Dual C 939 specifications

Category : Autoreverse cassette decks

Brand : Dual

General

connectors

Tech nical data

special features

manufacturer: Dual
model: C 939
type: single
year of construction: 1977 – 1979
Made in Germany
colors: silver, brown, Black
remote control: no
power consumption: about 35 watts
dimensions: 440 x 105 x 300 mm (WxHxD)
weight: 7 kg
factory price approx.: 1'050 DM

number of inputs: 3
- microphone (2 jacks) 0.3 mV/10kOhm
- Line in (DIN socket) 0.45 mV/4.7 kOhm
- Line in (RCA Jacks) 70mV/82kOhm
number of outputs: 3
- Line out (DIN socket) 0-700mV/1.8 kOhm
- Line out (RCA Jacks) 0-700mV/1.8 kOhm
- headphones (mini-Jack) 4-2000Ohm

microphone (2 jacks) 0.3 mV/10kOhm
Line in (DIN socket) 0.45 mV/4.7 kOhm
Line in (RCA Jacks) 70mV/82kOhm

Line out (DIN socket) 0-700mV/1.8 kOhm
Line out (RCA Jacks) 0-700mV/1.8 kOhm
headphone (Jack) 4-2000Ohm

heads: 3
motors: 1
flutter:
band types: CrO2, FeCr, Normal
frequency response: Normal volume 20-14000Hz, CrO2-tape, 20-16000Hz, FeCr-Band 20-17000Hz
total harmonic distortion: 1,0-1,8 % (330Hz, 0db)
Auto-Reverse: Yes
title search: no
Dolby: B, FM
MPX-Filter : no
Fader: no
Pitch-control: no
CD Synchro recording: no

headphone output, adjustable
MIC input, Mono/Stereo
Continuous Play
Fade Edit (subsequent Deletion of passages during playback)
tape counter with Memory function
Limiter for recording level

verse for More models from the same series:
Dual C 919
Dual C 919-1 model with no author, no Fade Edit with VU-pointer instruments instead of LED chains
Dual C 939

image: Dual C 939

extract from the prospectus: Dual C 939

Test in "Hifi-stereo" 9 / 1977

The Dual C 939 cassette Deck is a further development of the Dual C-919, the VU-Meter LED chain have been replaced.
This device had Dolby-B and Dolby-FM circuits. The latter was used for FM / FM radio broadcasts to suppress noise and to tolerate the treble off again when Dolby-B noise reduction was used for recording.
By means of an optokopler control system, where strobe-like flashes normally signaled the correct tape running, if a malfunction or tape end came to a standstill or slowed down, the STOP process was initiated by tightening a magnet, which then triggered the mechanical buttons.
A so-called fade-edit circuit was also installed, with which one could then subsequently make targeted fades at the end of the tape to round off the abrupt cancellation of the music - even with backband control! For this purpose, the extinguishing head was used via a rotary controller, which regulated the signal strength of the premagnetization frequency, in order to variably extinguish the tape. The success could then be listened to immediately via the sound head!
Another feature of the Dual C 939 was the autoreverse facility.
With a little trick it was even possible to turn the machine into a continuous recording machine, for which purpose the switch-off mechanism at the end of the tape again only switched the tape running direction and just again the tape was overplayed - and just then the last minutes were stored depending on the maximum tape length.
On the right side of the device there was a built-in mixer for two microphones (2x stereo, or 1x mono, with automatic switching) and an audio input.
This tape deck was undoubtedly one of the better ones from the late seventies and early eighties, especially since - after it was removed from the manufacturer's program - it was sold out in batches as a leftover item, practically at half price. Better tape decks from the Far East were MUCH MORE expensive at that time, but top loaders were just out of fashion...
Today, the C939 actually only has nostalgia value, because there are a lot of sound and technically much better decks on the used market.