Oakley DN-34 BBD Upgrade Module for the KT DN-34 Analogue
Time Processor
Construction difficulty: The PCB is
easy to construct but the full modification is complex. An
oscilloscope is required for calibration.
A single DN34 BBD PCB can replace one
channel of the DN-34 saving the need for eight working SAD512D
chips.
The DN-34 Analogue Time Processor effect
was made by Klark Teknik™ in the late 1970s. It features
two channels of analogue delay each capable of creating a delay
from around 1mS to around 27mS. The delay time could be
controlled from a front panel pot, an internal LFO with sine,
triangle and square waveforms, and an external control voltage (CV).
The two delays could be operated in series to give one longer
delay or in parallel to create interesting effects such as
through zero flanging. What was particularly good about the DN-34
was the very good sound quality available from the unit. Most BBD
devices tend to be noisy and have limited bandwidth but the DN-34
excelled in both these areas.
Each delay channel was made from eight SAD512D
bucket brigade delay (BBD) chips. These devices are very
difficult to source today and when you can get them they can be
very expensive. This Oakley Sound module is designed to replace
one channel of the DN-34 which replaces eight of these ultra rare
SAD512D chips and their ancillary circuitry with near identical
performance. It is, of course, possible to use two of these
modules to replace both channels and saving the need for sixteen
SAD512D.
The Oakley Sound DN34 BBD module uses four
Panasonic MN3207 BBDs – although you can also use V3207 and BL3207
devices with equal success. High speed, high current, non
overlapping dual clock driver circuitry allows usage of the 3207
device up to clock frequencies of 1.3MHz.
The sound when using the replacement board
is almost identical to the original circuitry – the only small
difference is a slight loss of gain when the delay time is very
small. In practice this makes little difference, if any, to the
effect heard, even when using the device in self oscillating mode
or very resonant flanging.
Klark Teknik™ is a registered
trade mark and is the property of its owner. Oakley Sound Systems
are not affiliated with Klark Teknik™ and the use of their
trade mark in these documents in no way means that Klark Teknik™
have endorsed this product.
An original issue 1 DN34 BBD PCB. Issue 1.1
is similar in layout but the solder mask is green not blue.
The four layer PCB is 103mm x
120mm in size and is connected to the DN-34’s main PCB via a
series of interconnects. Two way 0.1″ headers allow screened
cable or just single core multistrand cable to make the three
audio, one control voltage and one clock connections. The main
board needs to be slightly modified. Several components need to
be removed from the board and one resistor needs to be replaced.
This can be all done without removing the main board from the
chassis if you are careful. The original ICs can simply be
removed by pulling them from their sockets. Novice builders are
recommended to unscrew the main board from the chassis to get at
the underside of the main board for easier desoldering and
soldering.
To calibrate the DN-34 and DN34
BBD an oscilloscope is required.
To replace the BBDs in both
channels of the DN-34 two of these replacement PCBs are required.
Prices
DN34 BDD issue 1.1 PCB
……………………….. 36GBP each
Most of the other parts should be able to
be purchased from you usual electronic component supplier. Please
see the Builder’s Guide for more details.
See the Oakley Sound ordering
page for ordering information, shipping charges and payment
methods.
All prices include VAT at UK rates.
Shipping/postage is additional to these prices. See also the FAQ page.
Project Downloads
DN34_BBD
issue 1 Builder’s and Installation Guide
DN-34 Service Manual
Original Service manual – no component values unfortunately.
Construction
Guide Our handy guide to building
Oakley DIY projects
Parts
Guide Our handy guide to buying
parts for Oakley DIY projects
Schematics are only available
to purchasers of the PCB and will be sent via e-mail when the
board(s) are shipped.
Klark Teknik™ is a
registered trade mark and is the property of its owner. Oakley
Sound Systems are not affiliated with Klark Teknik™ and the
use of their trade mark in these documents in no way means that
Klark Teknik™ have endorsed this product.
It is possible to use two Oakley Sound DN34
BBD boards to replace all sixteen SAD512D BBDs.
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