Q. How do I install this?

A. Simply remove the jack end cap by turning counter-clockwise and replace it with the Acousti-Lok strap lock adapter. Spin clockwise until the Acousti-Lok is snug tight. Like the picture on the front of the package, the strap button should be aimed upward or angled slightly back toward your body when the guitar is in playing position. If Acousti-Lok does not spin snug tight to the recommended position it’s ok to apply a little force to spin it further. If the jack feels too tight to spin without applying excessive force, it will be necessary to loosen and reposition the jack. To insure a successful installation, make sure the jack is tightened securely to the guitar before installing Acousti-Lok. Acousti-Lok was not designed to be used on recessed or flush mount jacks. See 3 step photo in photo gallery on main page for this item for more details.

Q. How do I tell if I have a Metric or Standard Output Jack?  

A. It's difficult for us to say definitively which size your guitar will take. Most manufacturers change systems over the years and have used both on their factory installs. There are also many guitars with an aftermarket pickup installed and if you purchased the guitar from a previous owner it'll take a little effort to figure it out. Here are some tips to help. 

1. Your existing jack end cap that unscrews will have either a flat top surface found on most standard jacks or a slightly rounded top surface found on most metric jacks

2. Contact the guitar manufacturer and ask them to give you output jack spec(standard or metric) or the brand. The two most popular output jack brands are SWITCHCRAFT® that uses a standard size jack and LR BAGGS® that uses a metric size jack

3. Use a micrometer to measure the Outside Diameter of the output jack with the jack end cap off. The standard jack measures approximately 9.3mm and the metric jack measures approximately 8.75mm. A noticeable difference when using a micrometer. 

4. If you or a friend have a guitar with a system that you know is a FISHMAN® or LR BAGGS® you can remove that cap and try to install it on the guitar in question. FISHMAN® threads match up with the Standard Acousti-Lok and LR BAGGS® threads match up with the Metric Acousti-Lok.

5. You can look inside the guitar with a flashlight and inspection mirror to see if there are and markings on an internal preamp or barrel jack cover. Many of these parts are branded.

6. MARTIN® Guitars tend to have a FISHMAN® system installed from the factory. The Standard thread Acousti-Lok is your best bet.

    GIBSON® has used both Metric and Standard jacks.

    BREEDLOVE® guitars tend to have LR BAGGS® pickups installed from the factory.

Q. Where should the Acousti-Lok strap button be pointing to be in the ideal position to avoid unwanted loosening?

A. For the Standard (MN270) and Metric (MN271) Strap Lock Adapters the Acousti-Lok must be snug tight on the output jack and strap button be pointed back to the player when in the playing position (See photo below). Depending on the size of your gut, the strap button should be pointing somewhere between the 9:00-11:00 position. If it is not, then you will need to reposition the output jack thread and try again. See our video on how to do this. Once you get Acousti-Lok set in the right position you should not have to adjust it again. The reason for this strap button positioning is to avoid unwanted loosening of Acousti-Lok.

Q. Will Acousti-Lok work on my acoustic bass, ukulele and other string instruments with this problem?

A. It will work if it has the output jack specification listed on the product page.  


Q. Will this work on recessed or flush mount jacks? 

A. No


Q. Will the end of my strap block the output jack?

A. The amount of extra material that goes beyond the strap pin opening on a guitar strap varies considerably. While this material may seem to partially block the output jack opening, it is flexible and can rest against or lay over the guitar cable with no issue. If you’re running into an issue with your strap you may be able to trim the end of the strap, depending on how it’s made. Also, consider using a right angle plug into your guitar if you’re not doing so already. That may allow a longer strap end to rest over the jack once it’s plugged in. Acousti-Lok was designed to be as stealth and unobtrusive as possible while serving its ultimate purpose, securing the strap to the guitar with strap locks. A longer or larger design may not fit into some guitar cases as well and would protrude further off the guitar.


Q. What Acousti-Lok would work for K&K SOUND® pickups?

A. K&K SOUND® Pure Mini and Pure Classic works with the Standard Acousti-Lok (MN270)

K&K SOUND® Universal Sound Board Pickup (Hot Spot, Big Shot, Big Twin, Twin Spot) works with the Metric Acousti-Lok (MN271)


Q. Which Acousti-Lok will work for the DIMARZIO® Black Angel Acoustic Soundhole Pickup?
A. They use a SWITCHCRAFT® output jack on this model so our MN270 Acousti-Lok for Standard output jacks will work. 


Q. What size allen key wrench is needed to tighten the strap button?

A. 7/64” 


Q. Will Acousti-Lok work with DUNLOP® Straps Locks?

A. It's easy to convert Acousti-Lok to be used with DUNLOP® strap locks, but you will need a shorter screw. Simply loosen the screw holding the Acousti-Lok strap button in place and replace it with the DUNLOP® strap button.

We use and recommend a socket head cap screw #6-32. Screw lengths needed are 1/4" long for FISHMAN® and LR BAGGS® style (MN270 & MN271) and 3/16" for the TAYLOR® 9v EXPRESSION SYSTEM® (MN272).

If you're handy you can file or grind down the original screw to the appropriate length. Please note the screw can not protrude beyond the surface of the underside at all or it will scratch your guitar.

For more details on how to convert the Acousti-Lok to work with DUNLOP® Strap Locks CLICK HERE for a tutorial video.


Q. Do I have to buy Schaller brand strap locks to be compatible with Acousti-Lok?

A. No. Acousti-Lok comes equipped with a Schaller “style” strap pin already installed. You can use Schaller brand strap locks, or one of the many copies of their original design that are readily available. Here are several options:

Grover Strap Locks


Available in four colors: Black - GP800B, Nickel - GP800N, Chrome  - GP800C, Gold - GP800G

Fender Strap Locks


Available in three colors: Black - Model #: 0990690006, Chrome - Model #: 0990690000, Gold - Model #: 0022043049

Note: “Fender ‘F’ Strap Locks” are a completely different design and not compatible.

Guitar Center’s Proline Brand Strap Locks


Available in three colors: Black - Item #1275860129318, Nickel - Item #1275860129329, Gold - Item #1275860129634

Framus & Warwick - S-Style Security Lock System


Available in five colors: Black - SP 30315 SB, Gold - SP 30316 SG, Chrome - SP 30318 SC, Satin Chrome - SP 30317 SS, Nickel - SP 30319 SN


TAYLOR®, MARTIN®, FISHMAN®, SWITCHCRAFT®, SCHALLER®, BREEDLOVE®, LR BAGGS®, GIBSON®, DUNLOP®, K&K SOUND®, DIMARZIO® and all other third party brand names are trademarks of their respective owners. Music Nomad LLC is not affiliated with those owners, nor claims ownership of those marks.