[sdiy] Socket schematic symbol question

cheater cheater cheater00 at gmail.com
Thu Oct 28 18:22:23 CEST 2010

you could use the right one for a TRS insert. Bear in mind Tom's recommendation.
You'd use the left one to ground the output OR input when it's not
being used: from what I understand you can use this to control the
total impedance seen by output from a single source to multiple
(unbuffered) outputs. I think you can also use it to make the
unbuffered inputs to a single mixing bus behave better, but I have no
idea how anymore. I remember some sort of mention. I'm probably wrong
on that count, but maybe some creative mind here can come up with a
way to do this.

You can also use the right one (shorted switch on ring) with mono
inputs/outputs: ring is usually grounded, which means that the
"switch" pin is either ground or floating. You can use that in your
logic, for example to switch a mixer channel into the mixing bus... I
think it would be easy to convert it to a voltage which is +5V when
there is a plug inserted and 0v when the plug is not inserted, e.g.
for controlling relays.

> That's often done using a normal stereo jack with no 'break' or 'make'
> connections at all. Instead when a normal mono jack is inserted into
> a stereo socket, the ground and the ring are connected together by
> the jack. When there's no jack, the circuit has no ground connection
> and is switched off.

How does that work? I'm sorry, I'm having a bit of a hard time visualizing :-)


On Thu, Oct 28, 2010 at 17:55, Ben Lincoln <blincoln at eventualdecline.com> wrote:
> Would you see something like either of these designs used in the TRS
> connectors for the inserts on a mixing board, or would those have break
> connections on more than one of the pins?
> Alternately, are one or both how (some?) guitar pedal manufacturers wire up
> the input jack so that the pedal is powered off when nothing is connected? I
> would think those would use mono connectors, but maybe some manufacturers
> use stereo jacks for some reason?
> On 2010-10-28 08:22, Donald Tillman wrote:
>> The left one is a stereo jack with a closed (shorted) switch on the tip
>> connection.  The right one is also a stereo jack, but with the closed switch
>> on the ring.
>> Neither is what I'd consider 'standard'.
>>   -- Don
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

More information about the Synth-diy mailing list