DN701 — Extended-Memory Digital Delay Line

The DN701 extends the DN700 architecture with substantially greater delay memory: one input feeds three independently adjustable outputs, with delay time on each output adjustable from zero to 1.73 seconds in 26.5 microsecond steps. The signal-path topology — FDNR seven-pole elliptical filters and a differential voltage- and current-balanced input — is shared with the DN700, preserving the noise and distortion figures that made the series the broadcast standard of its period.

Delay Architecture

The 1.73 second per-output delay range supports applications well beyond simple speaker time-alignment, including programme delay for broadcast censorship, large-venue back-delay-tower work and creative slapback effects on tracking dates. The 26.5 µs resolution keeps positional artefact below audibility for all practical use.

Signal Path

Audio input is differential, voltage- and current-balanced to achieve symmetry better than -50 dB from 20 Hz to 10 kHz. Seven-pole elliptical input and output filters use FDNR (Frequency Dependent Negative Resistance) circuitry for optimum noise and distortion. Dynamic range is better than 85 dB unweighted, better than 90 dB A-weighted at any delay setting. Memory settings are retained for one year minimum without power.

Application

Broadcast programme delay, large-venue PA delay-tower alignment, vintage studio production. The DN701 is the extended-range sibling to the DN700 and shares its sonic signature.

Specification Highlights

• One input, three independently adjustable outputs
• Delay 0 to 1.73 seconds in 26.5 µs steps per output
• FDNR seven-pole elliptical input/output filters
• Dynamic range >85 dB unweighted, >90 dB A-weighted
• Differential voltage- and current-balanced input
• Memory retention >1 year without power
• 1U rackmount