The Squire 86 is an EF86 based preamplifier that is designed to be used as a front-of-amp booster/tone enhancer, or as a preamplifier - for use with a power amplifier or as the heart of a direct rig when combined with a cabinet simulator.
The EF86 tube is a pentode vacuum tube that has been used in the preamp section of a relatively small number of amplifiers over the years (noteably in vintage Vox AC15s and very early AC30s). While they can sound great and have a substantially hotter output than the more common 12ax7 triode gain stage, they are notorious for being microphonic when used in the front end of guitar amps - especially in combos. However, with some care applied to the circuit design, the tendency to be very microphonic can be reduced enough to make them quite useable, even in a preamplifier guitar pedal.
When used as a preamp the Squire 86 has a full bodied and rich tone with plenty of output on tap, making it a great foundation for running other pedals in to. When pushed hard with another boost, OD or preamp, the Squire 86 breaks up gracefully, reponding with musical compression and overdrive. The simple but effective feature set also allow it to be used to push other ODs or an amp in to more breakup.
Note that the Squire 86 is a single stage preamp - as such it will not breakup of it's own accord, even as the Volume control is raised high. When used on it's own the Squire 86 is a clean preamp. In iorder for the preamp to breakup or produce an overdrive effect, it will have to be driven quite hard by another pedal with a strong output. While it is true that amps with an EF86 preamp are usually capable of significant overdrive, this is only as a result of the EF86 preamp driving the power amp into saturation itself. An exception would be if the amp has another front end tube that in turn can drive the EF86 into overdrive (not the case for a Vox AC15 for example, where the EF86 drives the power amp directly).
The Squire 86 runs off 9VDC (power supply provided), which is converted inside the pedal to around 250VDC, as well as 6VDC for the tube heater supply.
The Squire 86 has controls for:
Treble - a high end roll-off control, similar to a "Cut" control or "Tone" control found on many Vox amps;
Bass - a 3-way mini switch provides 3 levels of bass or overall fullness to the sound;
Volume - sets the output level;
Mode - this is a 3-way bright switch. In conjunction with the Treble control, a wide variety of dark to quite bright tones are available. The bright switch works in a similar manner to those on many guitar amps - at low Volume control settings the brightness effect is greater. The effect is reduced as the Volume control is raised;
Output level switch (on the back of the pedal) - provides three output levels to make the Squire 86 easy to dial in for FOA (front iof amp) use, preamp use into a power amp or effects return, or full output for driving a tube power amp hard into saturation.
Measurements: 3 7/8” wide x 4 ¾” deep x 2.56" tall
Power requirements: 9VDC @ 500mA, center negative, 2.1mm jack
Weight: 1.27 lbs (575g)