Can you guy help me with building and wiring the 4 way footswitch.
Recently acquired some old Hamstead Eclipe 20 prototype amp without footswitch.
Tried to contact Hamstead support but no luck, this is some old model and they don't have any info for that footswitch.
Footswitch jack on the amp is just mono Cliff jack with only 2 wires, plus ground wire.
On the hot end of the jack I'm measuring 15V.
I'm assuming that switching is made with some voltage differences which will trigger some specific switching circuit.
Is there a way to find out what voltages will trigger different switch?
Help with 4 way footswitch
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Help with 4 way footswitch
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Stevem
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- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Help with 4 way footswitch
What do you mean by “ 4 way “
What are the 4 things you want to control with the foot switch?
That cliff jack in your photo is only what’s called a tip sleeve jack for use with a regular guitar 1/4” jack which is a matching tip sleeve type.
So in short that type of cliff jack can only control 1 function.
A cliff jack would need to be a 6 lug type control 2 functions.
What are the 4 things you want to control with the foot switch?
That cliff jack in your photo is only what’s called a tip sleeve jack for use with a regular guitar 1/4” jack which is a matching tip sleeve type.
So in short that type of cliff jack can only control 1 function.
A cliff jack would need to be a 6 lug type control 2 functions.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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johnnyreece
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Re: Help with 4 way footswitch
I found this on Reverb.
https://reverb.com/uk/item/84475924-ham ... e-20-combo
Pictures show an actual four button footswitch. No clue how that could be implemented...In looking at pics of one of their other amps, it looks like the wiring goes to a board with some type of microcontrollers or something. Sorry I can't be of more help...
https://reverb.com/uk/item/84475924-ham ... e-20-combo
Pictures show an actual four button footswitch. No clue how that could be implemented...In looking at pics of one of their other amps, it looks like the wiring goes to a board with some type of microcontrollers or something. Sorry I can't be of more help...
Re: Help with 4 way footswitch
After seeing the actual footswitch my comments above are obviously wrong.
...Steve
Re: Help with 4 way footswitch
this is the footswitch
because only two + ground wires are used only some kind of voltage shifting in the pedal is probably implemented
probably some resistors, diodes or zener diodes
maybe something like Fender implemented (check attached picture)
because only two + ground wires are used only some kind of voltage shifting in the pedal is probably implemented
probably some resistors, diodes or zener diodes
maybe something like Fender implemented (check attached picture)
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johnnyreece
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sluckey
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Re: Help with 4 way footswitch
Now that's funny! I don't care what anybody says. Everybody knows that uneven tire pressure is the major cause for crackling sounds in amps.johnnyreece wrote: ↑Tue May 12, 2026 5:47 pm I can't believe it. If I said my amp was crackling and you told me to change the oil in my car, I wouldn't even question it.
...Steve
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Stevem
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Re: Help with 4 way footswitch
Looks like a simple build.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Help with 4 way footswitch
I'd like to see a schematic showing the circuit connected to that footswitch jack inside the amp chassis.
...Steve
Re: Help with 4 way footswitch
Yeah, I looked at Hamstead's current offerings, and they indicate the footswitch is TRS. You've got a simple mono jack there.
Perhaps, this particular (prototype?) amp doesn't implement every feature of the later production amps.
There are a lot of ways to skin this cat. Fender did this by supplying low-voltage AC to the pedal, with just enough current to drive 2-4 LEDs. The switching logic would rectify the return current and send the positive half of the AC waveform to one set of voltage comparators, and the other half of the AC cycle to second set of comparators. The pedal switches would close and light the leds and change the cycle voltages.
It only requires a guitar cable. A little hard to wrap your head around, but it works.
If it is DC, then there's probably a resistive ladder with say, 4 steps. This works just like a 4-bit D/A converter. It can produce 16 discrete current levels based on the combination of closed switches. A switch, LED and a resistor are in series. Pick the LED's and resistors to get different discrete levels.
On the inside of the amp, there's an I/V converter that senses the current in the pedal loop, converts to voltage and then comparator circuits do the logic.
Perhaps, this particular (prototype?) amp doesn't implement every feature of the later production amps.
There are a lot of ways to skin this cat. Fender did this by supplying low-voltage AC to the pedal, with just enough current to drive 2-4 LEDs. The switching logic would rectify the return current and send the positive half of the AC waveform to one set of voltage comparators, and the other half of the AC cycle to second set of comparators. The pedal switches would close and light the leds and change the cycle voltages.
It only requires a guitar cable. A little hard to wrap your head around, but it works.
If it is DC, then there's probably a resistive ladder with say, 4 steps. This works just like a 4-bit D/A converter. It can produce 16 discrete current levels based on the combination of closed switches. A switch, LED and a resistor are in series. Pick the LED's and resistors to get different discrete levels.
On the inside of the amp, there's an I/V converter that senses the current in the pedal loop, converts to voltage and then comparator circuits do the logic.
Re: Help with 4 way footswitch
when I plug the cable in the footswitch jack, only normal channel led is lit and all the switches on the front panel are disabled
tried decade resistance box with ammeter in series and LED diode
changing resistance, current was measured from 1mA to 80mA (this without LED), nothing changed, only normal channel led stay lit
I'm totally confused
tried decade resistance box with ammeter in series and LED diode
changing resistance, current was measured from 1mA to 80mA (this without LED), nothing changed, only normal channel led stay lit
I'm totally confused
Re: Help with 4 way footswitch
Can you trace out where the wire to the jack leads and photograph the circuit, or even better sketch out a schematic?
Re: Help with 4 way footswitch
wires from Cliff jack goes to large PCB on the front
that PCB contain so many IC chips , so it will be impossible to trace, at least for me
that PCB contain so many IC chips , so it will be impossible to trace, at least for me
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