Available in MM and MC versions with the PSU1 power supply or the new PSU1 Enigma power supply (MC only)
Record Equalisation Isn’t What Most Think It Is
Its design recognises something virtually all other phono preamps don’t – that record equalisation isn’t what most think it is!
Record equalisation is quite a convoluted process complicated by historical and physical technical limitations – for records to work at all required some considerable compromises simply to cut and press the groove.
This is why record EQ exists and why the phono preamp has the job of correcting it.
But there’s something else contributing to the EQ which the phono preamp has to correct — the actual cartridge being used to play records has a rising response.
Here we’re not talking about something subtle — it is a real rising response few understand — the cartridge output is rising at a rate of 6dB per octave, a 45 degree slope, and it’s completely different to the EQ applied to the record.
Even so, ever since the magnetic cartridge came on the scene — the cartridge type we all use today — phono preamp designers have looked at the combined EQs of record and cartridge as being one.
The Accession Hi-Fi Phono Stage Preamplifier Changes It All
Treating the two quite different EQs separately, the Accession first strips away the cartridge’s contribution to the frequency response. It then deals with the record EQ.
Thinking about it, the record’s own EQ was applied when the record was recorded, and even if you just bought the record you’re playing today that event happened some time ago — whereas the phono cartridge is applying its rising response in real time now as the record is playing — these are two completely separate events in time.
It provides 4 cartridge loading options: 1] the standard 100 Ohms many MC cartridges are specified as; 2] 300 Ohms. Why? because it is logarithmically the double of 100 Ohms and our hearing is logarithmic; 3] 500 Ohms – the maximum the design can do without compromising noise; and 4] 75 Ohms by selecting both 100 and 300 Ohms.
A manual volume control active on the variable “var” outputs which can be used if the Accession MC is to drive a power amp directly. Required power amp input sensitivity will depend on the cartridge output, but a 0.3mV cartridge will cause around 350mV at the variable outputs. Also note this volume control can go fully clockwise without adding distortion to the Accession MC outputs (awesome!)
RIAA is the standard recording EQ for most records, so that’s right-hand switch down. But you might have (or could obtain) some older long playing classics from the 1940s and 1950s recorded to NAB or FFRR – those were the most popular American and British EQs before RIAA. And what is CA/Flat? It’s what the record really sounds like without any equalisation: it is the Constant Amplitude output after applying the Accession’s cartridge equalisation to make it Flat.
Adding left and right channels together and dividing by two means mono records played on a stereo cartridge will sound mono, and that’s what the Accession mono switch does. Use it to remove the left-right swaying effect a slightly eccentric mono record can have. This A+B/2 switch will not render stereo as true mono, giving a “tunnel” effect to stereo sound, so ensure it’s switched up when playing stereo records.
Recording while you listen
The variable output can also be used to feed a digital recorder (or even a tape recorder!) whilst you listen to the record via the fixed output into your line preamp, integrated amplifier or receiver. Use the volume control to set the right input level into your recording device. Quite often a fixed output level is too “hot” for a digital recorder’s analogue input and results in hard clipping. Turn the volume control down so you get just the right recording level.
The very best of EMC protection
The shielding provided on the Accession MC safeguards against the intrusion of unwanted electro-magnetic disturbances, which at best would colour the sound and at worst you’d hear interference from other devices. Make sure you use properly shielded interconnects with it so interference hasn’t a chance. Our range of interconnects will help you achieve additional immunity.
Unobtrusive compact design
Our eurocard 1U height cases save on space so you can have more things to enjoy without the worry of where to put them. They will stack on top of each other and will even work on their sides. They’re remotely powered so won’t make other sensitive items hum or buzz.
The Accession MC uses (and is supplied with) our PSU1 power supply which should be placed off-rack, keeping transformer influences away from your sensitive equipment, and most importantly well away from your pick-up cartridge. Remote DC power is the most sensible way to power sensitive equipment. There is no transformer inside your Accession MC to worry about, and no AC on its low voltage cord to induce hum into adjacent cables.
The Features And Their Benefits
The package of features the Accession phono preamp provides makes it really flexible allowing it to fulfill a number of roles.
- Adjustable and fixed level outputs
- Volume / output level control
- RIAA, NAB (American) and FFRR (British) vinyl record EQ’s
- Flat / CA (constant amplitude) alternative EQ
- Mono / stereo switch
- Four cartridge capactive loading options: 100pf; 220pf; 320pf and “out”
|Input and output connectors||360° shielded RCA/phono sockets, hard gold plated|
|Input sensitivity range||0.125mV to 0.84mV (recommended)|
|Output range (for above inputs)||145mV to 975mV|
|Maximum input||4.2mV rms|
|Maximum output||4.876V rms|
|Gain||61.3dB (1161) at 1kHz|
|Input impedance||500, 300, 100 and 75 Ohms (300 plus 100 both on)|
|Output impedance (driving impedance)||750 Ohm fixed OP/ 470 Ohm variable OP (will drive ≥10k Ohms)|
|Noise at output||-65dB A wtd. 20Hz to 20kHz 0dBu out|
|Distortion||typically 0.02% 20Hz to 20kHz|
|RIAA accuracy||± 0.3dB (sampled)|
|Frequency response||20Hz – 100kHz (±0,−1dB normalised)|