|Elliott Sound Products||Rotary Switch Extension Shaft|
When you build a preamp (either active or passive), it is always best if the selector switch (and often the volume pot as well) is at the back of the case next to the input sockets. This keeps internal wiring to a minimum, and thus reduces capacitance and loss of high frequencies. The trouble is, rotary switches only have a 50mm shaft at best, and this is nowhere near long enough.
The extension shaft will allow you to have the selector knob at the front, and the switch at the back where it belongs. These shafts are incredibly hard to get, but I have the ES250 in stock at all times. The shaft is very rigid, so will not cause the switch to have a "spongy" feel. Despite the order code, the ES250 is actually 220mm long. It has been shortened slightly to make it easier to fit into a standard post bag, and to reduce cost. Had I kept it the original length, the cost would have increased quite significantly (material costs plus extra postage costs).
The shaft comes with a panel mounting bush, and suits standard 6.35mm (1/4") shafts as found on nearly all switches and pots. It can be shortened down to as little as 40mm (internal dimension) by cutting off the excess with a hacksaw and filing the end. Smaller (i.e. less than 40mm) units can be made to special order if desired.
... And this is what it looks like (typical)
Made from aluminium, and supplied with screws and tapped holes to attach to the switch shaft, and a panel mounting bush (may be steel or brass)
The only standard length is 220mm, and these are available as a stock item. Any other length can be made to order (typical lead time is 1 week), and will be more expensive. If you need lengths other than 220mm, shorter shafts can be made by simply cutting off the end (minimum total length is about 40mm). If you need a longer shaft, please e-mail me to discuss.
|Size (mm)||6.25 (shaft dia) x 220 long (including sleeve)|