[sdiy] Dry/Wet effect relay that makes 'click' noise on changes...

[rsdio at audiobanshee.com]

Rather than a fairly complicated and expensive circuit like a sweepable filter, why not just fades from full volume to mute? That's surely been done. It's pretty much what the FET mute circuits are doing.

The trouble with either a sweepable filter or a fade is that we're talking about bypass, not mute, so the output still needs to pass the original signal. That means an active mixer stage, so that muting the effect does not also mute the input. The point is that folks sometimes want to avoid an active stage in their signal path when bypassed - especially when the battery dies!

Brian


On Jan 11, 2016, at 2:03 AM, Mattias Rickardsson <mr at analogue.org> wrote:
> Hmm, I'm thinking that signal-switching clicks are caused by frequency
> components being stopped or started faster than their periods. DC or
> bass frequencies can't be started or stopped very quickly without
> introducing clicks in higher frequencies, but treble signals can be
> switched much quicker since they just contain higher frequencies.
> 
> How about switching in signals by means of a filter that somehow
> sweeps from fully closed to fully open by fading in the higher
> frequencies quicker than the lower ones? I guess it would mean some
> kind of swept highpass-ish filter when switching a signal on, and a
> lowpass-ish filter when switching a signal off. Or a multiband
> solution fading in/out different frequency ranges with different
> attack times.
> 
> Probably not a new or revolutionary idea. So, has anything similar
> been done in any small clever circuit construction that minimizes the
> clicks for a particular application? It would be nice if it could be
> made more or less around the ordinary stompbox switches or Boss FETs.
> :-)
> 
> /mr
> 
> On 10 January 2016 at 22:05, Simon Brouwer <simon.o at brousant.nl> wrote:
>> Gordon,
>> 
>> Sorry, you are right. I was thinking about clicks occurring when no signal
>> is present, but I had not considered that that will often not be the
>> scenario when operating an effect bypass switch.
>> 
>>> Op 10 januari 2016 om 16:02 schreef Tom Wiltshire <tom at electricdruid.net>:
>>> On 10 Jan 2016, at 14:19, Simon Brouwer <simon.o at brousant.nl> wrote:
>>>>> If you're using mechanical switching, it's going to click no matter
>>>>> what you do.
>>>> 
>>>> Even with a mechanical switch that clicks very loudly itself, no click
>>>> need be present in the electronic signal if the circuit is designed and
>>>> implemented correctly.
>>> 
>>> Ok, now you've got me curious! How?
>>> 
>>> My experience has been closer to Gordon's, that contact bounce in
>>> mechanical switches causes clicks more-or-less whatever you do.
>>> 
>>> The current fashion for "True bypass" has always amused me somewhat, as
>>> when I was younger "Noiseless switching" was the big deal, and the Boss
>>> pedals with their bistable-controlling-FETs scheme were thought the height
>>> of sophistication!
>>> 
>>> Thanks,
>>> Tom
>