Handmade Effects - Est. 2006

BFX Direct "Wolfbox" D.I. #002


This custom direct box is based on the original design by Ed Wolfrum, inventor of the passive DI in the early sixties. His design was used on countless Motown recordings and dubbed the “Wolfbox”.

The original "Wolfbox" used a Triad A11-J transformer. These are impossible to find and if you do, they will cost you a small fortune. After some research, I was able to identify similar vintage transformers (UTC 0-1 and 0-2) from the same era that provide almost the exact same frequency response and turns ratio.

The characteristic of the vintage UTC is clarity, flat frequency response, with a slight softness to the high frequencies and nicely controlled low end. Great for recording bass, guitar and keys.

The toggle switch on the top selects between "D" direct, no attenuation and "A" that when engaged, cuts 25dB of gain and then another 15dB when the level knob is rolled to zero, for a total of 40dB gain reduction. This is very handy for hot signals and when re-amping or sending an amplifier speaker output to the direct box. The balanced XLR output has a ground lift to isolate your signal from noisy ground loops. Two TS jack instrument inputs wired in series so you can send a copy of your instrument signal to an amplifier while you record direct. All components are premium quality and built to handle any stage or studio.

- Vintage UTC 0-1 transformer
- Vintage 0-17 magnetic shields with 25dB of noise rejection
- LMB Heeger chassis box
- Tocos RV24 Series, 24mm military-style potentiometer
- Switchcraft balanced XLR and unbalanced TS jacks
- Carling toggle switches
- Vishay BC 2-watt metal film resistors
- 22 AWG stranded and top coated hookup wire
- RCA style level knob
- Ohmite 0-100 dial plate