SIGMA 40 Acoustic Guitar OOO 4/4 Full-Size - Solid Spruce Tone

In this review of the SIGMA 40 Acoustic Guitar the bottom line is clear: this is a full-size OOO acoustic that suits both advancing beginners and budget-minded experienced players who want a warm, vintage-leaning tone without a high price. The handcrafted construction with a solid spruce top and sapele back and sides gives it a tonal depth and responsiveness that stands out for the category, while the included D'Addario EXP16 steel strings make it ready to play right away.

Key Features

• Solid spruce top: Provides an open, warm sound with strong mids and bass that improves with playing over time.
• Sapele back and sides: Offer a balanced, vintage-style resonance that supports the spruce top for a rich overall tone.
• OOO body shape: Delivers focused projection and comfortable playability for fingerpicking and light strumming.
• Rosewood fingerboard and bridge: Enhance sustain and feel under the fingers for smoother chord transitions and articulation.
• D'Addario EXP16 strings included: The guitar arrives strung and tuned with long-lasting steel strings to minimize initial setup time.
• Solid tuners and natural gloss finish: Keep tuning stable and present an attractive, vintage-tinted look that wears well.

Who It's For

The SIGMA 40 is aimed at students moving beyond a starter instrument, home players who want a more resonant, handcrafted instrument, and gigging acoustic players seeking a reliable second guitar. Its 4/4 full-size OOO body and slightly shortened scale make fretting comfortable for most hands while preserving full low end.

Players who need a fitted electric-acoustic setup, advanced stage professionals seeking boutique-level appointments, or those requiring ornate appointments should look elsewhere; this model focuses on tone, build quality, and playability rather than electronics or high-end cosmetic flourishes.

Pros & Cons

Pros

• All-solid spruce top and sapele back produce a warm, full-bodied tone with good projection.
• Handcrafted construction and rosewood fingerboard give a pleasing feel and solid playability out of the box.
• Includes D'Addario EXP16 strings and solid tuners, so the guitar is ready to play with stable tuning.
• Attractive vintage-tinted gloss finish that masks wear and looks refined on stage or at home.

Cons

• OOO body offers less belly than a dreadnought, so players seeking maximum volume and bass may prefer a larger body.
• No onboard electronics are included, limiting use for amplified performance without additional equipment.

Specifications

Our Verdict

The SIGMA 40 Acoustic Guitar is a well-built, great-value full-size OOO that excels for students and players wanting a warm, vintage-style acoustic without premium pricing. With a solid spruce top, sapele back and included D'Addario strings it offers reliable playability and a pleasing tone, making it an excellent choice as a main instrument for practice and small gigs.

Frequently Asked Questions

Does it come ready to play?
Yes, it ships with D'Addario EXP16 steel strings installed and solid tuners for stable tuning.

What body size is this and how does it sound?
The guitar is a 4/4 full-size OOO body that yields a focused, warm tone with strong mids and good projection for its class.

Are the top and sides solid wood?
The top is solid spruce and the back and sides are sapele (eastern mahogany), which together deliver richer resonance than laminated tops.