Combo guitar amplifiers incorporate all components of an amplification chain in a single enclosure. They are different from other “stack” amplifiers in that they’re a self-contained unit designed for portability. You can find them in different sizes, configurations, and output levels to suit different needs. Combo amplifiers are popular for beginners and professionals players as well.

During the late 1920s to mid-1930s, small portable PA systems and guitar combo amplifiers were fairly similar. These early amps had a single volume control, one or two input jacks, field coil speakers, and thin wooden cabinets. Remarkably, they didn’t have tone controls or even an on-off switch. 

Guitar combo amplifiers were first used with bass guitars and electric pianos, but these instruments produce a wide frequency range and for several reasons need a full-range speaker system. For instance, much more amplifier power is required to reproduce low-frequency sound, especially at high volume.

Reproducing low frequencies also requires a suitable woofer or subwoofer speaker and enclosure, with bass cabinets that are often larger in size than a cabinet for mid-range or high-range sounds. The open-back cabinets used on many electric guitar amps, while effective for that instrument, do not have good bass reproduction.

While combo amplifiers offer many benefits, the fact that they have a limited amount of built-in speakers is considered a disadvantage. Having a larger number of speakers makes amplifiers more suitable for wider sound coverage in larger performance venues. However, in recent times, many combo amplifiers have started to allow for the attachment of additional speakers.

Types of combo guitar amplifiers

The three main types of combo guitar amplifiers include:

Tube combo amps: They were used on the first guitar amplifiers and are still popular today. Tube combo amps come in numerous types and they are generally more expensive than solid-state guitar amps. They are known for their distinct sound but need to be maintained regularly, and the glass tubes need replacement eventually, which can be quite expensive. 

Solid-State combo amps: They’re an alternative to tube combo amps and are more cost-effective. You can find them often in smaller practice and studio combos. Unlike the above-mentioned tube guitar amps, they don’t require maintenance so often. We know them for their reliable performance and “cleaner” sound at higher volumes, especially when compared to their tube counterparts

Modeling combo amps: They integrate circuitry from tube, solid-state, and hybrid combo amps with digital processors which can emulate the sounds of different amplifiers and effects. They offer numerous preset or the possibility to design custom sounds based on the modeling algorithms. This technology was once very expensive but is now available on many entry-level combo amps.