Noobie!!!!

[danielmount]

Sorry if this is in the wrong area!!!
I will try and explain this well, but i seem to frequently confuse myself whilst explaining it!!!
I'm looking to build a pedal that is like a looper, with an in, out, send and return, a foot switch, LED and a blend nob:
Pedal in bypass:
Signal in, out of the send, through pedals, in to the return, then to the output
Pedal Active:
Same as above but output is blended with the incoming clean signal.
Obviously this build will have a 3pdt f-switch, a pot and a led and some opamps. Though I'm struggling to find a schematic.
I'm confident enough to mess with schematics once i have one, but nowhere near able to make my own.
Can anyone point me in the right direction?
Any help would be very much appreciated.

D

[garcho]

Welcome to the forum!  

I'm confident enough to mess with schematics once i have one, but nowhere near able to make my own.

Making a schematic and designing a circuit are very different things.

You'll have to buffer your signal before blending it, so some pedals like Fuzz Face clones and some wahs might not sound the same, be forewarned.

Usually for custom things like this you'll waste a lot of time trying to find a schematic that fits your idea perfectly; it's better to piece one together from smaller building blocks.

Set up #1: FX loop without clean blend
Signal goes in through an input jack and goes to 'FX-out'. Wet signal comes in through 'FX-in' and goes to output jack. Well, that leaves no options for switching between blend and dry, so we'll need a switch somewhere. Let's look at set up #2

Set up #2: FX loop with blended clean
Signal goes in through an input jack and goes to FX out. Wait! Where does the clean signal come from, in order to be blended later? OK, it turns out you'll need an input buffer now. So, input jack to input buffer, then to FX-out, then FX-in and clean signal (from the buffer output) get blended via terminals 1 and 3 on a pot, with the wiper going to output jack. But then how to switch out of 'blend' mode? With a switch from FX-in to output that bypasses the blend knob, therefore bypassing the clean signal. So, now we have input jack => buffer => buffer output coupled through a cap to FX-out and a separate cap to clean terminal of blend knob => FX-in to both the switch and wet terminal of blend knob => switch to output from FX-in or from wiper of blend knob.

So it turns out the only schematic you'll need is a buffer. Those are easy to find.

Kinda make sense?

[danielmount]

I've read this about 10 times and I think it does. This seems to be a recurring problem when thinking about loops, my head ends up forgetting where i started!!!!
Just laying it out like this has been a big help in itself and given me direction.

[rutabaga bob]

Welcome aboard!  You'll like it here!

Larry

[jimilee]

Have yo had a look at the paramix over at gpcb?

[garcho]

Something like this:

[danielmount]

garcho:
Thanks for the diagram, it's as I thought from your description but seeing it like that makes my head hurt a lot less, just putting the send/return as a single unit rather than thinking of it as separate parts in the signal chain helps!! I'll get cracking on this today! Thanks so much buddy!!

Jimilee:
No I haven't Ill have to seek it out!! Thanks for the heads up man!

Rutabaga bob:
I have checked out this forum a few times though up untill now I have only done a few mods here and there. I love to tinker, so I imagine you guys will be seeing more of me  !!

P.S Sorry for the late reply, I'm based in the UK so our timings are a little off.

[danielmount]

Right, so after an evening of messing about I think i'm nearly there. Wiring wise, i think it's good. However I seem to be having issues with the buffer. Attached is the schem I followed with an added output for the blend (forgive the wrong direction of the ground).
The signal through the buffer seems to be very very quiet. It works, but really really quiet, so i wondered if this was because some of these values were incorrect. It's to be used on my active bass, could this be causing the problems?

Plus Garcho, is this what you meant for the added output with it's own cap?

[garcho]

check this out. Beavis Audio's buffer page.