewel One is an impressive beast. It uses a pair of EL509 output valves coupled to a massive 'C core output transformer to produce 50 watts into 8 Ohm and a sturdy 80 watts into a 4 Ohm load. This is an impressive performance for a valve amplifier, and makes it one of the few that will drive just about any loudspeaker, Quads included.
Response extends well down too, reaching 3Hz in the bass. More impressively the jewel One managed to swing full output at 20Hz, so I'd expect plenty of bass slam and power. Distortion was low too, at 0.026% with a I watt signal at 10kHz, which should ensure a clean sound.
Elsewhere the Omak Jewel One continued to show quality engineering with wide separation, extremely low noise and an input sensitivity of 550 mV allowing a passive volume control to be used with CD and other sources with a healthy enough output.
|Power ||50 watts |
|CD/tuner/aux. || |
|Frequency response ||3Hz-30kHz |
|Separation ||80 dB |
|Noise ||-110 dB |
|Distortion ||0.026% |
|Sensitivity ||550 mV |
|DC offset ||0 mV |
HI-FI WORLD, July, 1995, р 56.
- My system comprises
- Systemdek IIX/Moth/Sumiko Blue Point
- Meridian 200/203
- Akai GX4000DB Reel to Reel
- Audio Research SP8 pre-amp
- KEF 104/2 speakers hooked up with Cable Talk wire
- The power amplification is a Mission Cyrus II/PSX
The system gives a detailed, warm and musical sound but the upgrading itch has returned and I need your advice. Whilst the Cyrus has never sounded better, the obvious thing to do is change to a different (valve) amp. What would suit this combo (new or second-hand)?
Answer ...........Try auditioning the Omak Jewel One power amplifier, which is imported from Russia. This has a big, sweet sound with terific bass.