Issue with Warmoth mod on D’lay build

[nazman]

Hey everyone!

New to this forum! First GuitarPCB build just recently with a D’lay kit. Have built a few pedals over the years so not a complete newbie. Will be building a Paramix very soon, already have the kit.

I’m in France so I get the kits from Klaus at Musikding, in Germany. Bless the man!

Right, so I’m having issues with the Warmoth mod on my D’lay, everything else seems to be working fine and the pedal is noiseless. I kept R-A at 8k2 and set TR1 to max (don’t know if that’s right but it seems to work fine). I first used an 82k resistor for R22 but wasn’t getting enough repeats so used a 150k instead (again it seems fine and as I say the pedal is pretty noiseless).

My problem is that when I press the momentary switch for the Warmoth mod nothing much happens. It kind of does a runaway repeat but hardly noticeable and only when the repeat & time pots are set to low (almost to zero).

So my question is: did I misunderstand the instructions? I soldered pin 1 of TR1 both to the board and to a lug on the momentary switch and then soldered a wire from the WF pad to the other lug of the switch. Was I supposed to solder pin 1 of TR1 only to the switch??? I’ve checked connections: lug1 of TR1 is connected to the WF pad when the switch is pressed down.

Here are some pics, as you can see I used a sardines tin as an enclosure.

 

[Billy]

I think you’d first need to set the trimmer so that with the repeats pot at max you get infinite repeats then you’ll know if your RA value is low enough

As you know pots have a tolerance of 20% so your 50K may be up to 60K which would affect determining your RA value

When you press the footswitch it bypasses the trimmer resistance going to lug 2 of the repeats pot and gives you just the value or RA temporarily taking the pot and trimmer out of circuit so you’d want to make sure your RA value is going to allow infinite repeats

Obviously make sure you’ve soldered the switch to lug 1 of the trimmer it’s not always obvious which is lug 1 and 3 the best way to determine that is to continuity check which trimmer pin connects to RA

[nazman]

Thanks for the reply Billy

If i understand what you’re saying, my R-A resistor value may be too high and that’s what’s stopping the warmoth mod from going nuts like I want it to? should I try 5k resistor instead of 8k2? Lower?

I’m pretty sure i’ve got Lug  of TR1 well located but I’m still wondering: does pin 1 of TR1 need to be soldered to the pcb AND the momentary switch or only to the switch????

[Billy]

Yes you would solder TR1 to both the pcb and switch

From the schematic when you press the switch it looks like you bypass the trimmer and pot so the only resistance in the feedback loop would be RA

The idea being you want it to give you a momentary blast of infinite repeats when you press the switch without having to alter the repeats pot but you’d also want it work normally when the switch isn’t pressed

So your RA value needs to be small enough to work in both scenarios

The way I would do it is socket RA and try different values set repeats to max then adjust TR1 until you get infinite repeats for normal use you should then get exactly the same when you press the switch with the repeats pot in any position

If you don’t there must be a mistake elsewhere

 

 

 

[nazman]

Ok thanks a bunch Billy, I’m gonna try this.

[nazman]

Put in a 4k7 resistor for R-A and it works just like I wanted it to… got a feeling something else was wrong but maybe it’s just me. Anyways, thanks a lot for the help!

[Author]

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