Preform channel-switching and effect in/out with one switch?

[JJRockford]

Is it possible to build a usual channel-switching box (for a 2-channel amp) which could switch effects in and out at the same time? That should be a combination of a channel switch and a bypass-box if you know how I mean?

[Seljer]

yep, its possible

for channel switching, most amps just have you connect the tip of the 1/4" plug to the sleeve with a momentary switch


on a 3DPT switch that leaves another 2 sections that you can use for a bypass loop (or 2 completely different selectable loops)

[Meanderthal]

 A 3pdt stompable momentary? Where can I get those?

[Pushtone]

There already is a looper on the market with this very feature.
The Tonebone Loopbone.
http://www.tonebone.com/tb-loopbone-using.htm

I've been wanting to do this too on a homebuilt looper but
to make it compatible with as many amps as possible it would
need the tip/ring and momentary/latching switches found in the Loopbone.





The Loopbone seems to cover all the bases with these switches.
The tip/ring switch is important on amps that have channel switching and reverb on/off with one TRS 1/4" jack.
The latching/momentary thing is also mandatory if one is to use a looper with many different amps.
My Vox AD30VT like a latching footswitch for channel switching while the Line6 Spider prefers a momentary.

[JJRockford]

Radial effects are pretty expensive. But it's still maybe worth the money, comparing to build one yourself? Or are there any similar schematics? Could do it without the midi-feature...

[Ben N]

I know this is more than you asked for, but worth the read just to get ideas--some kind of CMOS/relay system would work great for that, and RG Keen has a lot of stuff on his site that you can use as is, or simplify/modify for your needs.  Check it out.

http://www.geofex.com/Article_Folders/remoteftsw.pdf
http://www.geofex.com/FX_images/relays2.gif
http://www.geofex.com/Article_Folders/cd4053/cd4053.htm
http://www.geofex.com/Article_Folders/fxswitchr/fxswitchr.htm

Ben

[d95err]

for channel switching, most amps just have you connect the tip of the 1/4" plug to the sleeve with a momentary switch

On most amps I've seen it's a latching switch (unless the amp has lots of digital junk in it). This is easy to test, just plug in a regular 1/4" cable and see what happens when you short the tip-sleeve of the other end.

If the amp wants a latching switch, you can simply use a 3PDT switch and use one pole for the amp switching. If you want LED indication, you could use a millenium bypass, or use a non-true buffered bypass.

[Pushtone]

If the amp wants a latching switch, you can simply use a 3PDT switch and use one pole for the amp switching. If you want LED indication, you could use a millenium bypass, or use a non-true buffered bypass.

Perfect!

I would go with the input buffer to split the signal to the loop send jack and bypass with a 3PDT to yield an LED indicator.
You could put a second switch 1/4" jack in to give you a choice of buffered input and non-buffered input.
I drew it up. I added a polarity switch to select tip OR ring to be used with amps that have one TRS footswitch jack that does channel and reverb switching.

[d95err]

Different amps may have implemented the switching differently. I.e. in some amps, shorting tip and sleeve will mean "OFF" and on other amps "ON". Therefore, you may want a switch to change if the loop is connected when Tip-Sleeve is closed or when it's open.

You can implement this with an SPDT: (Hope this makes sense)

FS = Footswitch
PH = "phase" switch

Code Select Expand


      FS    PH
       /*---*\
Tip---*      *-----GND
        *---*


[Pushtone]

Yes,

I understand how that would be important for compatibility among amps.

I tried to add this feature to the drawing. This should work OK.
I called it a STATE toggle, as in what "state" the amp channel is in.
Also drew in the second un-buffered input using a switching jack for times when an booster
pedal is used in front, or when the looper is fed from a buffered output.

So the only thing not covered is the momentary vs latching thing.

I think amps that respond to momentary channel switch signals are rare.
I can't think of any. But it might be cool to start / stop a drum machine via footswitch.