Ibanez Portamento SRF705 5 String Fretless

Ibanez Portamento SRF705 5 String Fretless

Quite simply the most popular 5 string fretless that we sell....and for good reason. 

The Ibanez Bass Workshop Portamento SRF705 is a purpose-built fretless that bridges the expressive world of the upright bass with the power and versatility of a modern electric. This is a bass designed to be its own thing and to deliver great tonal versatility in combination with incredibly slick playability. 

At the heart of the SRF705 is a 5-piece Maple/Bubinga through-neck construction, joined seamlessly to mahogany body wings for exceptional low-end warmth and long, singing sustain. The neck-through design is immediately apparent in how notes bloom and hold, giving lines a fluid, vocal quality that fretted basses simply can't replicate.

The extended 30 note Panga Panga fingerboard opens up territory normally reserved for upright players in thumb position, with the full upper register available and surprisingly easy to navigate. Side-line markings and dot inlays keep you oriented without cluttering the clean face of the board — a subtle guide for your ears to lean on when need be.

Tonally, the SRF705 is genuinely versatile in a way that surprises players. The dual Bartolini MK1 humbucking pickups with active 2-band EQ deliver everything from a warm, round Jaco-style voice to a full-bodied P-bass tone, and they sit particularly well in the fretless context where their warmth and smoothness shine. Alongside the magnetic pickups, Ibanez's exclusive AeroSilk Piezo Bridge System — built with specially designed saddles — adds a remarkably convincing upright-like acoustic character to the mix. Players describe the piezo sound as silky, deep, and organic, working beautifully with flatwound strings to push the upright simulation even further.

The control layout puts a full suite of tone-shaping at your fingertips: Master volume, pickup balance, and bass/treble controls govern the Bartolini side of things, while a dedicated Master volume and tone control handle the AeroSilk piezo independently. On the rear of the body, individual piezo volume adjusters for each string allow you to fine-tune string-to-string balance for a perfectly even acoustic response — a thoughtful detail that sets this system apart from generic piezo implementations.

Light, well-balanced, and comfortable for long sessions, the SRF705 earns consistent praise from players across styles — jazz, rock, ambient, and everything in between. It's the kind of bass that makes you rethink what an electric bass can sound like.