AEA TDI DUO is a two-channel active DI box powered by 48 V phantom power, designed by Fred Forssell. Built around a discrete Class A JFET stage and a Lehle step-down transformer, it delivers transparent, uncolored signal conversion — from passive guitar and piezo-equipped acoustics to synthesizers and drum machines.
10 MΩ Input and Passive Source Integrity
Passive pickups suffer high-frequency rolloff when loaded by a low-impedance input. The TDI DUO presents 10 MΩ per channel, giving passive transducers the correct load and preserving their full tonal character. For piezo-equipped acoustic-electrics, this eliminates the brittle, nasal quality common with budget interfaces. The JFET buffers the signal ahead of the transformer, keeping noise and THD at the floor even across long cable runs. The result is a DI that gets out of the way of the instrument.
Stereo Routing, Wet/Dry Tracking and Rack Integration
Two fully independent channels, each with a parallel THRU jack, allow simultaneous feeds to an amp and a console — the standard configuration for recording with a re-amp option. Stereo instruments (synths, stereo pedalboards) use both channels for a true L/R split without phase summation. The –20 dB pad per channel handles speaker-level signals and line-level sources from samplers or drum machines without any external attenuator. Per-channel ground lift resolves grounding loops independently, which matters when one channel feeds a FOH console and the other a stage monitor chain. Three TDI DUO units mount into a single 1U rack space using standard 19-inch adapters — giving you a six-channel DI station with a minimal footprint.
KEY FEATURES
- Two independent channels with individual THRU jacks (paralleled to input)
- Discrete Class A JFET stage + Lehle step-down transformer per channel
- Input impedance: 10 MΩ (instrument) / 55 kΩ (pad engaged)
- –20 dB pad per channel — handles speaker-level and active instrument signals
- Ground lift switch per channel
- Power: 48 V phantom power via XLR output
- Steel chassis with rack-mount screw holes — 3 units fit in 1U
- Circuit design: Fred Forssell; made in the USA
TECHNICAL SPECIFICATIONS
- Channels: 2
- Type: active DI, phantom-powered
- Input impedance: 10 MΩ (instrument) / 55 kΩ (–20 dB pad)
- Pad: –20 dB (switchable, per channel)
- Ground lift: yes (per channel)
- Input connectors: 2 × 1/4" jack (INPUT + THRU per channel)
- Output connectors: 2 × XLR (balanced)
- Power: 48 V phantom power
- Dimensions: 129 × 76 × 51 mm
- Weight: 0.8 kg
- Made in: USA
