2 channel Fuzzbox. Switching

[AM]

Hi,
After finding out my favorite gain settings on my fuzzbox, I replaced the gain pot with two different resistors attached to a 3pdt footswitch.
Now, the problem.....when I switch between low and high gain I get the dreaded PLOPPP sound.
If my deay is on it becomes PLOPPP , PLOPPP , PLOPPP

I understand that this is happening because of the mechanical switch. Is there any other quieter switch? I remember using a dpdt as ON/OFF switch on another pedal and I think the mechanical noise wasn't so loud. Still though....as part of a gain circuit even the dpdt wouldn't do the trick.
I thought of a toggle switch but I don't think they are too foot friendly. A relay might have worked but I'm trying to keep the circuit simple and as low current as possible.

I tried the pedal both live and in the studio for some months now and I absolutely love the sound. The only thing left now is to find a solution for the gain switch.

Thanks in advance for any input

[alanlan]

One solution may be to have one resistor permanently in circuit and switch the second across in parallel.  You'll need modified values though.  Obviously, Ra and Rb in parallel would be the same value as the lower of your 2 resistors and Ra would be the value of your higher of the 2 (assuming that Rb is the one which is switched across). 
Get my drift?
That way you never have a momentary open circuit which might be causing your plop.

[petemoore]

  Perfectly good suggestion.
  You can know by using a different switch for the gain if that 3pdt is bad [doubtful, but what else is there?] and if something else going through that switch? is causing the popping.

[AM]

Thanks for the replies guys!
I have the resistors wired in series. A rough diagram should look like this:



>---Rb=Low gain channel------                             /----------->
                                           /      /-------/         /
                                          /      I    I    I        /
                                         />---I    I    I---->/
                                                I    I    I
                                               /--Ra--/

So, so far I've been just adding the Ra on top of the Rb. Do I still get a momentary open circuit with this arrangement?

[lcv]

Hi,
yes you have,
try this connection instead...

>---Rb=Low gain channel------                               
                                            /                           
                                           /     I    I    I           
                                          />---I    I    I           
                                        /        I    I    I         
                                      /--Ra--/--------------->

..so that you have always a DC path .

Bye,
lcv

[AM]

Thanks. I guess this is the way I should do the parallel resistor wiring that alanlan talked about.
One question. Isn't a 3pdt a waste for this wiring? A spdt should suffice, no?
Something like this:

>---Rb=Low gain channel------                              
                                           /                          
                                          /     I            
                                         />---I            
                                       /        I          
                                     /--Ra--/--------------->

If I understand this right, it's like switching between series and parallel connection of the resistors.
My original values for the two resistors were 100k and 470k. So my low gain channel had total R=100k ad my hi gain channel had total R=570k.
If I want to keep the low gain channel near the 100k value I have to use an 1M resistor in parallel. This will give me 90.0k for the low gain channel and 1.1M for the high gain channel though. Is there a way to stay closer to my initial values?

[lcv]

Hi AM,
No, the set up I suggested keeps your (sound) concept of Rb in series w/Ra.
So Rb and Ra are in series, and the switch simply short circuits or not the Ra's leads.
Yes, a single switch will do but I suggest you to just try it with with what you've got, to see if the pop is minimized.
Since it works (soundwise) I would not touch the R values!
Of course this would be my approach, many others would work...

Regards,
lcv

[AM]

Oooops...I should stop posting late at night. Especially after a very long day. I see now that what I called parallel is anything but.....
Thanks for the suggestion lcv. I will try it.

[AM]

I decided to try both lcv's and alanlan's suggestions and see what works best. I calculated the new resistors values for alanlan's suggestions and I'll get them tomorrow. One thing i wanna make sure is if I understand  the way I should do the parallel wiring so I don't get the momentary open circuit.


                                     >-----/----------------R1----------------/----------->
                                            /                                            /
                                           /                  I    I    I              /
                                          />-------------I    I    I--------->/
                                                             I    I    I
                                                             /--R2--/

Please have a look and let me know if the above diagram is correct.
I will try both solutions and see what works best.

[AM]

Ok, latest update,
lcv, I tried your suggestion but unfortunately it didn't work. Thank you for taking the time to offer some help. I really appreciate it.
I wish it had solved the problem. Now, I don't know if it makes sense to go buy the extra resistors and try the parallel wiring.
I mean, with what I tried already I removed the momentary open circuit situation. The fact that it still pops probably means that this is not the problem, but the noise is just mechanical noise from the switch, right?

[lcv]

Hi AM,
Let's not give up so quickly, which effect are you talking about?
Knowing the schem would clear to me some doubts (e.g. if the overall ra+rb value is setting  some critical  DC biasing).

The mod is trivial, should NOT pop that loud. BTW some pop is unavoidable for capacitive effects but it's second order..
Regards,
lcv

[AM]

Hi lcv,
It worked!!! There is still a tiny bit of a clicking sound but of the same more or less intensity as the ON/OFF bypass switch. It is WAY less than before.
Both switches give less clicking sound than any of the commercially available true bypassed effects I own.
With what you suggested I didn't have to modify the existing board at all. I also took the opportunity to rewire all switches and jacks to the board neatly and now everything is good and tidy in there.
Thank you so much for your help. I owe you a favor  .

[lcv]

Great!
FYI, I'm using a 2channels dist too and I could not imagine now how could I  do without it playing w/the band...

Regards,
lcv