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General => Open Discussion => Topic started by: danwelsh on November 06, 2014, 03:46:25 PM

Title: footswitch for 4 input amp?
Post by: danwelsh on November 06, 2014, 03:46:25 PM
Hi guys, anyone know how a guy would build a footswitch for  4 input amp. What I mean is the jtm45 has 4 inputs and the classic setup is to put a patch cord from input 1 to input 2......I want to build a footswitch that will select between input 1 and 2 and both as they all sound different.  Anyone know how to tackle this?
Title: Re: footswitch for 4 input amp?
Post by: jkokura on November 06, 2014, 03:49:25 PM
A simple A/B/Y switch would do it. You'd have to run two cables from the board to the amp, but essentially an ABY switch gives you the options of:
- Input 1
- Input 2
- Both Inputs

Jacob
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 06, 2014, 03:54:16 PM
Quote from: jkokura on November 06, 2014, 03:49:25 PM
A simple A/B/Y switch would do it. You'd have to run two cables from the board to the amp, but essentially an ABY switch gives you the options of:
- Input 1
- Input 2
- Both Inputs

Jacob

Well that's cool.....would I need 3 foots witches? Or would a simple rotary knob do the trick?
Title: Re: footswitch for 4 input amp?
Post by: jkokura on November 06, 2014, 03:57:19 PM
No, an ABY switch is usually just two footswitches. One selects both/AB, and the AB switch chooses A or B.

Here's a common example: http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher (http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher)

Jacob
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 06, 2014, 04:08:41 PM
Quote from: jkokura on November 06, 2014, 03:57:19 PM
No, an ABY switch is usually just two footswitches. One selects both/AB, and the AB switch chooses A or B.

Here's a common example: http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher (http://www.musiciansfriend.com/amplifiers-effects/morley-aby-channel-switcher)

Jacob

Got it......thanks Jacob :)
Title: Re: footswitch for 4 input amp?
Post by: davent on November 06, 2014, 05:19:37 PM
There's this if you're wanting  diy.

http://www.generalguitargadgets.com/pdf/ggg_amp_aby.pdf
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 06, 2014, 08:41:34 PM
This will work won't it?
Title: Re: footswitch for 4 input amp?
Post by: jkokura on November 06, 2014, 09:05:43 PM
Yup, either will work,

The big difference is that the GGG option allows the user completely isolated outputs via the Transformers. I don't think thats really necessary in this instance.

Jacob
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 06, 2014, 09:13:47 PM
Okay. Thanks for the input Jacob :)......this will be done in approximately 2 hours lol
Title: Re: footswitch for 4 input amp?
Post by: salty on November 06, 2014, 09:46:55 PM
I was looking at this and I am a bit confused. I see that an ABY is going to let him send his guitar to input A or input B or both at the same time....but when I think of jumpering channels on an amp, I am not sure the ABY gets that done. What I think he would need is a switch that would let him plug his guitar into it and then in one position send the signal to a single input on the amp, in another send it to the other position on the amp and then in the third, create a bridge between the two unused inputs on the amp....Am I misunderstanding this? When you jumper the channels, you plug into say input 1 on one channel and then input 2 of that same channel would be patched over to input one of the second channel.  So I would think an AB switch could let him choose between input 1 on channel one or input 2 on channel two and a second switch would bridge the gap between channel 1 input 2 and channel 2 input 1. This would require 4 cables to the amp. Am I jsut really missing the solution?
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 02:53:24 AM
I built this one from here http://www.generalguitargadgets.com/effects-projects/boostersrouters/aby-switch-box/
Title: Re: footswitch for 4 input amp?
Post by: mgwhit on November 07, 2014, 03:41:51 AM
And how did it work?
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 03:57:22 AM
Quote from: mgwhit on November 07, 2014, 03:41:51 AM
And how did it work?

That's the funny thing......can't try it until the morning. Everyone went to bed.
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 04:10:53 AM
Looks good though I think.....
Title: Re: footswitch for 4 input amp?
Post by: mgwhit on November 07, 2014, 04:23:12 AM
Quote from: danwelsh on November 07, 2014, 03:57:22 AM
That's the funny thing......can't try it until the morning. Everyone went to bed.

;)  Oh well.  Looks great, though!
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 04:27:56 AM
I'm pretty confident it will work.....the leds light as they should when the footswitches are pressed.  I'll be sure to post soon as I try it.
Title: Re: footswitch for 4 input amp?
Post by: cooder on November 07, 2014, 06:46:48 AM
Looking good. I just wonder if you get some hum as the input that not engaged is not grounded by the looks of that schematic....
Let us know how it works.
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 03:53:22 PM
Well it works.....not as expected though....there is no hum which is good but when switching channels and I don't have the both engaged only input two works but when I engage the right footswitch I get switching from both...I'm confused now.
Title: Re: footswitch for 4 input amp?
Post by: salty on November 07, 2014, 04:09:43 PM
I guess I am glad that everyone ignored my question...I was in bed last night and started thinking about it and see what I was missing...it kind of works exactly as patching, but with one exception right? When you patch you are coming from either the bright or normal input on one channel into either the bright or normal inputs on the other channel. Would that make the tone different than using a Y to plug straight into an single input on both channels?
Title: Re: footswitch for 4 input amp?
Post by: danwelsh on November 07, 2014, 07:57:34 PM
Quote from: salty on November 07, 2014, 04:09:43 PM
I guess I am glad that everyone ignored my question...I was in bed last night and started thinking about it and see what I was missing...it kind of works exactly as patching, but with one exception right? When you patch you are coming from either the bright or normal input on one channel into either the bright or normal inputs on the other channel. Would that make the tone different than using a Y to plug straight into an single input on both channels?

Yeah. ....but I don't want to have to unplug/plug to switch