Solid State Versus Tube Rectifiers

A rectifier is an electrical device within a tube amplifier that converts alternating current (AC) to direct current (DC), in a process known as rectification. The rectifier is not in the signal chain portion of the amp so your guitar signal doesn't pass through the rectifier. However, the type of rectifier your amp uses does contribute to your overall sound and tone.

A tube based rectifier reacts differently than a solid state diode. When heavily loaded, a tube rectifier will produce what has commonly been called "sag" or "compression". One of the characteristics of this response is that the amp begins to produce a compressed overdriven sound with added volume. In the 60's with the rise of higher volume artists like Dick Dale and others, some players began to demand more tonal headroom and low-end definition. In response Fender began using silicon based solid state rectifiers in their new higher output amps like the Showman, Vibrasonic and others. These silicon rectifiers were just a fraction of the cost of their tube counterparts and they helped meet the evolving demands of guitarists.

While the solid state rectifier did help to create more clean headroom and a more articulate low-end response, many players still sought after the signature, compressed, overdriven tones found in the old Fender Champs, Tweed Deluxes and a number of vintage Gibson Amps. Up until the 60's, electric blues, jazz and early rock & roll was played through these amps which had a big effect on the tonal character of the music. Many felt that tube rectifiers were better suited for blues based styles because of the touch sensitive dynamics which yielded more to a player's attack. Many also felt they sounded warmer and less harsh and served up compression and sustain in a much different way than their solid state brother.

While the debate rages on the choice is ultimately a subjective one, and this article was just meant to point out some of the more general characteristics found in both types of amps.