Klark Teknik DN34

Two discrete delay sections, a 70:1 sweep, and a noise floor that made studio engineers reach for it before the digital boxes arrived.

Overview

The DN34 Analogue Time Processor has two discrete, independently controllable delay sections. Two delay lines that can be swept and modulated separately open up effects a single-section unit can't reach. Klark Teknik's own advertising leaned hard on that point and called the DN34 an "exceptionally versatile signal processing and special effects unit." That's marketing copy, not a verdict, but the architecture is real. The two-section layout is what makes the more unusual effects on the DN34's list possible.

Klark Teknik published three numbers for the DN34, and they were the ones engineers cared about. Dynamic range is quoted as better than 90dB. In an analogue delay line, that separates a unit you can leave patched across a mix bus from one that adds audible hiss the moment it's engaged. Time sweep range is specified at 70:1, which is unusually wide for an analogue design and underpins the flanging and pitch effects the DN34 was sold on. Total harmonic distortion is quoted at less than 0.3%. All three figures - 90dB, 70:1, and 0.3% THD - appear in the DN34's own advertising. They're the reason the unit carried a reputation for clean, noiseless processing, unlike the gritty, noisy cheaper analogue delays of the period.

The DN34's effects list is long. Positive flanging. Negative flanging. Resonant flanging. Crossover flanging. Double tracking and triple tracking. Pitch detune and pitch shifting. True vibrato. Chorus. Loudness enhancement. A "cardboard tube" echo. Doppler and Leslie effects. Time-related frequency synthesis. Complex Doppler effects. Some of those are standard delay-line tricks. Others, like crossover flanging and time-related frequency synthesis, need two delay sections you can control separately and mix against each other. Klark Teknik also pointed to "full on-board mixing and phase reversal facilities" as exclusive features. Phase reversal is what gets you negative flanging as well as positive, and on-board mixing means you don't burn console channels just to blend the dry signal back in.

Studio-Sound (October 1979, p.104) noted that Klark Teknik had built a reputation for manufacturing the ultimate in signal processing products. The company's advertising for the DN34 leaned on that broader reputation as much as on the unit. The same campaign also pushed the DN27 and DN22 graphic equalisers. The copy made the pitch explicit: Klark Teknik products were assembled and checked by engineers rather than on a production line, and each unit went through alignment, a burn-in period, and final performance verification using a music source before it shipped. That's a manufacturer claim and should be read as one. It does explain how the DN34 was priced and positioned, and why it turned up in rooms where the budget existed to care about the difference.

The studio equipment lists of the period show where the DN34 landed. Rockstar Studio in London, a 24-track facility with an Allen & Heath Syncon console and a 3M M-79 multitrack, kept a DN34 in its sideboard rack alongside a MICMIX Master Room spring reverb, Rebis noise gates, and an Itam 3.77 tape deck used for repeat echo. At Eddie Offord's studios, engineer Chuck Allen listed the DN34 among the effects chain and described it in print as "real high-quality." That's a short verdict, but he had Eventide phasers and flangers and a rack of LA-2A tube limiters next to it for comparison.

The DN34 sits in a specific moment in Klark Teknik's line. The company's own advertising placed it alongside the DN36 analogue time processor and the DN70 digital time processor — the DN34 as the flagship analogue delay, the DN70 as the digital alternative arriving to challenge it. That's the context that makes the DN34 interesting in retrospect: it's an analogue design pushed about as far as analogue delay could reasonably go, sold into studios at the same moment digital was starting to make its case. The 70:1 sweep and the 90dB dynamic range are the sound of a technology being squeezed for everything it had left.