Gotoh SG381 MGT Locking Tuning Keys — 3 a Side, 07 Button, XL Posts, Black (SG381MGT-X-BLACK)

The Gotoh SG381 MGT (SG381MGT-X-BLACK) is a set of six locking tuning keys in a 3-a-side (3L, 3R) configuration with Gotoh 07 style buttons, XL long posts and pure black finish. Built in Japan to Gotoh's precision engineering standards, the SG381 MGT features a 16:1 gear ratio, traditional thumbwheel Magnum Lock mechanism, non-staggered uniform 21.5mm posts accommodating headstock thickness up to 17mm, and a 10mm shaft hole requirement. Includes screw-in bushings, washers and fixing screws. The SG381 MGT is the 07 button variant in Gotoh's MGT locking range — the same thumbwheel locking mechanism and XL post specification as the SG301 MGT, with a contemporary rounded 07 button in place of the classic oval 01 button and a 16:1 gear ratio in place of the SG301's 18:1. For players on 3-a-side instruments with 10mm bushing holes who want a modern button aesthetic with traditional locking performance, the SG381 MGT is the natural choice. Before ordering, verify your headstock's existing bushing hole diameter (must be 10mm) and confirm base plate dimensions against the technical diagram provided.

SG381 MGT vs SG301 MGT — Key Differences

Gotoh 07 Button — Contemporary Profile

The Gotoh 07 button is a rounded, contemporary tuner button with a different visual character from the classic oval 01 button used on the SG301 MGT. Where the 01 button closely replicates the Rotomatic profile that Gibson players recognise from decades of production instruments, the 07 button presents a modern aesthetic — a clean rounded form that suits contemporary instrument builds and modifications without referencing a specific vintage format.

For players replacing tuners on a modern production instrument, building a new guitar, or modifying an instrument away from a traditional aesthetic, the 07 button is the appropriate choice. For players specifically replacing Grover 102 Rotomatics on a Les Paul or SG who want the headstock to look unchanged, the SG301 MGT's 01 button is the closer visual match.

MGT Thumbwheel Locking — How It Works

The MGT (Magnum Lock Traditional) mechanism operates identically across both the SG381 and SG301 ranges — the button style and gear ratio are different, the locking system is the same. Wind the string onto the post normally, tune to pitch, then tighten the thumbwheel on the back of each tuner to lock the string in position. The locking mechanism is entirely on the back of the tuner and invisible from the front of the headstock. No change to stringing technique is required and strings do not need to be cut short.

The practical result of thumbwheel locking is that the string cannot slip at the post regardless of playing intensity, tremolo use, or string bending — eliminating post-slip as a source of detuning and significantly improving tuning stability across a full performance.

16:1 Gear Ratio — Precision Tuning Performance

The SG381 MGT's 16:1 ratio — sixteen rotations of the button per full post rotation — provides finer tuning increments and better stability under string tension than the 14:1 and 15:1 ratios on standard non-locking tuners. The improvement over stock tuners is immediately noticeable in use — finer pitch control per button turn and greater resistance to string tension moving the tuner out of position.

The SG301 MGT's 18:1 ratio is slightly higher — providing marginally finer increments per button turn. For most players in most playing contexts, the practical difference between 16:1 and 18:1 is minimal. The button style is the more significant distinction between the two models.

XL Long Posts — Uniform 21.5mm Height

The SG381 MGT's XL posts are a uniform 21.5mm height from base to centre of the string hole — all six posts are the same height. On a 3-a-side headstock, where strings travel approximately equal distances from each side of the headstock to the nut, uniform post height is the correct and standard specification.

The XL length accommodates headstock thicknesses up to 17mm maximum — covering the full range of Les Paul, SG and ES-series headstock profiles, including heavily lacquered and bound instruments where standard-length posts can be insufficient for correct tuner seating.

Finish Selection — Black, Chrome and Gold

The SG381 MGT is available in pure black (this product), chrome (SG381MGT-X-CHROME) and gold (SG381MGT-X-GOLD). All three finishes carry identical specifications — button style, locking mechanism, ratio, post length and included hardware are the same across all three. Select the finish that matches your instrument's existing hardware:

• Pure Black (SG381MGT-X-BLACK): Instruments with black hardware specification throughout
• Chrome (SG381MGT-X-CHROME): Instruments with chrome or nickel hardware
• Gold (SG381MGT-X-GOLD): Instruments with gold hardware — Les Paul Standard, Custom and Traditional with gold bridge and tailpiece

Who Is the Gotoh SG381 MGT (SG381MGT-X-BLACK) For?

• Guitarists with 3-a-side headstocks and black hardware wanting locking tuner performance with a contemporary 07 button aesthetic
• Players on modern production instruments with black hardware where a contemporary rounded button suits the instrument better than the classic oval Rotomatic profile
• Builders and luthiers fitting black locking tuners to new builds with 3-a-side headstocks and 10mm bushing holes
• Players who want the MGT thumbwheel locking system with the 07 button rather than the SG301's 01 button
• Players upgrading from stock non-locking tuners who want improved tuning stability and a modern aesthetic
• Players with chrome hardware should choose SG381MGT-X-CHROME — players with gold hardware should choose SG381MGT-X-GOLD

Specifications

Expert Advice and Installation at Angkor Music

At Angkor Music Melbourne we stock both the SG381 MGT and SG301 MGT ranges across black, chrome and gold finishes. If you are deciding between the 07 and 01 button styles and want to see both before committing, contact us. Professional installation is available through our guitar technician.

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