Hi everyone,
in my box of rock I replaced the 3pdt with a dpdt switch with which I can have the bypass and the led but also because it is quieter when pressed and less bulky. With the 3pdt I did not hear the popping when I pressed the switch, now with the dpdt I hear this annoying bump and nothing changes even putting a 1Mohm resistor between the effect input and ground and between the output and ground.
Can something be done, even just to reduce this bump ?
Is this the same box as this thread?
https://www.diystompboxes.com/smfforum/index.php?topic=133212.0
No, another box, in that one no noise and it's also plastic. I had a Dpdt switch left and I wanted to put it in another pedal together with the millenium bypass but I had this problem.
Is this (https://hotbottles.wordpress.com/wp-content/uploads/2013/07/zvex_boxofrock_schematics.jpg) your circuit..??
If yes, there is no need for OUT pull-down resistor due to Tone pot & R26 already existence.. :icon_wink:
I suspect you have an LED pop issue..
P.S.
Could you post a schematic of exactly how you've wired DPDT switch..??
I'm getting tired of all those not greeting AIs.. :icon_mrgreen:
Quote from: antonis on May 22, 2025, 07:17:35 AMIs this (https://hotbottles.wordpress.com/wp-content/uploads/2013/07/zvex_boxofrock_schematics.jpg) your circuit..??
If yes, there is no need for OUT pull-down resistor due to Tone pot & R26 already existence.. :icon_wink:
I suspect you have an LED pop issue..
P.S.
Could you post a schematic of exactly how you've wired DPDT switch..??
Yes, the schematic is the one you indicate, but before answering I wanted to try again and in fact the problem is a bit there even without LEDs but to a much lesser and bearable extent while with the bypass system it is more annoying in the ON position even if I hear a bit of mechanical noise from the switch in the OFF position.
The schematic I used to wire the dpdt is this
(https://i.postimg.cc/SYRDFbd5/LED-Trick-funziona-PNP.jpg) (https://postimg.cc/SYRDFbd5)
Quote from: Lillian826Pena on May 22, 2025, 08:02:57 AMThe popping sound when using a DPDT switch in your "box of rock" pedal, which wasn't present with the 3PDT, likely stems from a DC voltage change at the effect's input/output due to your DPDT wiring not adequately discharging capacitors in bypass mode. The most effective solution is to rewire the DPDT switch to actively ground the effect's input when in bypass, similar to how some 3PDT true bypass setups work. Also, check for any accumulated DC voltage on the effect's I/O pads and consider capacitor replacement or a different power supply if rewiring doesn't fully resolve it.
With the 3pdt in bypass I actually grounded the effect input and this worked but with a dpdt I don't know what to do if I have to use the LED at the same time. Anyway, the power supply is a 1Spot and I've never had any problems and I prefer not to touch the box of rock circuit since it gave me a lot of headaches before working properly :icon_wink:
For now i put the 3pdt back
I would like to make a consideration, wiring the 2pdt and the 3pdt with true bypass and without led, I get the popping sound only with the 2pdt.
Could it be plausible that the problem could depend on the mechanical exchange inside the switch ?
Yes.
I've opened so many of them and from a mechanical point of view they all seem the same inside. But can't something be done ?
You could have a situation where the switch poles make contact in a different order than other ones you have made and something like the order of switching the input and output will make a huge difference in the amount of switch pop you get. And this order has to be considered for both switching positions.