Ibanez Wiki

The Gotoh SG381 is a style of machine head (a.k.a. tuning peg) installed on a number of Ibanez guitar models. It is manufactured by the G-GOTOH Gut Co., Ltd. in Japan. The Gotoh SG38 is a predecessor model which is virtually indistinguishable.

The SG381 offers a 1:16 gear ratio. Versions are available for both inline and 3-on-a-side (L3+R3) headstock configurations. A variety of button shapes are also available, though most Ibanez guitars are equipped with style "07" which is an ovaloid shape with squared off sides (as shown in the black peg in the image above). It is available in locking and non-locking versions.

SG381 varieties[]

MG-T locking mechanism[]

The Gotoh MG-T (Magnum Lock-Trad) mechanism allows the user to lock the tuners once the instrument is in tune. It features a thumbscrew locking mechanism to stabilize tuning while playing and preventing incidental contact with the tuners from altering the instrument's tuning.

MG locking mechanism[]

The Gotoh MG (Magnum Lock) mechanism allows the user to lock the tuners once the instrument is in tune. Instead of a thumbscrew locking mechanism like the MG-T variety (see above) the Magnum Lock mechanism is engaged as the user twists the button to adjust the tuning.

Height adjustable locking posts (H.A.P-M)[]

The SG381 is available with height-adjustable posts (H.A.P). This allows the user to adjust individual strings to dial in the oscillation, which contributes to sustain. The H.A.P-M design combines the adjustable post height with the Magnum Lock system.

Ibanez models[]

These machine heads are used on a variety of Signature series, Prestige and Iron Label models. For an inventory of models using the SG381, see this list.

Similar tuning machines[]

Several other Gotoh tuners are used by Ibanez. Some acoustic models use the SG301 which is very similar to the SG381 except that the retention screw for the SG301 is located directly below the post rather than at a 45º angle from the post as with the SG381.

Gotoh makes an upscale line of tuning machines, their flagship "SG510 series", which are used on some Ibanez models. The SGS510, SGS510Z and the SGL510 are interchangeable with the SG381 in terms of installation; the SGS510 and SGS510Z have a slightly smaller body making them suitable for six-inline installations while the SGL510 can only be used in three-by-three configurations.

Ibanez also makes an in-house die-cast tuner that is visually similar to the SG381.


Additional images
Gotoh MG-T MagnumLock
Gotoh MG-T machine heads installed on an Ibanez RG headstock
Gotoh MG-T specs
Gotoh MG-T specifications (SD90)
Gotoh SG510 HAPM
Height Adjustable Post (HAP) description
Gotoh SG-Buttons-2016
SG series button shapes


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