Jump to content

What is necessary to build a pedal that combines a guitar's & a synth's signals well?


hangwire

Recommended Posts

  • Members

I have revisited this idea recently... what is necessary to build a pedal/device that can have a synth signal and a guitar signal both run into it, and into a chain of effects to one amp input?

 

I have tried an ABY box in reverse, but the guitar signal usually gets mauled in teh process... I even had a little mixer, but again, dealing with an extra 2 stages of volume control took a bit too much from my signal and was a pain to try and set up quick for a gig...

 

 

...so what is the trick? a box that can take 2 signals and make it 1 decent signal... I imagine a TB type looper where teh guitar signal is untouched, but then the synth signal's input would need a converter or something to combine without interferring with guitar quality....

 

 

any ideas?

Link to comment
Share on other sites

  • Members
Originally posted by ck3

240.jpg

I had something similar but it has channel and a master volume.... it sucked a lot of character from the guitar signal... is the DOD better in that regard? does it interfer with self oscillating fuzz/do you have to remember to put those pedal before the mixer...?

Link to comment
Share on other sites

  • Members

...and I am not TB pureist in the least, so it REALLY made teh guitar sounds crappy... not just a bit of coloring that I could EQ out with the amp... it was like sticking a peice of tracing paper under the strings...

Link to comment
Share on other sites

  • Members

I've never actually used one ... so I can't comment in that regard. :(

There is also a comparable unit manufactured by Behringer if this one does not offer the features you seek ... but I'm not certain if it has been released stateside yet.

Link to comment
Share on other sites

  • Members

Originally posted by jdwinger



The DOD is a passive mixer, basically 4 volume controls in parallel


Was you mixer passive or active?



Will it interfere with a self-osc fuzz? If the oscillation is just produced by passively tying the output to the input, just about anything can effect that (as stuff hanging off the output or the input are going to effect the RLC of the feedback loop...If the feedback loop is buffered from the input and output, then you should be OK, but most folks are prob just tying the output to the input)

 

 

the mixer I used was powered with a 9V, so I guess active... so the dod resistance mixer is passive and should work? does that mean that at full volume it is full volume of the incoming signal, and as you turn down you are limiting?

Link to comment
Share on other sites

  • Members

well like i said... it would be just for a guitar and a synth to combine to go through my pedals... so hopefully that would be enough... but still, what would it take just to build a 2 input in and 1 input out pedal... and have it work the way I would like it to work? what would the guts need to be?

Link to comment
Share on other sites

  • Members

Are you going to have two people playing two different instruments (guitar and synth) and then combine the signals and run it into one amp?

Or are you going to use a guitar with a synth pickup and then combine the two signals?

I ask becasue I think there are already electric guitars with synth setups that feature blend controls - like the Brian Moore iGuitar USB.

Link to comment
Share on other sites

  • Members

what about a Boss LS line selector. I have it in my setup where i have both guitar and synth into it, and one output into my pedal chain. I have it set up so when bypassed, its just my guitar (for when i have distortion, i don't want all my keyboard noise in there), and when engaged, its both guitar and keyboard.

Link to comment
Share on other sites

  • Members

I've been doing a lot of switchers recently that have had a little op-amp based mixer in to blend either a wet & dry signal or two different effect chains. They've all gone to gigging musicians, and I've had reports back from all of them that they work perfectly.

Link to comment
Share on other sites

  • Members

Originally posted by dot-dot-dot

I've been doing a lot of switchers recently that have had a little op-amp based mixer in to blend either a wet & dry signal or two different effect chains. They've all gone to gigging musicians, and I've had reports back from all of them that they work perfectly.

please tell me more!

 

 

 

 

and my fuzz is a EX Parallel Universe... and yeah, I change pitch with teh volume/tone knobs on the guitar... but I have no problem running guitar-PU-mixingunit-rest of pedals

 

 

and I would have the synth on top of my amp and play it while the guitar is just hanging there so I can strum in between chords on the snyth... or have my loop going in a delay pedal... i was just working on having pedal effects for my synth again without having to buy a set up...

Link to comment
Share on other sites

  • Members

The board that does it is about 1" by 2". One op-amp, a few resistors, a couple of pots if you want individual level controls (or it can be built to give unity gain throughout). It does buffer the signal, so putting a FF style fuzz after (or any effect that relies on seeing a low output impedance from the preceding stage rather than being designed to work anywhere in the chain) might not give great results.

Sound-wise it's neutral; it's a standard textbook design - I don't believe in being clever when being dumb works perfectly well. :)

The PU is a lovely design - the oscillation should be unaffected by position in the chain - but I'd suggest guitar -> PU -> mixer unit.

In my view passive mixers are complete crap. You can get a certain mileage out of a simple blend pot, and in a lot of rigs it'll work fine, but I like the "engineering" approach - use a simple active circuit.

If you remind me later today or early tomorrow (so I get it tomorrow morning) I don't mind giving you the schematic, provided you don't pass it around or post it on the web. :)

Link to comment
Share on other sites

  • Members

Originally posted by jdwinger

I'm not familiar with the design of that unit, but if you are changing the sound with the volume control

5 will get you 10 it's just tying the output to the input so that will be sensitive to being run behind a buffer (ie it won't "see" a change in loading through the buffer)


A passive mixer could also effect it howeve (as it will see the loading from all the channels, though these might not change much so you could trim the unit to that)



Any idea what the input impedence of the mixer was? (if it was a "line mixer" the input impedence of the mixer itself may be loading the guitar down too much)

 

 

the 1st paragraph made no sense to me... sorry of my ignorance...

 

 

i am not sure... it was a cheapy thing... the mixer that is...

 

 

so 3 jack, 2 pots, and wire and see what happens? any of those jacks need to be stereo?

Link to comment
Share on other sites

  • Members
Originally posted by dot-dot-dot

The board that does it is about 1" by 2". One op-amp, a few resistors, a couple of pots if you want individual level controls (or it can be built to give unity gain throughout). It does buffer the signal, so putting a FF style fuzz after (or any effect that relies on seeing a low output impedance from the preceding stage rather than being designed to work anywhere in the chain) might not give great results.


Sound-wise it's neutral; it's a standard textbook design - I don't believe in being clever when being dumb works perfectly well.
:)

The PU is a lovely design - the oscillation should be unaffected by position in the chain - but I'd suggest guitar -> PU -> mixer unit.


In my view passive mixers are complete crap. You can get a certain mileage out of a simple blend pot, and in a lot of rigs it'll work fine, but I like the "engineering" approach - use a simple active circuit.


If you remind me later today or early tomorrow (so I get it tomorrow morning) I don't mind giving you the schematic, provided you don't pass it around or post it on the web.
:)


this sounds cool... ideally I would like the guitar to be unity and have a pot for the synth since I am sure it will have to be blended in... but yeah, whatever to try and build...... email the scheme to me jadczak@hotmail.com ... I would much appreciate it... and of course... i am not selling/over exposing...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...