Ternion Discrete Drive

Description

The Ternion Discrete Drive is a Class A transistor overdrive and fuzz circuit. Texture and distortion are generated through 3 cascaded transistor gain stages (thus, "Ternion", meaning "set of three"). The all discrete design functions as a combined series and shunt feedback gain block fed by a common emitter, sort of like a very primitive op amp. This approach to analog design was more common during the transition from tubes to transistors in the early 1960's, and it feels and sounds like something from that era. Featuring a 3-band EQ and a wonderful ability to clean up the signal with guitar volume, the circuit is highly touch sensitive because transistors in this design have less distortion correction than ICs, so your attack and input signal level make more of a difference in the output. Input impedance is high enough you can stack drives before it, but I think it sounds best first in the signal chain with lots of guitar volume interaction. FUZZ mode is engaged by an extra foot switch and is configurable via a centre frequency toggle switch and a hard clipping toggle switch. These change the texture, tone, and sag, of the circuit. The fuzz tones are very unique and "brassy" with lots of mid range content, a hint of octave, and long lasting sustain due to the number of carefully balanced gain stages.

• GAIN

  Controls the gain level for both the DRIVE and FUZZ portions of the circuit. It goes from clean to light breakup to heavy drive at max settings. Gain increases with HPF set to lower frequencies. Beautiful transistor clean boosts are also accessible with GAIN around 30% rotation, MASTER at 75%, and HPF set to higher frequencies. If higher frequencies are selected with HPF, then the total perceived volume reduces too because there is less bandwidth to amplify.

• BASS

  Passive bass control goes from 15Hz to 175Hz for custom low-end tightening.

• TREBLE

  This is a passive low pass filter that sweeps down to ~500Hz at most extreme setting.

• MIDS

  Actively controls the depth of a broad musical notch filter centred at ~850Hz which creates space for mid range frequencies to be restored when FUZZ is enabled. Having a mild mid scoop like this is common to many famous amps.

• HPF

  Choose the clarity and default level of drive of the circuit. Lower frequency settings let in more bass and the tones are naturally darker and "gainier." Higher frequency settings result in lighter drive and even treble booster tones at the lightest setting. This control is very interactive with GAIN settings and FUZZ mode.

• FUZZ HPF

  Controls the frequency of the FUZZ section of the circuit. This section is designed to work with whatever amp and guitar you may have by offering various mid boost frequencies that compensate for whatever your rig is lacking. The lightest setting on this switch makes the FUZZ sound more like a dirty high gain drive. This switch also affects the sag of the circuit, with the heaviest setting resulting in the longest sag.

• FUZZ CLIP

  Controls the texture and compression of the FUZZ portion of the circuit. Higher headroom settings give more transients and bass in the fuzz tones. Lower headroom settings intensify the presence of even-order harmonics and increase sustain even more, with stronger hints of octave added.

Input Z: ~140K (DRIVE), ~70K (FUZZ)
Output Z: ~5K
Gain:~+30dB (at max settings)
Current Draw: ~17mA

True Bypass
Requires a centre negative 9V power supply
Dimensions: 4.7 in x 3.7 in x 1.34 in
(119 mm x 94 mm x 34 mm)
No battery option. If user wants to use a battery, they must buy an external adaptor.