OTTA Theorbo Cartridge

The Mandolin's voice, more capable.

The Theorbo is OTTA's second cartridge and the natural progression from the Mandolin. Same designer, same German voicing, same body footprint and arm compatibility — but with three deliberate upgrades that move the cartridge from "remarkable at the price" to "competitive across price bands." The Theorbo is for the listener who has heard the OTTA voice and wants more of it: more resolution at the top, more grip on complex material, tighter channel work, and a stylus profile that lets all of that arrive intact.

Design notes

The first upgrade is the stylus. The Mandolin's refined elliptical is replaced with a Micro-Ridge profile — a fine-line cut that contacts a larger area of the modulated groove wall and retrieves high-frequency information an elliptical physically cannot. Micro-Ridge styli also reduce record wear over thousands of plays, because the contact pressure spreads across more groove surface.

The second upgrade is the coil. The cross-coil geometry of the Mandolin gives way to a square coil wound from 6N OCC wire in a denser, more symmetrical pattern. The result on the spec sheet is channel balance tightened from < 0.8 dB to < 0.02 dB at 1 kHz — an order-of-magnitude tightening — and channel separation that opens up another 2 dB. What that translates to in listening is a more locked-in stereo image and a wider dynamic envelope.

The third upgrade is bandwidth. The Theorbo extends from 15 Hz at the bottom (vs. 20 Hz on the Mandolin) to 30 kHz at the top (vs. 25 kHz). Tracking ability climbs from 75 µm to 80 µm at the standard 315 Hz / 2 g reference. Compliance ticks up marginally from 15 to 16 µm/mN — both cartridges sit comfortably in medium-mass-arm territory.

Everything else is shared with the Mandolin: ruby cantilever, samarium-cobalt motor with enlarged magnetic gap, gold-plated pure-iron yokes, black sandalwood body, aluminum motor frame, hand-winding by 25+ year technicians, individual quality control on a real tonearm.

How it sounds

The Theorbo is not a different cartridge from the Mandolin — it is the Mandolin's voice with more capacity. The midrange-first character is preserved; what changes is what arrives around it. Strings have more air, brass has more bite without becoming bright, complex orchestral material holds together at higher volumes, and the stereo stage is more precisely located in width and depth. For a listener whose system can resolve the difference — typically a phono stage above $5K and a speaker that images precisely — the Theorbo is the version of OTTA's voice that travels furthest.

Specs

• Type: Moving Coil (MC), stereo
• Output: 0.38 mV @ 3.54 cm/s
• Internal impedance: 8.6 Ω
• Recommended load: 100–470 Ω
• Dynamic compliance: 16 µm/mN
• Tracking force: 1.5–2.0 g (1.8 g recommended)
• Frequency response: 15 Hz – 30 kHz (±3 dB)
• Channel balance: < 0.02 dB @ 1 kHz
• Channel separation: > 28 dB @ 1 kHz
• Cantilever: Ruby
• Stylus: Micro-Ridge diamond
• Coil: Square, 6N OCC
• Body: Black sandalwood (CNC, aluminum motor frame)
• Weight: 8.4 g
• Recommended arm mass: Medium
• Break-in: 35 hours
• DL-103-compatible mounting

Pairing & setup

Medium-mass arm. 100–470 Ω loading window. ≥ 60 dB MC phono gain. The Micro-Ridge stylus is meaningfully more setup-sensitive than the Mandolin's elliptical — VTA, azimuth, and stylus rake angle all matter more, and the cartridge will reward a careful alignment with measurable image precision and air. 

Contact Alma to arrange a showroom appointment.