Oakley DN-34 BBD Upgrade Module for the KT DN-34 Analogue Time Processor

Replaces the expensive and rare SAD512D BBD array, making repairs to this wonderful device more cost effective.


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.


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 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.


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.


Prices

Click here for how to order.

DN34 BBD PCB issue 1 ...................................................... 35GBP Temporarily out of stock. More boards will be available in late June.

3207 BBDs are available to purchase from most online guitar effects parts shops. All other parts used in this project can be purchased from your usual electronic component supplier.

All prices include VAT at UK rates. Shipping and postage is additional to these prices. See also the FAQ page.

It is possible to use two Oakley Sound DN34 BBD boards to replace all sixteen SAD512D BBDs.


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Copyright: Tony Allgood
Last revised: June 06, 2017.