Why choose the Ortofon SPU #1 S moving coil cartridge
The Ortofon SPU #1 S is a moving coil cartridge built on the design Ortofon introduced with the original SPU in 1958, and it carries the DNA of that cartridge into an accessible, lower-priced point in the current SPU range. Ortofon positions it as a solution for playing a wide span of stereo recordings, from early pressings through to modern and contemporary releases, and it serves as the stated entry point for buyers who are new to the SPU family rather than already familiar with its higher-specified variants.
What makes the SPU #1 S different from other entry-level moving coil cartridges?
The SPU #1 S is a moving coil design, which sets its electrical behaviour apart from moving magnet cartridges before any other specification comes into play. Its coil generates a comparatively low output voltage of 0.18 mV at 1 kHz, 5 cm/sec, a figure typical of moving coil cartridges and one that calls for a phono stage or step-up device with enough gain and a suitable load impedance to amplify the signal cleanly. The cartridge carries a 2 ohm internal DC resistance and asks for a recommended load impedance of 10 ohm, figures a buyer needs to check against their phono stage before purchase. Unlike a moving magnet cartridge, whose stylus assembly can usually be swapped by the owner, the SPU #1 S ties its diamond permanently into the moving coil generator, which shapes several of the ownership and installation decisions covered below.
Which turntables and tonearms will it work with?
The SPU #1 S is a cartridge with a dynamic lateral compliance of 10 µm/mN, which places it at the lower end of what Ortofon classes as moderate compliance (10 to 20 µm/mN). That compliance figure, combined with the cartridge's 28 g weight, determines which tonearms suit it. Ortofon pairs moderate compliance cartridges with moderate mass tonearms, those with an effective mass between 11 and 25 grams, such as the SME IV, SME V, SME VI, Triplanar or Graham, because this combination keeps the cartridge-tonearm resonance frequency within the 7 to 12 Hz range that Ortofon treats as optimal, with 10 Hz recommended. The resonance frequency itself follows from the formula F = 1000 : (2 × π × √(M × C)), where M is the combined mass of cartridge, headshell and tonearm, and C is the cartridge's compliance; a buyer can run this calculation against their own tonearm's effective mass before fitting an SPU #1 S, since a resonance frequency that falls outside 6.5 to 14 Hz makes the system questionable.
How do you mount and set up this cartridge?
The SPU #1 S is designed to deliver its stated performance only when the tonearm carrying it is adjusted parallel to the record surface and set to the recommended tracking force. Ortofon specifies a tracking force range of 3.0 to 5.0 g (30 to 50 mN), with 4.0 g (40 mN) as the recommended setting, and a tracking angle of 20°. Getting the arm level and the tracking force correct matters because the cartridge's tracking ability, rated at 60 µm at 315 Hz, depends on the stylus sitting in the groove at the geometry Ortofon engineered it for; a cartridge set outside these parameters won't track grooves as reliably, whatever its on-paper specification. Ongoing care is limited to removing dust from the stylus regularly with a stylus brush, guided forward towards the diamond tip, and periodically lifting the cartridge from the tonearm to clean its gold-plated contact points, along with the matching points inside the tonearm, using a small amount of propyl alcohol. This stops dust or sticky residue from causing a poor electrical connection between cartridge and arm.
Who should choose the SPU #1 S?
The SPU #1 S is aimed at listeners taking their first step into the SPU range rather than those upgrading within it, and Ortofon describes it as an all-rounder for that purpose. Because the stylus isn't part of a replaceable assembly on any SPU moving coil cartridge, an owner can't swap a worn diamond themselves the way they could on a moving magnet design; Ortofon instead offers a Special Repair Service through its webshop and authorised dealers to retip or rebuild the cartridge when needed. A buyer who wants a cartridge with a simple, owner-replaceable stylus for easy upgrades is better served by a moving magnet model, while a buyer who wants to commit to moving coil technology and is prepared to use Ortofon's repair route for stylus wear is the intended owner of the SPU #1 S. The cartridge is built solely for mounting on a tonearm and isn't intended for any other use.
How does the spherical stylus shape sound reproduction?
The SPU #1 S is fitted with a spherical stylus with an R 18 µm tip radius, the most basic of the diamond profiles in Ortofon's range, sitting alongside elliptical and fine line styli, and the more advanced line-contact shapes such as Shibata, Replicant 100 and Fritz Gyger 70. A finer, more advanced diamond cut increases the stylus's contact area with the groove wall, which lets it follow smaller details in the groove and track closer to the profile of the original cutting stylus; a spherical tip, by contrast, is the simplest and least costly shape to produce, which is part of what keeps the SPU #1 S at its price point within the range.
What are the housing and coil windings made from?
The SPU #1 S housing is built from ground wood and resin composite, a material Ortofon uses across grinded wood construction to give the cartridge body its shape and mass. Inside, the armature windings and terminal leads use High Purity Copper (OFC), a conductor chosen for its purity and low resistance, which keeps the 2 ohm internal DC resistance low and supports a clean electrical path from the coil to the tonearm wiring. The cartridge is finished in matte black and weighs 28 g, a figure that feeds directly into the tonearm mass calculation covered under compatibility.
Where does the SPU #1 S sit in Ortofon's SPU range?
The SPU #1 S is positioned at the entry level of Ortofon's SPU line, sharing its 2 ohm impedance, OFC coil wire, ground wood and resin composite body and 28 g weight with the SPU #1 E, its closest sibling, which differs mainly in using an elliptical rather than spherical stylus for more detailed reproduction and expansive imaging. Moving up the range, models such as the SPU Meister Silver G MKII, SPU Classic GE MKII and SPU Classic G MKII step up to nude elliptical styli and sit at a similar 2 to 3 ohm impedance, while the SPU Royal G MKII and SPU Synergy move to nude Ortofon Replicant 100 and nude elliptical diamonds respectively, with correspondingly tighter channel separation and frequency response tolerances. The SPU Mono models depart further, built specifically for mono records with higher output voltages and higher internal impedance; the SPU Mono CG 25 Di MKII and SPU Mono CG 65 Di MKII also step up to a heavier 35 g body, demanding a different class of tonearm, while the SPU Mono G MKII keeps the same 28 g weight as the SPU #1 S. For a buyer who isn't sure moving coil technology, and its fixed, non-replaceable stylus, is the right starting point, Ortofon's guidance is to consider a moving magnet cartridge instead, since those retain the option of a simple stylus swap; for a buyer who wants to begin exploring the SPU sound specifically, the SPU #1 S is the stated point of entry before stepping up to the elliptical-stylus SPU #1 E or further into the nude-stylus models above it.
