Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Schematics and Layouts => Topic started by: Montywitha-Y on September 26, 2022, 04:53:59 PM

Title: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on September 26, 2022, 04:53:59 PM
I'd like to start by thanking you all for having me in your forum! I'm new to both solid state amps and to electronics builds. I am wondering if anyone here has a schematic or wiring diagram (makes noob blood boil just slightly less) for the foot switch that works with the Randall RG1003H amp head. It seems I'm deeply allergic to the idea of paying $100 for this foot switch (when they can even be found). If not, I would humbly ask if an owner of that foot switch could take a good picture of the layout and post it? Anything would help. Thanks, again!
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: joecool85 on September 26, 2022, 09:14:57 PM
Quote from: Montywitha-Y on September 26, 2022, 04:53:59 PMI'd like to start by thanking you all for having me in your forum! I'm new to both solid state amps and to electronics builds. I am wondering if anyone here has a schematic or wiring diagram (makes noob blood boil just slightly less) for the foot switch that works with the Randall RG1003H amp head. It seems I'm deeply allergic to the idea of paying $100 for this foot switch (when they can even be found). If not, I would humbly ask if an owner of that foot switch could take a good picture of the layout and post it? Anything would help. Thanks, again!

I haven't looked this one up, but most amps just simply short the tip and sleeve of a 1/4" cable for the switch.  To test this, plug in a guitar cable, and then use a wire (or other piece of metal) and short the tip and sleeve - see if it changes the channel on the amp - it probably will.  If so, you'll need to determine if it needs a momentary or standard switch.  If it switches channel when you connect the two leads, then changes back to the original channel when you disconnect, you need a standard switch.  If it stays switched until you touch the leads together again, you need a momentary switch.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on September 27, 2022, 12:46:31 AM
Thank you. I will test that as soon as I can. It is a 3 channel amp, so if there's any further technical info to make things work correctly to switch between the 3, I'd sure appreciate it. Like I said, I am new to these concepts and am looking for greater understanding. Thanks all!
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: joecool85 on September 27, 2022, 09:10:05 AM
I looked up the manual for this and found it is a two button switch on a TRS 1/4 cable.  This just means it uses a stereo 1/4" cable rather than standard mono guitar cable.  Testing will be the same way, but you will go from the ground at sleeve (ring closest to the wire) to the tip or to the middle ring.

https://www.randallamplifiers.com/wp-content/uploads/sites/9/2019/09/RG1003HMANUAL.pdf
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on September 28, 2022, 12:11:50 PM
Thanks Joecool85!!!
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on October 06, 2022, 01:40:03 PM
I hate to belabor this but I have built this foot switch to the best of my knowledge but button 1 switches between channels 1 and 2 just fine and button 2 does nothing, so I am unable to switch to channel 3. Any further suggestions would be amazing and appreciated. Also, again, if anyone has this switcher, I would deeply appreciate any interior photos of the layout. Thanks again!
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: g1 on October 06, 2022, 05:26:39 PM
joecool85 explained how to test whether you needed momentary or latching type switches.  What were the results of that test?
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on October 06, 2022, 06:10:53 PM
Results indicated the need for momentary switches. I built the box with momentary switches and got the result I mentioned above.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: joecool85 on October 06, 2022, 08:26:20 PM
Quote from: Montywitha-Y on October 06, 2022, 01:40:03 PMI hate to belabor this but I have built this foot switch to the best of my knowledge but button 1 switches between channels 1 and 2 just fine and button 2 does nothing, so I am unable to switch to channel 3. Any further suggestions would be amazing and appreciated. Also, again, if anyone has this switcher, I would deeply appreciate any interior photos of the layout. Thanks again!

First, I'm assuming you are using a TRS (stereo, three conductors) cable?  If not, that is the issue.  If so, you should be able to connect the ring and sleeve together for the second switch.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on October 07, 2022, 04:58:50 PM
Yes. I am using a TRS cable and stereo output jack. Would you mind clarifying your last sentence as if you were talking to a child😀?
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: phatt on October 07, 2022, 08:52:19 PM
I think Joe means you have a TRS  (Tip Ring Sleeve)

Short the Tip to the Ring gives you the 3rd possible connection which may trigger the 3rd option.
Phil.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Tassieviking on October 08, 2022, 03:47:42 AM
Like this
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: g1 on October 08, 2022, 12:23:15 PM
When you were doing the tests to see if you needed momentary or latching switch, how did you get it to engage channel 3 ?
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Montywitha-Y on October 08, 2022, 07:16:13 PM
Grounding out the very tip of the plug switched it to channel 3. Grounding the ring made it switch between 1 and 2.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: g1 on October 09, 2022, 03:12:48 PM
Quote from: Montywitha-Y on October 08, 2022, 07:16:13 PMGrounding out the very tip of the plug switched it to channel 3. Grounding the ring made it switch between 1 and 2.
Do you have an ohm-meter to check your work?
put one probe at the plug tip and one at the sleeve (ground)
When you push the switch it should read 0 ohms, when not pushing switch it should read 'OL' or similar.

If you don't have a meter, post some pictures of the wiring at the plug and switches.
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: Tassieviking on October 09, 2022, 11:46:09 PM
I was under the impression that was how it worked, one switch is for ch1 or ch2 and the other switch changed over to channel 3
Title: Re: Randall RF-1003 Footswitch for Randall RG1003H
Post by: joecool85 on October 11, 2022, 08:54:58 PM
Quote from: Tassieviking on October 09, 2022, 11:46:09 PMI was under the impression that was how it worked, one switch is for ch1 or ch2 and the other switch changed over to channel 3

That is correct according to the manual I found.