Fret-King Line Doctor review

Patch up your tone

  • £59
All Fret-King stompboxes have flexible dual input/output options

MusicRadar Verdict

A no-brainer for keeping your tone intact with long cable runs.


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    Saves your tone on long cable runs. Price. Connection options.


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The Fret-King Line Doctor, part of the firm's first stompbox range, has no sound of its own, but is designed to 'heal' your tone if it degrades - usually the consequence of using long cable runs and/or a series of 'true bypass' pedals.

"The Line Doctor does a great job at the front of our signal chain, delivering a significantly brighter signal"

Most manufacturers offer true bypass these days: the feature is seemingly a must-have for many purchasers, but a chain of them can suffer from signal degradation, notably a reduction in high frequencies due to issues that we don't have the space to discuss here.

The Line Doctor provides buffering to counteract that. In a test setup with four true bypass pedals and average cable lengths, the Line Doctor does a great job at the front of our signal chain, delivering a significantly brighter signal, but it could work at different points in a chain, not least your effects loop.

While its footswitch is, to a certain extent, superfluous (a buffer should be an always-on device) it usefully lets you A/B and hear the effect that the pedal is having. And that effect is all good!

Trevor Curwen has played guitar for several decades – he's also mimed it on the UK's Top of the Pops. Much of his working life, though, has been spent behind the mixing desk, during which time he has built up a solid collection of the guitars, amps and pedals needed to cover just about any studio session. He writes pedal reviews for Guitarist and has contributed to Total Guitar, MusicRadar and Future Music among others.