Rozz R-5 Flanger repair

So I got an old Rozz R-5 Flanger on the workbench. It is in a no working condition. The outputjack was missing, the circuitboard is missing at least one diode and a transistor and some of the offboard wiring is loose. Seems like someone has tried to fix it but given up.

Rozz FL-5 Flanger

Did some search on the net but could not find a schematic for it but it seems identical to the Ampeg A-5 Flanger .

Ampeg A-5 Flanger

Searching on a schematic for the Ampeg Flanger did get me a schematic that seems correct.

The missing transistor was a 2SK30 for muting the Flanger effect, missing diode was connected to the gate of that transistor.So I got the offboard wiring reconnected and a replaced the missing components and fired it up. It just pass unmodulated signal. Measured the clock IC MN3101 with oscilloscope and found it did not send any clock frequency. Replaced it just to find that the BBD chip, a MN3006 was also broken. Replaced the BBD circuit and yes! There’s a flanging effect.

/Krister

 

BBD delay

Circuitbaords populated for a UKII.

The small circuitboard will hold the BBD circuits, in this case three V3205:s,  with trimmers for bias and output balance.

The big one holds the rest,  clocks, filters, LFO etc.

BBD Delay
Unicorn MKII