Depending on your budget and degree of vinyl playback fetishism, the Grimm Audio PW1 might be a rather high tech phono preamplifier for the best MM and MC cartridges on the market.
Grimm Audio is known for its MU1 streamer and LS1 playback system, an all-digital playback chain. More recently they have released the MU2 streaming DAC and are now entering the analog domain with the PW1 Phono Preamp, both of which were first shown at High-end Munich 2024.
Tip: 2024 marks Grimm Audio’s 20th Anniversary
From Creative Director Eelco Grimm: “..decades ago all founders of the company were so inspired by vinyl that they dedicated their life to developing audio equipment. Even in these days of high-performance digital audio playback systems, it is hard to imagine a future without LP’s. There’s just something magical to it. Since we intend to build the full signal chain, a phono preamplifier was a logical addition. But to be worthy of the Grimm Audio logo, it just had to be something special.”
The PW1
The PW1 has the initials of chief designer Peter van Willenswaard, co-founder of Grimm Audio. Peter spent a lifetime designing and improving phono preamps, both in solid state and with tubes. Of all stages of audio amplification, phono preamplifiers pose the biggest challenges to a designer. With moving coil cartridges, deep bass signals of a mere 50 nV require no less than 90 dB amplification!
Grimm claims that Peter developed a solid-state FET (Field-Effect Transistor) phono preamplifier that matches his best tube-based designs, staying true to minimalistic design principles, using the smallest amount of hand-selected active components, and taking great care of their electronic and mechanical surroundings.
From Eelco Grimm: “The PW1 unleashes the potential of your cartridge with a musicality that allows you to forget that you’re listening to a highly sophisticated audio system, and just let the music enchant you. It clearly carries Peter’s signature sound, which is very spacious, detailed, and open, but at the same time rhythmically addictive and emotionally involving”.
The PW1 offers very flexible cartridge load settings at the bottom of the unit, hidden behind a sliding panel. The power supply is so quiet that it could be built-in, which is unique for a high-end phono preamplifier capable of handling the lowest output MC cartridges.
The PW1 provides both MM (Moving Magnet) and MC (Moving Coil) cartridge phono inputs and RCA unbalanced and XLR-balanced outputs to connect to almost any amplifier or audio system for listening to speakers.
Gain and Load setting controls are placed behind a sliding panel on the bottom of the PW1 (kind of an odd location). Gain settings provide an additional 10 dB for MM inputs and up to 77 dB for MC, accommodating the wide range of available cartridges. Load settings for both MM and MC cartridges provide additional fine-tuning.
Grimm Audio PW1 Phono Preamp Price $4,900 (US)€4,800 (EUR) Design Unique minimalistic electronic design Input Types MC (Moving Coil) and MM (Moving Magnet) cartridges Output Types RCA and XLR Controls Gain and load setting controls are located under a bottom plate THD+N MM ≤ -45 dB (1 kHz, 5 mV)
MC ≤ -45 dB(1 kHz, 500 µV).SNR (CCIR-2k) MM ≥ 80 dB (+0 dB position, ref. 5 mV)
MC ≥ 76 dB (+20 dB position, ref. 500 µV); ≥ 80 dB (+30 dB position, ref. 500 µV).Overload Margin MM 24 dB (1 kHz, 5 mV)
MC 24 dB (1 kHz, 500 µV).RIAA Precision ±0.5 dB 20 Hz – 20 kHz MM/RIAA gain 37 dB ±1 dB
Sensitivity: typical 5 mV.MC Gain MM/RIAA gain plus 20 or 30 dB
Sensitivity: typical 500 µV (20 dB gain) or 160 µV (30 dB gain).Optional Output Boost +10 dB Output Impedance 100 Ω (RCA and XLR) Recommended Output Load Impedance 10 kΩ Input Impedance (MM) MM resistive: 47 kΩ
MM capacitive: 47 pF, plus optional 47 pF, 100 pF, and/or 220 pF in parallel.Input Impedance (MC) MC resistive: 47 kΩ, plus optional 33 Ω, 100 Ω, 330 Ω, and/or 1 kΩ in parallel.
MC capacitive: 330 pF, plus optional 330 pF and/or 680 pF in parallel.Channel Imbalance ≤ 0.5 dB. Crosstalk MM ≥ 90 dB (1 kHz, 5 mV)
MC ≥ 86 dB (1kHz, 500 µV).Interior Copper shielded interior Power Supply Type Internal silent linear power supply. The incorporation of the shielded power transformer results in no need for an external power supply. Dimensions (WHD) 100 x 100 x 250 mm
(4 x 4 x 9.8 inches)Weight 3.3 kg
(7 lbs 4 oz)Warranty 5 years limited 
The Bottom Line
Phono pre-amplifiers are not a sexy product and don’t get a lot of attention from the majority of vinyl listeners who probably use the internal MM/MC phono section included in their integrated amplifier or network amplifier and don’t realize just how important they are.
The main reason that phono preamps are important is that each phono cartridge has unique impedance characteristics and output that require proper equalization if you want to get the best listening result.
Whilst most affordable MM cartridges offer very similar output levels (between 2.5mV and 5mV) and a friendly impedance for the vast majority of phono stages included in a wide range of integrated amplifiers and AVRs — the same can’t be said for MC cartridges or even MI (Moving Iron) from brands like Grado Labs.
The Grimm Audio PW1 is an example of a phono preamp that can handle any MM and MC cartridge types and output to almost any amplifier, stereo receiver, or AVR with the proper equalization, gain, boost, and other adjustments as needed.
On paper, the specs look impeccable, and the build quality is also excellent, but it does have a cumbersome bulky look that results in adding another large-sized component to your audio setup.
Also, do you really need to shell out almost $5,000 dollars for the PW1 when there are several lower-priced alternatives that may also incorporate MC and MM cartridge compatibility that will do just fine if you don’t need PW1’s precision setting options?
Price & Availability
The Grimm Audio PW1 Phono Preamp is available from Authorized Dealers for $4,900 (US) and €4,800 (EUR).
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