Tom Evans' line of phono preamplifiers, linestages, and amplifiers have earned him a reputation worldwide as a designer of uncommon skills. Like Ferdinand Porsche, his designs are marked by elegant solutions to complex problems. None of these are 'me too' products. None of these designs are rehashings of old thinking with a few 'audiophile' parts thrown into the mix. Taken as a whole, they are designs of genius.
Listen to a Tom Evans system, and you'll know that there has never been a better time to be in possession of a large music collection.
TOM EVANS AUDIO DESIGN PHONO PREAMPLIFIERS
Following the success of "The Groove" phono stage, it was realized that the price of the original placed this technology out of the reach of some listeners. Rather than compromise on components "The MicroGroove" utilises the same basic circuit topology as its predecessor, i.e. a low noise Class A front end device providing gain, feeding a passive equalisation circuit, followed by a phase error correction circuit with an active DC servo around the correction stage to roll off subsonics and DC offset. To reduce costs, both channels are built onto a single board powered by a single power supply. In "The MicroGroove+", the proprietary discreet Lithos regulator is included to greatly improve the quality, transient response time, and noise figures of the voltage rails supplying the whole board. This brings the benefit of CD-like dynamic range, neutrality, resolution and the ability to clearly define the edges of notes and the spaces between. This provides the listener with a far more accurate and dimensional representation of the original performance.
*Each MicroGroove and MicroGroove+ is hand built to your specification in Great Britain. All impedances and cartridge output voltages are available to order. The MicroGroove is upgradeable to MicroGroove+ specification, and loading and gain settings can be changed at the factory. Any phono section which features user adjustable gain or loading will suffer audible degradation of the performance, no matter how such changes may be implemented.
Prices: The MicroGroove-$1050
The Microgroove X $1192 The MicroGroove+-$2100
The Groove RIAA stage is the result of over 10 years R&D into disk replay. In developing the Eikos CD player, Tom argued that as long as the voltage regulators supplying the board were noisier than the quietest passages recorded, and their transient response time was slower than the devices were capable of, there was no point in improving the circuit topology until these fundamental problems were solved. Two years later, he had developed the Lithos voltage regulator, a milestone in musical reproduction. The device is 53 times faster, 1000 times quieter, and 5 decimal places more accurate than the previously 'best' regulators available. Thus was laid the foundation for The Groove phono stage. The Groove is a dual mono design. Channel separation is therefore limited only by the specifications of the cartridge used. At the front end, Tom has used very low noise I/Cs (less noise than a 50-Ohm resistor). This stage is followed by a passive RIAA EQ circuit. The third stage is an ultra linear gain amp; around this he has placed the active lower frequency filter to roll off subsonics. The fourth stage is the output stage, which is capable of driving several meters of interconnect. The case, if made of any metal other than copper, would have a deleterious effect on the sound quality, as field effects of even non-ferrous materials interfere with electron flow. For this reason, the casework is of Perspex, a material with no inductive capacity. The Groove+ is a Groove with a severely uprated power supply (larger transformer, increased smoothing caps, and an extra layer of Lithos regulation between the standard unit's internal daughter boards and the mains), which makes a substantial difference. The four layers of isolation allow a -180dB noise floor."The power supply makes instruments more solid, but avove all, more natural. It brings the music presence" says Roy Gregory in Hi Fi+. Truly fabulous.
Prices: The Groove $4000
The Groove X $4725 The Groove+ $7600
The Groove + SRX (adjustable load and gain) $8900 Groove to Groove+ upgrade: $4600
TOM EVANS AUDIODESIGN PREAMPIFIERS
The role of a preamplifier is to act as a switch controlling the signals from the various source components in a system, and to provide adjustable gain to the power amplifiers. On the face of it, a straightforward task-a switch, a volume control, and a modest amplifying stage. A classic case of easier said than done. We must not forget that anything added to (or left out of) the signal by the preamp is necessarily going to be increased by 20-35dB in the power amps.
Like The Groove phono stage, The Vibe has been in development for the last 12 years. Its basic specifications comprise: *5 pairs of switched line inputs and 1 pair of buffered record outputs *2pairs of outputs to power amplifiers *Function switch from 'WASP' manufacturers of battlefield communication technology *The DACT switched attenuator used in The Vibe has a tracking accuracy between channels of 0.05 dB, compared with an error of ± 10% from other manufacturers. It comprises an array of surface mount metal film resistors mounted on a gold plated spiral track giving 24 positions. It's main benefits are: minimal distortion over a wide bandwidth, short signal paths, stunning attenuation accuracy figures of 0.05dB between channels. *Proprietary 'Lithos' regulation (unique to Tom Evans products) supplying all stages of the circuit
The output stage utilises current feedback technology. This approach is superior to voltage feedback designs as it offers far greater rise and recovery times (less than 10 nanoseconds). Using conventional voltage regulation, this approach is rarely used as power supply related noise creates a marked reduction in resolution and dynamic range. Historically feedback has been used to solve problems of inadequate circuit design. This is certainly the case using conventional technology. Intelligent use of feedback is a key feature of producing a more lifelike presentation, as it greatly improves linearity and bandwidth. The application of Tom Evans' proprietary Lithos regulation means that one is no longer reliant on the amplifier's ability to reject garbage, as this is disposed of long before it reaches any gain stage. Noise is therefore virtually eliminated with the added benefit of increased speed and resolution far in advance of most designs.
Because the gain stage is fully DC coupled to accurately reproduce a wide bandwidth, an added safety feature is a DC detection and isolation circuit. This protects both loudspeakers and DC coupled power amps from potential damage through failure of any source components. This circuit delays power up at 'switch on' for 8 seconds while it checks the system, then remains active at all times during the unit's use, and will immediately isolate the output if DC is detected. This only operates below 3Hz; its presence in the preamp is inaudible. In addition to the current feedback technology, there are marked echoes of the award winning Groove phono stage (in terms of error correcton and the application of psychoacoustic principles) built into the design. The Vibe preamp again moves the goalposts for what is possible in reproducing recorded music.
Add the optional Pulse power supply to the above described Vibe and things get even better. The Pulse consists of two identical boxes, one carrying the transformer while the other provides a large dose of Lithos regulation. These are joined to each other by a short lead, and are joined to the Vibe through the same multi-pin connector used by the stock power supply. Chris Thomas in Hi Fi+ opined that "Even without the Pulse, the Vibe is good enough to be compared to any sub-$17,000 pre out there....But add the Pulse and you are talking of an entirely different level of performance altogether." Shockingly good.
The Pulse power supply is a plug-in power supply substitution to the standard Vibe preamp. No modification to the Vibe is necessary other than disconnecting the stock power supply and replacing it with the Pulse power supply.
Prices: The Vibe- $6000 The Pulse 2(optional power supply upgrade for Vibe)- $4950 Vibe/Pulse 2 combo- $10,950
TOM EVANS AUDIODESIGN AMPLIFIERS (might look like the breadbox, but better than sliced bread)
The Tom Evans Linear A and Linear B amplifiers are truly revolutionary, groundbreaking designs.
Both the Linear A stereo amp, and the Linear B monoblock amps are ultrawide bandwidth designs with vanishingly low levels of distortion. More importantly, unlike some other amps with those same two qualities, these amps are incredibly involving and a joy to listen to.
The Linear A is a single ended, Class A, ultralinear stereo amp with a power rating of 25WPC. Four EL84 tubes per side, in parallel, create a composite tube with characteristics almost identical to the legendary Japanese No.10 tube. The amp measures as an almost perfect model triode, promising to deliver the often sought but rarely realized linearity benefits of triode topology without it's usual limitations.
Paired with an appropriate speaker, this amp can do it all in a way nothing else in our experience has ever been able to do; luscious midrange combined with rarely realized frequency extension. The absence of distortion has to be (not) heard to be fully understood. The clarity and detail retrieval are astonishing, but not at the expense of musicality. It's a combination of qualities we have never heard outside of the two Tom Evans amps. We invite and welcome comparison with any amp in the world, at any price. ---LINEAR A SPECIFICATIONS--- Frequency Response: 12Hz to 90kHz-these are 0dB down points! Flat. Power: 25.2wpc Class A Output Noise: 150dB down 700microvolts(!)(not millivolts) Output Impedance: 0.5 Ohm Input Sensitivity: .7millivolts
Price: $8900
The Tom Evans Linear B monoblock amps differ in design from the Linear A stereo amp. The Linear B is not simply a monoblock iteration of the Linear A. The Linear B is a push-pull fully differential design. Listening comments which apply to the Linear A also apply to the Linear B, but more so.
---LINEAR B SPECIFICATIONS--- Frequency Response: 12Hz to 90kHz 0dB down Power: 50wpc Output Noise: 700 microvolts (not millivolts) Output Impedance: .125 Ohm (!) Input Sensitivity: .7 millivolts
Price: $17,000 pair
Linear A Reviews: In a very comprehensive review of the Linear A and associated Tom Evans equipment, Jeff Day writing for 6moons.com, says"they represent the most startling advancement in the reproduction of music that I have experienced in my home....it also represents the most significant advancement in the reproduction of musical realism that I have encountered short of sitting in with a band....you'll most likely be stunned too when you hear the whole Tom Evans stack of gear playing the tunes....simply the finest amplifier I have encountered in all my years in audio."
You are encouraged to visit the 6moons site and read
the entire review here.Also, Roy Gregory in Hi Fi+ issue 38, says that the Linear A "is capable of a glorious, breathtakingly convincing musical delivery.....one of the biggest bargains out there in high-end audio land."
Rarely has a set of audio components so outdistanced the competition. Anyone in the market for an amplifier owes it to themselves to audition either a Linear A or Linear B. We are quietly and happily confident that it will easily outperform anything else currently available.
