HumminGuru S-DUO Pro

HumminGuru S-DUO Pro: ultrasonic cleaning and integrated weighing

A clean stylus makes an audible difference. Residue accumulated on the stylus tip, embedded dust, or groove deposits gradually degrade sound quality and accelerate record wear. The S-DUO Pro combines two essential functions for turntable maintenance in one compact unit: an ultrasonic stylus cleaner and a digital scale for setting vertical tracking force (VTF). The Pro version succeeds the original S-DUO with several improvements, including a rechargeable battery and a storage base for accessories.

Contact-free cleaning at 110 kHz

The ultrasonic technology used here stands apart from traditional methods. Where vibrating brushes create mechanical contact with the diamond, the S-DUO Pro uses 110 kHz waves to generate microscopic cavitation bubbles in the water bath. These bubbles implode and lift away dirt without touching the diamond surface or stressing the cantilever.

This frequency was not chosen at random. HumminGuru calibrated it to deliver enough energy to dislodge stubborn deposits while remaining below the threshold likely to damage the adhesive of bonded diamonds or the delicate structures of cantilevers. The cycle lasts 20 seconds and starts with a simple press. Three to four drops of distilled water are enough, or about 0.3 ml.

Supports suited to each cartridge

The bottom of the tank holds a rubber ring on which the cartridge body rests during cleaning. Three diameters are provided to fit different cartridge geometries. The principle: the cartridge body must rest on the ring, while the stylus tip is immersed in the water without the cantilever touching the support. HumminGuru publishes on its website a regularly updated compatibility list (Audio-Technica VM520EB, Denon DL-103, Ortofon 2M Red, Hana ML, Nagaoka MP-110, among others).

This list obviously does not cover every cartridge on the market. “Nude” models without a body, such as some high-end Lyra or Dynavector cartridges, require more caution. If in doubt, it is best to contact the cartridge manufacturer to verify compatibility with liquid cleaning.

The integrated scale: measuring VTF after cleaning

Precise tracking force adjustment protects both records and the cartridge. The S-DUO Pro includes a digital scale with a non-magnetic aluminum platform, which avoids interference with the powerful magnets of MC and MM cartridges. The LCD screen automatically adjusts its orientation according to the device position: after cleaning, simply turn it over to switch to weighing mode.

The stated accuracy is 0.01 g, with a recalibration function using the included 5 g weight. Tare is performed automatically at startup or with a simple touch on the dedicated icon.

One point deserves attention: the weighing platform sits about 6 mm above the level of a record on the turntable platter. With a tonearm whose height is adjustable (VTA), it is possible to compensate for this difference. On some fixed arms, such as those from Rega, the measurement may be slightly affected. Indirect measurement techniques exist to work around this constraint.

What the Pro version adds

The original S-DUO ran on four AAA batteries. The problem: ultrasonic cleaning quickly consumes energy, and several users had reported frequent replacements. The Pro version includes a 1050 mAh rechargeable USB-C battery, capable of providing more than 100 cleaning cycles before needing a recharge.

The charging base also serves as storage for the three rubber supports, drying pads, and dropper pipette. All accessories stay grouped together, which reduces the risk of misplacing these small parts.

Technical specifications

Ultrasonic cleaning

• Non-contact ultrasonic cleaning technology
  • Cleaning frequency: 110 kHz
  • Micro-bubble cavitation to remove dust, grime, and hardened dirt from the stylus tip
  • Frequency optimized to ensure effective cleaning with no risk of damage to the diamond or the cantilever
• Alcohol-free cleaning
• Cleaning cycle duration: 20 seconds
• Amount of water required: 3 to 4 drops (0.3 ml)
• Compatible with all cartridges on the market
  • Audio Technica VM520EB, AT95E, Denon DL-103, Ortofon 2M Red, Hana ML, Nagaoka MP-110, among others

Precision scale

• Aluminum weighing platform
• Precision: 0.01 g (two decimal places)
• Bidirectional LCD screen
  • Reversible display depending on the position and use of the device
• Automatic zero reset on power-up
• Manual zero reset by touching the gauge icon
• Calibration available
• Measurement of vertical tracking force (VTF) directly after ultrasonic cleaning

Power supply

• Built-in rechargeable battery
  • Capacity: 1050 mAh
• Input: 5 V DC, 0.8 A via USB-C
• Power: 5 W
• Charging via charging dock or USB-C cable

Dimensions and weight

• Dimensions: 13 x 7.86 x 5.2 cm
• Weight: 128 g
• Compact, lightweight, and portable format

Accessories and storage

• Charging dock with built-in storage for accessories
• Package contents:
  • HumminGuru S-DUO Pro
  • Cleaning cover
  • Charging dock
  • USB-C charging cable
  • 0.5 ml water pipette
  • 5 g calibration weight
  • Rubber supports for stylus tip (x3)
  • Drying pads (x2)
  • User manual

Key features

• 2-in-1 design: ultrasonic cleaning and precision scale
• Touch controls
• High compatibility with phono cartridges on the market

General information

• Product name: HumminGuru S-DUO Pro
• Model: HG010
• Color: black