Dizengoff Audio D4 Mic Preamp
Dizengoff Audio D4 Mic Preamp
For Gear Heads:
The Dizengoff D4 Mic Preamp is a tribute to a rare and much loved British tube console from the 1960’s. The original circuit was designed by the Recording Engineering DevelopmentDepartment as a replacement for the Siemens V72S amp cards used in an earlier British console. It featured three gain settings (+36, +40, and +46), and a ‘fine trim’ knob that allowed the user to trim gain by a few dB. The D4 has expanded that range from +20 up to +60 using a 12 step rotary attenuator. Like the original design, the D4 ‘trim’ control allows the user to fine tune the gain by 2-4dB depending upon the gain switch setting.
The sound is huge and open – heard on albums recorded by The Beatles, Pink Floyd, and The Zombies between 1964 and 1968. It has incredible detail, and the kind of wonderful coloration that only an EF86 pentode can deliver. It’s often considered to be the sound of John Lennon’s “Revolution,” which used two console channels in series to achieve an overdriven sound.
Signal path transformers are custom wound right here in Chicago. They’re based on the transformers used in the original, but they take advantage of modern materials. The input transformer is a hi-nickel (80% nickel content) and the output transformer is a lo-nickel (50% nickel) for excellent fidelity.
The power supply is internal. It’s built around a Japanese Nippo Steel R-core power transformer. It has extremely high efficiency and low noise compared with traditional E-I core transformers and plays a significant part in achieving the D4’s low noise performance.
Beatles recorded through it. So did Pink Floyd and the Zombies. The Dizengoff D4 gives you that classic 1960s British tube console that characterized the recordings made in a “certain” London studio between 1964 and 1968. The Dizengoff Audio D4 mic preamp is a tribute to the EF86 pentode preamp circuit in that desk. Dizengoff is “Matt Newport”, who designs and manufactures affordable, handcrafted boutique gear based on classic circuits. They're based in Chicago — part of the windy city's surging artisanal scene. Dizengoff's tag line is "Home of the new Chicago sound." Although the roots of that sound, in the case of the D4, are half a century old and a continent away.
1960s British Rock Sound
Designed to replace the Siemens V72S amp cards in a previous console, the new console preamps defined the sound of '60s British rock 'n' roll. Rather than a being a slavish reissue, the D4 pays homage by nailing the huge, open sound of the original while introducing significant improvements to the gain structure; notably, a 12-step rotary attenuator with 20-60dB of gain on tap. An additional trim, a feature held over from the original, is interactive with the stepped main control and lets you fine tune gain by up to ±4dB. Using these two knobs, you can access a range of new tonal options, from warm, liquid cleans to the rich tube saturation characteristic of EF86-equipped gear. On a historical note: John Lennon's heavily overdriven guitar sound on "Revolution" was taken DI and driven hard through two console channels in series.
Vintage transformer design, modern materials for low noise and high efficiency
The transformers used in the D4 signal path are based on the ones in the original preamps, but they leverage modern materials (trying to obtain as many of those parts locally in the Chicago area). To optimize fidelity, a high-nickel design with 80% nickel content is used for the input transformer, and a low-nickel (50%) transformer is used for the output. The D4 also employs an internal power supply built around a Japanese Nippo Steel R-core power transformer, which exhibits very high efficiency and extremely low noise as compared with traditional E-I shell-type core transformers. This plays an important role in the D4's outstanding signal-to-noise ratio.