Phonostages — Grimm Audio PW1

The PW1 is the phono preamplifier from Grimm Audio, the company founded in 2004 in Veldhoven in the Netherlands. Co-founder and chief designer Peter van Willenswaard gave it the nickname Phono Wizard, and the unit was announced at the end of December 2024 at EUR 4,800, GBP 4,695 and USD 4,900. It was the first Grimm product in the field of phono amplification.

Key specs that matter

Separate RCA input pairs serve MM and MC cartridges, and the output is offered on both RCA and XLR sockets. In MM mode the RIAA gain is 37 dB plus or minus 1 dB for a typical 5 mV cartridge, with an optional extra 10 dB. The MC path adds 20 dB or 30 dB on top, aimed at cartridges of about 500 microvolts or 160 microvolts, and the total reaches up to 77 dB for very low output designs. The MM input presents 47 kohm and 47 pF, with parallel capacitance of 47, 100 or 220 pF available. For MC the resistive load can be set between 33 ohm and 1 kohm, and the base capacitance of 330 pF can be raised by 330 or 680 pF. Signal to noise is at least 80 dB for MM and between 76 and 80 dB for MC, crosstalk is at least 90 dB for MM and 86 dB for MC, and THD plus noise is quoted at or below minus 45 dB, mostly second harmonic. RIAA accuracy is within 0.5 dB from 20 Hz to 20 kHz. The case measures 100 x 250 x 100 mm and weighs 3.3 kg.

Engineering and use context

Each amplification stage - MC, MM and equalisation - is built around a single active component, followed by a selected op-amp that works as a buffer. The equalisation itself is passive. For the MC front end Grimm chose a low-noise FET with a voltage noise of 0.7 nV per root hertz, which is what makes the high MC gain usable. The internal linear power supply is built around a custom low-noise Amplimo transformer, which removes the need for an outboard supply, and a copper sub-chassis inside the brushed black aluminium case provides shielding. Gain and loading settings sit on the underside of the unit. The rear carries a master power switch, a ground screw and an IEC mains socket without a safety earth pin. Grimm backs the PW1 with a 5-year limited warranty.

Pairing

The wide gain range and loading menu allow one turntable to run either a standard MM cartridge or an ultra-low output MC without a step-up transformer. Preamps and integrated amps with balanced line inputs can take the XLR signal, while the RCA pair covers conventional single-ended inputs.

Alternatives

Grimm Audio lists no second phono stage, so the PW1 has no sibling of its kind in the catalogue.