GRAHAM SLEE Accession MC Black phono preamp + Enigma power supply

The Graham Slee Accession MC phono preamp, shown here in Black, embodies all the know-how of the British manufacturer. In a small, compact enclosure it offers a variable output, adjustable loading and several equalisation curves.

GRAHAM SLEE ACCESSION: Overview

The Graham Slee Accession MC comes in a small, compact aluminium enclosure measuring 107 x 50 x 195 mm.

On the front panel there is a volume control that adjusts the level of the variable output, a Mono/Stereo switch, a Flat/EQ switch and a switch for choosing between 3 equalisation curves: RIAA (universal), British and American.

The rear panel provides one pair of RCA sockets + ground (input) and two pairs of RCA sockets for the outputs. One output is marked "Fixed" and the other "VAR" (variable), the latter being directly linked to the volume control. On the left, a DIP switch is used to set the cartridge loading. The 24 V power supply is external. For this high-end phono preamplifier, Graham Slee developed a new power supply to get the very best from its circuit. This PSU-1 Enigma power supply uses capacitors meeting very precise criteria, which filter out "microscopic" current noise.

The PSU-1 Enigma comes with a dedicated DC power cable that outperforms the one supplied with the standard power supply.

GRAHAM SLEE ACCESSION: Technology

While RIAA equalisation is a compromise inherited from the late 1950s, Graham Slee believes that a constant-slope equalisation would be the answer.

Cartridges do not have a flat frequency response. In fact, a cartridge's frequency response rises by 60 dB (a thousandfold) between 20 Hz and 20 kHz. To allow cantilevers to cope with this variation, the RIAA introduced a kink in the middle of the record's frequency response and boosted the low frequencies, and it has stayed that way ever since. Even today, phono preamps apply attenuation as frequency rises, interrupting it over a few octaves in the midrange (the RIAA "kink"), then continuing up to a given cut-off frequency. They treat the whole signal as if it were the "recording curve" (which it is not). And every manufacturer has its own preference: active processing, passive, both, splitting the curve, and so on. RIAA equalisation is the standard used for recording most vinyl records, so the right-hand switch should be set to the down position. However, you may own older LPs from the 1940s and 1950s recorded with NAB or FFRR equalisation. These American and British curves were the most widespread before RIAA came along. Graham Slee also offers a CA/Flat mode. This is the record's true sound without equalisation: the constant-amplitude output signal after equalisation has been applied to obtain a flat signal.

The Graham Slee Accession MC offers 4 cartridge loading options: 75, 100, 300 and 500 ohms.

The Accession also features a "Mono" mode. Adding the left and right channels together and dividing by two gives mono records played with a stereo cartridge a true mono sound. This is what the mono switch does, and it also corrects the left-right swaying effect a slightly off-centre mono record can produce.

The manual volume control, active on the preamp's variable "var" outputs, can be used if the Accession MC is to drive a power amplifier directly. The required amplifier input sensitivity will depend directly on the cartridge's output. However, a 0.3 mV cartridge will produce around 350 mV at the variable outputs. Note also that this volume control can be turned fully clockwise without adding any distortion at the outputs.

GRAHAM SLEE ACCESSION: Sound

From the very first minutes of listening, after 4 hours of warm-up, it is immediately clear that the Graham Slee Accession extracts the maximum amount of information read by a good MC cartridge. Micro-details are fully preserved and the reproduction of ambience and reverberation is remarkable. All this is achieved while preserving timbres as far as possible, without thinning out the sound and without excessive harshness in the upper midrange.

It reproduces even very complex recordings without dynamic compression and without any compression in the lower end of the spectrum. It is very good at preserving the impact of strong transients.

The soundstage is astonishing, easily extending beyond the speakers, and even beyond the walls of the listening room! Yet instrument placement always remains precise and highly realistic.

Operating silence is also excellent. The noise floor is particularly low for a low-output MC phono stage.

The Graham Slee Accession MC and its Enigma power supply deliver remarkable transparency and ultra-high resolution, drawing out the very essence of an excellent MC cartridge. Its neutrality also makes it possible to assess the performance of the analogue system (turntable, tonearm, cartridge, phono cables...) within minutes.

The Accession MC is without doubt a truly high-fidelity phono preamp!

Highly recommended +++

FAQ: Everything you need to know before buying the Graham Slee Accession MC Black + Enigma

Which cartridges should be paired with the Graham Slee Accession MC Black?

It is designed for MC cartridges with a sensitivity between 0.125 mV and 0.84 mV, with 61.3 dB of gain at 1 kHz and 4 loading options: 75, 100, 300 and 500 Ohms. We pair it with the Hana ML MC cartridge, among others. Our cartridges guide explains the different technologies.

Which equalisation curves does it offer?

The front-panel switch gives access to the RIAA curve, the standard for most vinyl records, as well as the British and American curves for older LPs from the 1940s and 1950s recorded with FFRR or NAB equalisation. A CA/Flat mode also lets you listen to the signal without equalisation.

Can it be used without a line preamplifier?

Yes. Its "VAR" variable output, controlled by the volume knob, lets it drive a power amp directly: a 0.3 mV cartridge produces around 350 mV at these outputs, and the volume can be turned all the way up without adding distortion. The "Fixed" output remains available for a conventional connection.

Which power supply comes with this version?

The Accession MC Black is supplied with the PSU-1 Enigma, developed by Graham Slee to get the very best from its circuit. This external 24 VDC / 200 mA power supply combines capacitors selected to very precise criteria with a dedicated DC cable.