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The Telefunken TDA-1 (mono unit) and TDA-2 (dual unit) are new active FET direct box designs that utilize top quality components in a modern take on classic circuitry to give you a full, rich character that both complements and retains the natural tone and feel of your instrument. The TDA circuit employs discrete Class-A FET circuitry coupled with a high quality transformer that provides the perfect balance between clean, high headroom performance and warm, saturated tone with vibe.

Sonic Characteristic

While some direct boxes focus on providing sterile, ultra-clean gain, they often leave the instrument devoid of any soul or character. Conversely, some DI’s artificially hype too much low-end and overemphasize harmonic distortion, resulting in a tubby and undefined output. The Telefunken active DI avoids these common design pitfalls and delivers a new standard in reliability and performance for direct boxes.

Circuit Design

The heart of the design is a custom-wound output transformer by OEP/Carnhill, made in the UK. The circuit board features gold plated traces and is entirely hand-assembled with through-hole components, providing more secure and reliable connections than typical surface mount circuitry. The frequency response of the circuit is ± 2dB from 20 Hz to 70 kHz, with extremely low distortion and self-noise. Each individual unit is manually tuned by hand for the lowest distortion figure possible. High input impedance prevents the loading down of passive pickups. This careful attention to detail and high quality component choices results in a direct box with a harmonically rich low end and a detailed, open high-end clarity.


The circuit is housed in an extremely durable extruded aluminum enclosure with recessed switches and connectors. This rugged construction is virtually indestructible, able to easily withstand the wear and tear of gigging. Each channel features two heavy duty metal toggle switches to engage a -15 dB pad and ground lift. The circuit is powered from standard +48V phantom power with an LED indicating when it is powered. The TDA-2 unit features two independent DI channels with separate controls, giving you the ability to run two instruments through one footprint on stage or in the studio.

Key Features

• Custom-wound OEP/Carnhill transformer, made in the UK

• Rugged aluminum construction

• Class-A discrete FET circuitry

• Recessed switches and connectors for protection

• +48V phantom powered with LED indicator

• -15 dB pad switch

• Ground lift switch

• 100% through-hole components

• Amphenol connectors

• WIMA, Nichicon, and Panasonic capacitors

• 1% 1/4W metal film resistors

• 3-year warranty

Technical Specifications

Type: Active Direct Box

Frequency Range: 20 Hz - 50 kHz, ±1 dB

Power Source: +48V Phantom Power

Transformer: Custom-Wound OEP/Carnhill

Input Impedance: > 30 kΩ

Output Impedance: < 250 Ω

Maximum SPL (for 1% THD): +3.5 dBV (no pad); +18 dBV (with pad)

Input Connections: 1/4" Jack (per channel)

Output Connections: XLR Output, 1/4" Thru (per channel)

Dimensions: 100 mm L x 100 mm W x 50 mm H

Weight: 540 g

Included Accessories: Cloth Drawstring Bag

Telefunken DI TDA-2 Telefunken DI TDA-2
Telefunken TDA-2 Telefunken TDA-2
TELEFUNKEN Direct Box Series TELEFUNKEN Direct Box Series