The 8 Ball is a dual-octave pedal from Danish maker T-Rex, listed by the company under the name "8 Ball Dual-Octave"1. It sits in the wider family of octave and pitch pedals, and it is a compact unit: T-Rex gives its size, including knobs, as 100 x 55 x 120 mm (3.9 x 2.2 x 4.7 in, W x H x D) and its weight as 0.315 kg (11.1 oz) excluding battery and packaging1.
What sets the 8 Ball apart is the two-channel layout: each channel has its own dedicated knobs for the upper and lower octave signal, and an A/B switch lets you jump between two saved octave mixes without reaching down to turn knobs mid-song1.
Controls
| Control | What it does |
|---|---|
| On/Off | Turns the effect on and off |
| Mix | Blends the octave signal with your dry signal |
| Hi oct A / Hi oct B | Upper octave level for channel A and channel B |
| Lo oct A / Lo oct B | Lower octave level for channel A and channel B |
| A/B switch | Switches between the two saved mixes without turning knobs manually |
The two-channel arrangement is the point of the pedal: you can set one mix for a verse sound and another for a chorus, then change between them with the A/B switch. As T-Rex puts it, "The 8-Ball allows you to do this without having to reach down and turn the knobs manually"1.
Power and connections
The 8 Ball runs on 9 or 12 VDC through a 2.1mm barrel plug, center negative, and draws 130 mA at 9 VDC1. That draw is high for a single pedal, so a daisy chain shared with several pedals may not have enough current to spare for it. It also takes a 9V alkaline battery, but T-Rex lists battery life at only 1 to 3 hours, so battery power is a short-term option at best1.
With a 130 mA draw at 9 VDC1, the 8 Ball needs more current than many multi-output supplies deliver per jack. Give it its own output or a supply rated for the draw.
Connections are simple: an input jack, an output jack and a 9VDC jack1. T-Rex publishes a user manual as a PDF on its site1.
Inputs and what it tracks
T-Rex says the 8 Ball tracks most electronic signals, so it is not limited to guitar. The maker's own words: "It also works dandy on bass guitars, keys or even vocals"1. For bass players, that puts it in the same territory as other bass pedals that handle octave work.
On the technical side, the pedal's input impedance is 500K stereo, its output impedance is 1K Ohm, and the maximum input level is 5.5Vp-p1. Bypass is buffered rather than true bypass; T-Rex says the custom designed algorithm analog dry signal, with no digital conversion, and the buffered bypass keep your tone intact1.
Questions
Does the T-Rex 8 Ball take a battery?
Yes. T-Rex specifies a 9V alkaline battery, and the maker lists battery life at 1 to 3 hours. Because the pedal draws 130 mA at 9 VDC, a battery will not last long, so most players will want to run it from a power supply instead.
Is the 8 Ball true bypass?
No. The 8 Ball uses buffered bypass. T-Rex says the pedal keeps an analog dry signal with no digital conversion, and that the custom designed algorithm and buffered bypass keep your tone intact.
Does the 8 Ball work with bass or keyboards?
Yes. T-Rex says the 8 Ball tracks most electronic signals, including guitar, bass and keyboards, and that it also works on vocals. The maker's own words are that it works dandy on bass guitars, keys or even vocals.
What power supply does the 8 Ball need?
T-Rex specifies 9 or 12 VDC with a 2.1mm barrel plug, center negative. The pedal draws 130 mA at 9 VDC, which is more than many daisy-chain supplies can spare, so a supply with enough current per output is worth having.
How much current does the 8 Ball draw?
The maker lists current draw at 130 mA at 9 VDC. That is a heavier draw than most single pedals, so check what your power supply delivers per output before adding the 8 Ball to a shared chain.
Is the 8 Ball polyphonic?
Yes. T-Rex describes the 8 Ball as offering two channels of precise, fast tracking polyphonic octaves, meaning it can generate upper and lower octaves from full chords rather than single notes only.
Sources (1)
- → T-REX EFFECTS ← Pedals for guitar and bass players!, T-Rex Effects
