Creek Audio Sequel 54mk 2 (phono stage module for moving coil)
The Sequel 54 mk2 MC Phono pre-amp is the device specifically suited for medium output Moving Coil cartridges, with an output between 0.5 to 1mV and a matching impedance of <120 Ohms.
The Sequel 54mk2 is not suitable for high output MC cartridges, which require lower gain and a higher input impedance.
The Sequel mk2 has two gain stages using low-noise op-amps. RIAA correction is performed both active and passively. The first gain stage matches the MC cartridge’s <120 Ohms impedance and adds gain, without changing the frequency response.
The first stage of RIAA de-emphasis is performed passively between the two gain stages. The mk2 circuit uses a low impedance filter circuit for improved noise performance.
The second gain stage boosts the level further and uses active filtering in its feedback for the RIAA de-emphasis, For improved RIAA accuracy and improved sonic quality, the Sequel mk2 is made with E96 1 % tolerance metal film resistors and 1% tolerance polypropylene WIMA capacitors.
To eliminate coupling capacitors that can negatively affect the sound, a DC servo circuit is used to block DC from input to output and roll-off low frequencies sensibly below 10Hz. There is no rumble filter in this design.
The Sequel mk2 is powered by a dedicated voltage from the integrated amplifier, via its PCB connection pins. Locally, it uses a low noise voltage regulators, whose function is to stabilise the voltage and filter noise from the main power supply. The Sequel mk2 has optimal overload margin for a given gain.