In article , Trevor Wilson
wrote:

wrote in message
ups.com...
Hi

Does anyone know where I can source a good quality rotary switch (2
pole and 20 ways) to make a stepped attenuator??


**You'll certainly hear a difference, alright. 20 steps is utterly
inadequate to resolve the differences in level required for a decent
system. Try 100+ steps and you'll be getting somewhere.

20 steps, you have to be joking!

Oddly enough, I find that 21 steps suits me fine in use. Been using 21-step
attenuators for years, and find both the range of adjustment and the sizes
of the steps are no problem in practice.

Looks like there is a dramatic and unexpected distinction between 20 steps
and 21. :-)

Above said, I'll add two caveats.

1) The above is for domestic replay equipment. If I wanted to adjust levels
in the context of professional 'live' recordings then I'd agree that 20
steps would be insufficient. It would lack the required range and
resolution. But the point here is I find that the recording/broadcast
engineers have already set decent levels to the point where a 21 step seems
to me to cope fine.

2) I do tend to modify the input sensitivity and/or output levels of
sources to avoid the situation where I'm having to switch between a 2V
nominal source and a 150mV nominal one and having to wind the volume
setting up or down around 20dB just to correct for this. This is largely
because I tend to use a mix of 'old fashioned' and 'more modern' sources,
though.

Slainte,

Jim

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