Best Guitar / Bass Synthesizers Under $500 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.

This little cable is a crucial link for Roland guitar synth users. It’s a no-frills, reliable way to connect your guitar’s GK pickup to a Roland synth like the VG-99 or GR55, letting you access those classic synth tones. Perfect for players already invested in the Roland ecosystem looking for a dependable connection.

The GKC-10 is a no-frills, essential cable for anyone using a GK-compatible guitar or bass with older Roland gear like a GR55 or VG99. It’s a solid, dependable link, especially valuable for players wanting to resurrect vintage setups or integrate them into modern rigs – just be sure your gear is compatible first.