Sigma JM-SG45+


Get the ultimate typing experience with the Sigma JM-SG45+, a fully ergonomic mechanical keyboard designed to offer the best comfort and accuracy.



The Sigma JM-SG45+ acoustic guitar is a true work of art that any guitar player can appreciate. This guitar is part of the Sigma series, which is known for producing guitars that are high in quality and provide exceptional value for money.

From the moment you pick up the Sigma JM-SG45+, you will notice its sturdy build construction. This guitar is made from high-quality materials; the top is made of solid Sitka spruce, and the back and sides are made of Indian rosewood. This combination of woods results in a great balance of rich, deep tones and crystal-clear highs.

One of the most striking aspects of the Sigma JM-SG45+ is its intricate design. The guitar’s body is gorgeously finished, and the mother-of-pearl inlays on the fretboard add an extra touch of elegance. Additionally, the guitar’s binding is beautifully done, tying the guitar’s design together nicely.

The sound produced by the Sigma JM-SG45+ is nothing short of exceptional. The guitar has a full-bodied, balanced tone that is warm and textured. Its projection is also very impressive, with the sound ringing out clearly and loudly even when played softly.

The guitar’s neck is a slim profile providing a comfortable playing experience. This makes it easy to move up and down the fretboard, and it is perfect for both fingerpicking and strumming.

In conclusion, the Sigma JM-SG45+ acoustic guitar is an excellent choice for any guitar player looking for a top-quality instrument that provides excellent value for money. It is a well-crafted guitar with a beautiful design that produces a luxurious sound. Thanks to its quality build and great sound, this guitar can be played for years and will easily become a player’s go-to instrument.

Sigma JM-SG45+ properties

Product name JM-SG45+
Brand Sigma
Type String Instruments
String Instruments Acoustic Guitar
Number of Strings 6 pcs
String Type Steel
Built-in Microphone No
Handedness Right-handed
Number of Frets 20
Cutaway No Cutaway
Size Dreadnought
Pickguard Yes
Wood Type (front) Spruce
Wood Type (back) Mahogany
Wood Type (body sides) Mahogany
Wood Type (neck) Mahogany
Colour Fireburst/Colourburst

Additional information


Product type

String Instruments

Number of Strings

String Type

Built-in Microphone


Number of Frets




Wood Type-front

Wood Type-back

Wood Type-body sides

Wood Type-neck



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Frequently Asked Questions:

What is the recommended string gauge for the Sigma JM-SG45+ acoustic guitar and how can I change the strings properly?

The Sigma JM-SG45+ acoustic guitar comes with D'Addario EJ16 Phosphor Bronze Light (12-53) strings. These strings are suitable for most players and offer a warm, balanced tone. If you prefer a different gauge or type of string, you can always replace them according to your preference.

To change the strings on your Sigma JM-SG45+ guitar, follow these steps:

1. Prepare all necessary tools: You will need a new set of strings, a string winder (optional), a tuner, and a clean, flat surface.

2. Loosen the strings: Using a string winder or your fingers, gently loosen each string by turning the tuning key counterclockwise until they are slightly slackened.

3. Remove the old strings: Carefully pluck each string to remove tension before pulling them off the bridge and tuning pegs. If necessary, cut the excess length from the ball ends using a pair of wire cutters or scissors.

4. Install the new strings: Thread one end of the high E (thinnest) string through the hole at the bridge, then pass it under the corresponding tuning peg. Repeat this process for each string, making sure they are threaded in the correct order from high E to low E.

5. Stretch and tune: Once all the strings are installed, stretch each one by pressing down on the fretboard with your left hand while using a string winder or your right hand to tighten them. Continue this process for each string until they have reached their proper pitch. Use a tuner to ensure that each string is in tune with itself and with the other strings.

6. Repeat as needed: Depending on how often you play your guitar, it may be necessary to change the strings more frequently. As a general rule, most players should replace their strings every 2-3 months or after approximately 100 hours of playing time.

How does the X-bracing design of the Sigma JM-SG45+'s top plate contribute to its rich, full-bodied tone?

The X-bracing pattern used in the construction of the Sigma JM-SG45+'s top plate is designed to provide optimal stiffness and projection. The braces, which are crafted from spruce, are strategically placed in an "X" shape beneath the strings, allowing for a more efficient transfer of vibrations between the strings and the body. This results in a rich, full-bodied tone with excellent balance and clarity. Additionally, the X-bracing design helps to prevent the top plate from warping or cracking over time, ensuring the longevity and durability of the instrument. Overall, the X-bracing on the Sigma JM-SG45+'s top plate is a key factor in its exceptional tone and playability.

How does the unique combination of a solid spruce top and sapele back and sides on the Sigma JM-SG45+ contribute to its exceptional tonal qualities?

The use of a solid spruce top on the Sigma JM-SG45+ guitar is significant because spruce is known for producing bright, clear and resonant tones. The solid construction of this top ensures that the sound produced by the strings will be rich and full-bodied. The sapele back and sides complement the spruce top perfectly as they add warmth and depth to the overall tonal profile of the guitar. Sapele is a dense wood, which allows for a louder projection of the sound produced by the guitar. Together, the solid spruce top and sapele back and sides create a unique combination that results in exceptional tonal qualities for this guitar. The balance between the brightness of the spruce top and the warmth of the sapele back and sides creates a rich, complex tone that is both pleasing to the ear and satisfying to the player's touch. Overall, the Sigma JM-SG45+ guitar has been crafted with great attention to detail, ensuring that every note played on it is performed to the best of its ability.

How does the onboard electronics system of the Sigma JM-SG45+ contribute to its overall acoustic and electric playing versatility?

The onboard electronics system in the Sigma JM-SG45+ plays a significant role in enhancing the guitar's overall acoustic and electric playing versatility. The system includes an CT4B II preamp, which allows for easy volume and tone control when amplified. This feature enables the player to achieve a balanced and clear sound whether performing quietly or at high volumes. Additionally, the CT4B II provides a built-in tuner, making it convenient for players to quickly and accurately tune their guitar on the fly without the need for an external tuner. Overall, the onboard electronics system in the Sigma JM-SG45+ contributes significantly to its versatility as both an acoustic and electric instrument, allowing for a wide range of playing styles and applications.