Stasis Leak : tap tempo rate led noisy. How can I connect it differently ?

[eh la bas ma]

Hello,

I built a Stasis Leak circuit some time ago, and I can't find a way to supress the clicking noise when the tap tempo is activated.

Without the led, it's perfectly silent, Tap tempo works without clicking noises. I tried all kind of led resistor, up to 22k, but I can't get rid of the noise.

Usually, this rate led is lighting up only when the tap tempo is engaged. If I turn the Speed control, it disengages the tap tempo setting and the led goes off.

I wonder if I can wire the tap tempo led somewhere else, for exemple as rate led always on ? In a way that won't make any clicking noises ?

https://frequencycentral.co.uk/wp-content/uploads/GT-Stasis-Leak-Build-Doc.pdf

https://frequencycentral.co.uk/wp-content/uploads/GT-Stasis-Leak-schematic.pdf

I should mention that I damaged the board with the DC jack's screw. It doesn't appear to have any impact on the effect, I am not sure what the damaged trace does (damaged aera circled in red) :



Every suggestion and observation are welcome !

Edit : here is a picture of the build. Blue and red wires in the middle are connecting the status led to the tap tempo led, used as an additional status led for now.

[Paul Marossy]

Have you verified that it's not the LED itself that is the cause of the noise when in that mode? Also how are the wires routed to the LED? I'm wondering if maybe it's a wiring issue, like those LEDs wires might be too close to other wires which might be picking up switching noise.

The damage to the PCB, if it's not shorting anything together and/or none of the copper tracks are severed, it's just cosmetics. That wouldn't affect anything.

[eh la bas ma]

Have you verified that it's not the LED itself that is the cause of the noise when in that mode? Also how are the wires routed to the LED? I'm wondering if maybe it's a wiring issue, like those LEDs wires might be too close to other wires which might be picking up switching noise...so I disconnected it.

The damage to the PCB, if it's not shorting anything together and/or none of the copper tracks are severed, it's just cosmetics. That wouldn't affect anything.

Thanks for your reply !

Yes it's the led itself i guess : there isn't any ticking noise when i disconnect the tempo led. I tried a yellow led, a red led, a 3mm red led, and still some noises... so I disconnected it.

there are wires on one led because I disconnected the tempo led from its pcb pads, and connected it to the bypass status led, just to make some use of it. Now i have both leds lighting up when the effect is switched on, the tap tempo works without any noises, but I don't have any rate indicator.

When the tempo led was connected to its pcb pads, I had some ticking noises synchronized with the tap tempo. There wasn't any wires then, just soldered to the pcb.

I wonder if there could be an other way to get a speed/rate indicator, without noises ?

[antonis]

I'd try to split R56 1k resistor into 470R + 560R, or just add another resistor of 470R say in series with R56, and place a 10μF cap between resistors joint and GND..
(it might cause a slight delay but I think it should be unperceived..)

[Paul Marossy]

there are wires on one led because I disconnected the tempo led from its pcb pads, and connected it to the bypass status led, just to make some use of it. Now i have both leds lighting up when the effect is switched on, the tap tempo works without any noises, but I don't have any rate indicator.

When the tempo led was connected to its pcb pads, I had some ticking noises synchronized with the tap tempo. There wasn't any wires then, just soldered to the pcb.

I wonder if there could be an other way to get a speed/rate indicator, without noises ?

OK well I thought it might be a long shot but worth a try to check that out. I've had dodgy LEDs on occasion.

[eh la bas ma]

I'd try to split R56 1k resistor into 470R + 560R, or just add another resistor of 470R say in series with R56, and place a 10μF cap between resistors joint and GND..
(it might cause a slight delay but I think it should be unperceived..)

Thanks for your suggestion !

I tried and unfortunately there isn't any noticeable change. Ticking is still synchronized with the rate led.

I soldered a 470R and 1K resistors together, with positive side of a 10uF soldered to the resistors joint, and negative side to DC ground. I tried a red led soldered to its respective rate led pads, and then with the led + side to D5 negative side, and led negative side to momentary switch ground pad :

[Ripthorn]

Put a 1k resistor between LED and ground. I know there is one between chip and LED, but I've had similar problems with KED noise and microcontrollers before.

[eh la bas ma]

Put a 1k resistor between LED and ground. I know there is one between chip and LED, but I've had similar problems with KED noise and microcontrollers before.

I tried 1K resistor between led negative side and ground, without Antonis's fix. Unfortunately the ticking is only getting louder.

[antonis]

FWIW, there is a discrepancy about pins numbering, hence connections.. 

https://frequencycentral.co.uk/wp-content/uploads/Belton_ABE.pdf
https://www.tubesandmore.com/sites/default/files/associated_files/p-r-abe.pdf

[anotherjim]

If you use an audio probe on the +v power (pin1?) of the Belton module, my guess is that you will hear the same clicking. We may not know what the module does about power filtering but I'm surprised a resistor is used to drop the voltage without also having a filter capacitor after it to suit.