Hearthrob Tremolo and Pulldown resistor

[Kost1978]

Hi to everybody,
just finished to build this trmolo, working fine beside the loud pop everytime I press the switch.
I saw in the blog post of the circuit someone mentioned a pulldown resistor, both on IN and OUT board switch PINs, so I put 2 1M res as shown in the picture, but I still hear a loud pop everytime I hit the switch:

Am I missing something? Did I put the resistors in the wrong place?
Thanks!!

[IvIark]

Personally I wouldn't connect the output pulldown resistor to the LED cathode lug.  Although in theory the ground there will be made when required, if the output pole makes even marginally before the ground pole then you could be adding to the pop as that ground circuit is made.  I'd go from the top right to left hand middle lug so you attach to a permanent ground, although you may have to stack resistors over each other or route them around a bit.

Failing that, try disconnecting the LED and see if that is causing the pop.  If it is you'll have to use one of Jack's methods here:

http://www.muzique.com/lab/led.htm

[Kost1978]

Thank you Mark,
I'll try everything you suggested and report back!

[Kost1978]

Ehi Mark,
I moved the pulldown res as you described, the pop sound is gone!

Thanks again!
P.

[IvIark]

Cool

[Lee]

Hi Kost, I have the same problem too. Could you please put on a pic showing how you made the change or wired the switch? Many thx!

[Kost1978]

Hi Lee, please check the picture i posted in my first comment, this is Mark's offboard wiring,modified by me in order to show the pulldown method, I simply added to the switch two 1M resistors. The picture is "wrong",after Mark's comment I moved the output pulldown resistor,solving my problem (I can't draw a new pic with the correct wiring right now,I'm not on my pc...).
Let's number the switch's pins in this way:
1  2  3
4  5  6
7  8  9
I wired the "input pulldown resistor"  to pins 5 and 8 and the "output pulldown resistor" to pins 3 and 4.
Hope this will help!

[Lee]

Thanks for your tips!

However, this is the way how I wired the switches. I did several layouts with this wiring. For example, the Super Hard On, there is always popping when switching even though I soldered two pulldown res both from input to ground and output to ground on board.

And this tremolo too, I soldered two pulldown res both from input to ground and output to ground on board and the pop still occured.

Some of my other builds do not have the pops, such as the Devi Ever Karaoke Party, Woolly Mammoth fuzz,  Trotsky Drive, and the JET buffer.

The pops quite bother me ...

Thanks for your help anyway.

[Kost1978]

Hi Lee,
I "fixed" the picture with the correct wiring I used, maybe you can try Mark's "Offboard Wiring" plus the pulldown as I did.
Mark's wiring is quite "bullet proof" as stated by many here, it also has some more grounding than usual wiring schemes:
"...it grounds the board input during bypass which will prevent noise bleedthrough that you can get with some high gain circuits."
Give it a shot and see how it goes!

[Lee]

Cool!

I will rewire the switch tmr!

Thank you for your detailed explanation and picture. I was disappointed but you just heartened me. Thank you again.

[Lee]

Good News！

I tried your way and the popping was almost gone! That's quite good enough for me! THX!

[Kost1978]

Great!
I'm happy to hear that Lee!

Have a nice day.