Best Guitar / Bass Synthesizers for Intermediate 2026

The KEY9 is a pedal that turns your guitar or keyboard signal into electric piano and organ style tones. It has nine presets, such as Wurli, Suitcase and Vibes, plus knobs to blend your original tone with the keys sound. It suits you if you want to add keyboard textures to your guitar or keys playing.

This is a slim pickup that adds synth capability to your electric bass. It works with four, five and six string basses and uses the Serial GK interface, so you will need a compatible Boss cable, which is sold separately. If you already use Boss guitar synth gear and want to play synth sounds from your bass, this is a good fit for you.

You get nine mellotron-style sounds, from strings and flute to choirs and brass, all made from your guitar, bass or keyboard. The effect and dry volume knobs let you mix in your clean sound, and the separate dry output keeps your untouched signal available. It suits you if you want orchestral or vintage tape textures without special pickups.

• Strings6-string

You get a GK pickup for 4-, 5- and 6-string basses, with a housing that is 30% smaller than the GK2B and a larger volume knob. The magnet spacing adjusts to match your bass's string spacing, from jazz-bass to six-string width. If you play bass and want a pickup that fits many different instruments, this one is a solid choice for you.

You would use this box if you want a GK pickup system to control a 13-pin device such as the SY-1000 or GP-10. It takes the Serial GK signal from a GK-5, GK-5B or GM-800 and turns it into the analogue 13-pin signal those units need. It also has an instrument input, so your regular guitar or bass pickup sound can pass through to the 13-pin output.

• Strings6-string

The Triple Play Express is a clever entry point into guitar-based MIDI synthesis. It’s fantastic for guitarists curious about exploring virtual instruments without complex modifications or a huge investment, especially those wanting a straightforward, portable setup. While it's not a replacement for a full-blown MIDI keyboard rig, it’s a surprisingly capable tool for sketching out ideas and creating unique sounds.

Okay, so you've got a vintage Roland guitar or bass with those classic 13-pin GK pickups, but you’re wanting to use it with newer BOSS synth pedals? This little box is your bridge. It’s a clever and surprisingly well-built solution for getting that legacy GK signal into a modern digital workflow – essential for serious synth bass players.

• Strings12-string

This processor gives you a lot of sound options for guitar and bass. You can switch to custom or alternate tunings quickly, and you can blend a guitar and a bass into one sound. It suits you if you want to explore new sounds and you have a GK-5 or GK-5B pickup ready to connect.

The DOD Meatbox is a fun, focused pedal for adding serious low-end rumble to your guitar or bass. It's a reissue, so it nails that classic, gritty synth bass vibe, but don't expect a ton of tonal flexibility. Perfect for metal, industrial, or anyone wanting a quick dose of sub-bass mayhem.