Help with idea for splitter/effects loop pedal

[orangetones]

A friend asked me if we could build a pedal that is like a signal splitter, but instead of just splitting the signals, one signal passes through, and the other gets sent to some outside pedals, but then mixed back into the original signal.  The signal that gets sent, returns, and then mixed with the original will also need to limit the frequencies.  Say I want to send everything above 500Hz through the loop or say I want a variable cutoff adjustment for the frequencies that go through that loop.

When the pedal is not engaged, it would act as a pass through.

Thoughts?  Was looking at the amz buffer/splitter here.

http://tagboardeffects.blogspot.com/2014/08/amz-2-channel-splitter.html?m=1

[idy]

What you want is from the same source: the Splitter Blender
http://tagboardeffects.blogspot.com/2012/02/split-n-blend.html

The experimenter's friend. You can couple it with any eq or tone control you want...maybe in separate boxes.... I build these with the send/return jacks as NC so when nothing is plugged in that loop is just a clean path, otherwise you need a jumper.

[orangetones]

So, that looks like it splits and blends, right?  And in the send/return path o could put in a high pass filter.

Seems my friend want as clear as he could have been.  He is now talking about a crossover and mix/blend pedal.

So... Any diy solutions for a crossover?  Where I can have an effects loop on the high side? Which then gets mixed back in with the low side?

[orangetones]

https://www.diystompboxes.com/smfforum/index.php?topic=112437.0

Found this thread, which seems promising, but never made it to fruition.

Would love if someone would help me with through this problem.

[BJM]

You want to build something like this?

https://diy.thcustom.com/shop/pro-cessor-v4-0-pcb/

It's a splitter/blender with LP/HP filters.

[eh la bas ma]

I built a pro-cessor (march 2021), I can tell it's a great tool, there are various ways of using it. It's a creative tool, it gives you ideas.

It's always on, I mostly use it to play with many pedals, like two pedal boards, and i can quickly compare circuits or blend both with one pot.

My only "problem" now is that i always have like 20 pedals connected in front of me. It might be a bit too much and it's hard to explain to people when they pay me a visit : "here we have 3 compressors, I have to try all three before I decide which one sounds the best with these other circuits"...

I get caught with all the possibilities and spend most of my time doing tests and trials instead of playing with simplicity.

I hope it will help you and your friend. Pro-cessor is great, but you must be strong, focused...

[orangetones]

You want to build something like this?

https://diy.thcustom.com/shop/pro-cessor-v4-0-pcb/

It's a splitter/blender with LP/HP filters.

Looks promising, but ideally I would want an adjustable frequency split.  How would we effectively implement that is the question.

[PRR]

> I would want an adjustable frequency split.

Variable frequency crossover is better bought than built. The Rolls is 90 bucks new. The music pawn shop may have more.

[orangetones]

> I would want an adjustable frequency split.

Variable frequency crossover is better bought than built. The Rolls is 90 bucks new. The music pawn shop may have more.

Why better bought than built?

[idy]

Better bought than built because it's actually a pretty thorny non-trivial problem. A high pass and low pass that dial together... Notice the Rolls uses a rotary switch with 10 or 12 pre-set frequencies. It's a really interesting problem and great question. Hope the engineers will chip in some solutions.

[PRR]

It takes 6 or 8 gangs to do hi/low filtering with good separation (18dB-24dB/oct).

You can't buy a pot-stack that long; anyway it would not track.

Stackable switches do OK but it is hard to get the switch made-up in quantities of less than 5,000.

The problem is no different than low-level speaker crossovers, which sell well so are well priced. I thought you'd have to buy either stereo or 3-way, until I saw that Rolls.

[idy]

Elliot Sound shows a state-variable crossover, first two bands then three!
https://sound-au.com/project148.htm

This looks possible, it mentions getting dual gang pots that track well. Only four opamp stages and the dual gang pot.

Maybe this is not a solution because 12 db per octave.