Serial/Parallel Switching

[machti]

Hi fellas

I´m having a litte problem with serial/parallel switching two Fx-untis.
I´ve decied to bild myself a little "filter box" in with an Nathan East Preamp and and State Variable Filter. To switch between S/P and I´m using an DPDT toogle switch between wired like this,



Master input comes from the instriment and after master output there is another volume pot for master volume.
In order not to overdrive the second Filter when run in series I put an volume pot between the first filter and the switch, as I turn down the trim pot completely there is no signal in series ( as expected) and in parallel mode which is quite unexpected and puzzeling to me. How can I solve this and why on earth does the volume pot after the first filter does silence both filters, I don´t have an explanation and I hope that you guys can help me out.

[Quackzed]

in parallel mode a out and b out are connected, so the volume pot/trim at Aout is also connected to Bout ... you could use a mixing stage after each... or something to isolate each output from the other... might be as simple as putting a 10k series resistor at the end of each output ( a and  b) after a's vol pot. thats passive and easy, but an active mixing stage will be better at isolating them and preventing treble loss...

[duck_arse]

^ reading qhile quack was typing. can you draw out your circuit with switches and pots, so we can all see where is going what? a circuit diagram will often clear-up what a mechanical drawing won't show.

[is it possible for fingers to have dyslexia?]

[edit :] oh, and welcome to the forum.

[ashcat_lt]

Yep.  In parallel mode the wiper of that volume control is connected directly to the master output (or the master volume, which is essentially the same thing for this purpose).  When you turn it all the way down, it shorts the entire output to ground, taking the output of the other effect with it.  You could do what folks do with Les Pauls and wire that volume control "backwards" - switch the wiper and the outside lug which is not grounded.  But why would you ever turn that all the way down?

[machti]

Well ashcat_lt  thank you, so simple and jet it didn´t occur to me.  I don´t intend to turn it all the way down, it was more for the fun of it and I´m wasn't aware that the whole signal would be dumped.  Knowing this two separate volume pots after each filter should solve my "problem" I guess.

Is just dyslexia, English as a foreign language add a little no lets write it that way and there you go. I have ways to get around with dyslexia and do proofread a lot but it takes me quite some time to find all the mistakes I make und well this time I did take some time.

[duck_arse]

I've only just noticed "qhile" is not a real word.

I have only english, so although I can't name all the rules of syntax and content, I can generally follow them. a great many english as second language-ers are prone to put the words where they make sense. (why would you put them otherwise?) this often results in less messing, more pointing and more enjoyable reading. that probably won't translate.

a lot of the time I chuck the syntax rules, just cause I can.