Duotone footswitch

I just bought a duotone head a couple of days ago and don't think it is coming with a footswitch. Is there a replacement one that H&K makes or another company?



Thanks, Fuzz

I don't know the Duotone and there are no schematics out there as far as I know but...

H&K usually stick to a simple switching system where the relevant function pin at the footswitch socket is just grounded to engage each switch.  That should be tested first and that will be easy to do.  Your Duotone has an XLR socket rather than just a 1/2" jack as it has to cope with 3 switched functions not just 2.  The XLR wiring will be unusual.  An XLR plug for a microphone will be set up so the two signal lines are on pins 2 and 3 and the ground/screen line is on pin 1.  There is a fourth spring terminal which connects to the plug shell when it is assembled and this can be attached to pin 1 also but it is not necessary.  You need the three pins for your 3 control lines and so the outer screen must provide the ground.   Work on the XLR socket of your amp with a short piece of wire.  Short any of the three signal lines to the locking tab with the wire and see if the amp switches.  If it does then test all three pins to see if each function is covered.

I have mocked up a pic of an XLR switch wired as I reckon yours will need to be.  The three signal lines from the switches are Red, White and Black and the outer screen is the silver.  You can see that it is fitted to the fourth grounding terminal of the plug usually only used to connect to the shell.  That would be the only way to carry a fourth ground line in through a 3 pin XLR cable as you have.

Try that test first which should confirm that I have all of those assumptions correct and that the switching arrangement has absolutely no frills or special requirements other than connections.  If that works as it should then you simply need to source any simple 3 button footswitch.  There is nothing unique about most of them.  The only complication will be the XLR plug on the cable.  Some footswitches use a dedicated fixed cable which is in place all the time, others use a removable one, it makes no difference.  You simply have to arrange the amp end to match that 3 pin XLR.  Remember, the outer screen will have to be kept separate from what is the normal ground line so the wiring will not be what you find online for the more usual microphone type cable.  The three signal lines will connect to the 3 normal plug terminals numbered 1, 2 and 3.  The ground will be carried through the cable braid if it is screened.  That is attached to the fourth 'spring' terminal which wipes onto the plug shell when it is assembled.  Your cable has no need to be screened in any way, it can be a simple light four core flexible type.  These voltages and currents being fed through it are only light duty DC.  There are no noise pickup or radiation issues to worry about.

If you have LEDs in your footswitch these should simply be fitted in series with the switches with their cathodes to ground.

The H&K own brand 3 switch FS-3 footswitch is suitable.  It seems to be available for about £40 in the UK.  That one has a fixed cable which is good but it terminates in a 5 pin Din socket which is no good.  You will need to remove that and fit an XLR plug.  Do you have good soldering skills or do you have anyone who could do that for you?

Thank you so much!!!!! I will look into the FS-3 first. If not I will see if switch dr could build me one. FS-3 seems like the way to go.