SPL Phonos RIAA Phono Preamplifier

Phonos is a pre-amp for turntable players with moving magnet (MM) and moving coil (MC) pickup systems. The equalization curve is according to RIAA and suitable for all records since 1954.

This phono preamplifier is equipped with the best sounding capacitors and built according to the legendary Douglas-Self-Design.

The adjustment parameters are designed as switches and are always accessible so that you can playfully reach the best sound results.

MM And MC

There are two primary methods that modern pickup systems use to generate power: moving magnet (MM) and moving coil (MC).

Moving Magnet

Moving Magnet pickups produce a rich, smooth sound. The movement of a magnet between copper coils creates a small voltage. MM pickups have a very high inductance and impedance. The latter can be adversely affected by the cable capacitance and alter the linear frequency and phase response.

The Phonos offers the choice of four capacitances to correct the linearity of the frequency and phase response, as well as to increase the high frequency range at will. The capacities are 150pF, 220pF and 330pF. In the off position, the capacity is determined by the capacity of the cable.

Moving Coil

The MC pickup is also a small electromagnetic generator, but with the magnets firmly anchored and the coils moving in between, just the opposite of the MM pickup. However, the output voltage is very small at only a few hundred microvolts and is therefore more sensitive to noise and induced hum, etc. This makes the preamplifier design a challenge because the very low output voltage must be preamplified extremely noise-free. With up to 71.5 dB of pre-amplification, Phonos offers one of the most powerful phono pre-amplifiers for MC systems, which is extremely low-noise, linear and phase-locked thanks to the 120V technology.

MC pickups have a very low inductance and impedance. This means that the effects of cable capacity (from turntable to preamp) are negligible. The impedance, on the other hand, is relevant and can be set in six positions: 100, 220, 470, 2.2k, 4.7k, and 10kOhm. If there are any doubts as to which impedance corresponds to that of the pickup, the impedances can simply be switched through until the linear frequency response is determined acoustically.

Subsonic Filter

The rumble of the drive mechanism of the turntable is enhanced by the high gain of the bass range through the RIAA equalization in the playback. The Phonos offers with the switchable Subsonic filter the possibility to remove this rumble.

Gain

The preamplification can be switched in three values. The normal gain value is + 46dB for MM and +67 for MC pickup systems.

In the -10dB switch position, the Phonos produces enough output level for normal hi-fi equipment operating at a -10dBV reference level.

In the + 4dB switch position, the output level is about as loud as that of modern DA converters at a reference level of 0dBfs = + 15dBu.

RIAA Equalization

RIAA equalization is a specification for the recording and reproduction of records proposed by the Recording Industry Association of America (RIAA). The RIAA equalization curves established a global de facto industry standard for vinyl records from 1954 onwards.

The purpose of RIAA equalization, which is a form of pre-emphasis in recording (cut) and de-emphasis on playback, is to extend recording time by reducing the groove width, improving sound quality and reducing the risk of damage Grooves in the playback.

When recording, the low frequencies are reduced and the high frequencies are raised and during playback exactly the opposite happens. The result is a linear frequency response that reduces high-frequency noise such as hiss and clicks caused by the playback medium.