424 Tape Preamp

The 424 Tape Preamp replicates the dry audio path of one channel of the Tascam 424 Portastudio Mk. I, a 4-track tape recorder from the late 1980s to the early 1990s. While 4-track recorders have a long history of being misused to create interesting drive and distortion effects, the 424 in particular is one of the foundational pieces of Mk.gee’s unique guitar tone.

The 424 Preamp has four knobs, each corresponding to a control on the original Tascam unit. The Input control is the equivalent of “Trim” on the Tascam, a potentiometer that cuts the input signal. It’s intended to prevent clipping, but can be used to intentionally overload the op-amp stages as a drive control.

This is followed by a standard 2-band Baxandall EQ which boosts or cuts frequencies by +/-10dB, centered at 100 Hz and 10 kHz. The volume control is equivalent to the channel’s “Master” slider. These are the only four controls that affect the audio signal; the slide switches only control the routing of the signal to the tape recorder or outboard effects.

The Demo Tape Fuzz by Mid-Fi Electronics (available as our Torus project) is a similar circuit that was also designed to sound like an overdriven tape recorder, and no doubt the Tascam was one of the inspirations for that circuit. But, the DTF is not based directly on any specific model as far as we know—so while it does capture the spirit and functionality, the 424 Preamp is actually an exact copy of what Mk.gee uses.