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Mixer return for guitar pedals?

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Mixer return for guitar pedals?

Postby al_diablo » Sun Mar 29, 2020 2:24 pm

I've got a Mackie 1620i mixer and have been trying to move away from using the computer recently, so would like to use some of my collection of guitar pedals as effects with the mixer.

Some, like the eventide stuff, have switchable impedance. I also have a digi tech digital multi fx that doesnt seem to mind being used on a send.

For analogue pedals I thought it probably worth getting a reamp box to match the impedance so I bought a palmer one. Ive subsequently read a pedal with a buffer probably would have done the same job?

Edit - sorry, this probably isnt the right forum but I couldnt see a way to move the post

My main question is, should I run the output from the pedals straight back to the Mackie returns, use a DI box before going back to the return or run the pedal output into the hi-Z channel of the mixer?

Is there a correct way to do it, and more importantly is there a way to NOT do it so I make sure not to break my gear?

Thanks!
Alex
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Re: Mixer return for guitar pedals?

Postby blinddrew » Sun Mar 29, 2020 2:40 pm

The output from a guitar pedal should be happy going into the hi-z input. You might be fine going into a line input but would probably need to crank up the gain.
Similarly if you go from a line out to a pedal you'll need to start at minimum and slowly bring it up.
The only thing that might damage anything really is phantom power.
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Re: Mixer return for guitar pedals?

Postby Hugh Robjohns » Sun Mar 29, 2020 4:55 pm

al_diablo wrote:For analogue pedals I thought it probably worth getting a reamp box to match the impedance so I bought a palmer one. Ive subsequently read a pedal with a buffer probably would have done the same job?

The 'impedance thing' is a huge and irrelevant red-herring when you're connecting FX pedals to a mixer (or interface).

Whereas a guitar is fussy about seeing a high-impedance destination, a mixer send really isn't. And similarly, the output of the pedal really doesn't care about the impedance it is feeding either, as long as it's more than a few kilo-Ohms. So you can forget all that impedance nonsense (in this instance, anyway ;-) ).

What you do need to think about in this situation are the signal levels, connecting balanced and unbalanced interfaces, and possibly ground loops (if using mains power-supplies to run the pedals).

Most mixer (and interface) line inputs are balanced these days, and many outputs will be too. However, a lot of interfaces and mixer use the so-called impedance-balanced type which will work perfectly happily with either balaned or unbalanced destinations). Most Mackie consoles use impedance-balanced outputs on the Aux sends, for example.

Most pedals have unbalanced inputs and outputs, of course.

So an instrument TS cable from the mixer to the pedal, and another from the pedal to a line input will usually get the job done (but see below)

My main question is, should I run the output from the pedals straight back to the Mackie returns, use a DI box before going back to the return, or run the pedal output into the hi-Z channel of the mixer?

The first (line inputs) and last (hi-z inputs) will both work fine, although you'll probably need to dial in some gain if going into a line input.

The second is also an option, but you'll need to connect the DI output into a mic input of course, rather than a line input, because DI boxes take the instrument input and reduce it to mic level (and some DI boxes require phantom power to work).

Balanced line inputs can accept an unbalanced pedal output if connected with a standard instrument (TS) cable, and that's what I'd advise for starters. If you are having problems with ground loops then you can get clever using a pseudo-balanced cable or a line transformer box or a DI box (via the mic input)... but rather than overload you now, it's easier to cross that bridge if or when you get there!

...is there a way to NOT do it so I make sure not to break my gear?

As Drew says, the only potentially serious risk to the equipment is stuffing 48V phantom power up a pedal's output... but that can only happen if you connect a pedal directly to the XLR mic input of the mixer -- which isn't very likely.

If you decide to use the mic inputs, always connect via a DI box! Simples ;-)

The other thing is a more practical one, which is that pedals generally expect instrument level inputs (-20dBu-ish) while an Aux send from a mixer will be a nominal +4dBu and could be as high as +20dBu if you're pushing the levels (or using an interface with signals peaking close to 0dBFS). Such high levels will obviously result in overload distortion... which may not be the effect you're trying to get! :-D

So, when connecting and setting up, always start with the send/input levels turned right down, and advance them slowly and carefully! Keeping both the channel Aux send and Aux Masters fairly low (below half-way) typically makes things usable.

Alternatively, use a reamp box between the mixer/interface output and the FX pedal input. A Reamp box takes care of the necessary level adjustment, as well as the balanced-unbalanced conversion and also provides galvanic isolation (to help prevent ground loops) as well.

I like the Orchid Electronics Amp Interface which is well made, easy to use, sounds great, and is very cost-effective, but there are plenty of others around of varying complexity, cost, and snake oil!

https://www.soundonsound.com/reviews/orchid-electronics-amp-interface
http://orchid-electronics.co.uk/Amp_Interface.htm
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Re: Mixer return for guitar pedals?

Postby Arpangel » Mon Mar 30, 2020 8:41 am

I’m using a few pedals with my mixer, just plugged into the aux sends, and channel inputs, I don’t use reamp boxes or DI's, it all works fine......as long, as you keep the levels down, and use unbalanced cables throughout.
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Re: Mixer return for guitar pedals?

Postby al_diablo » Mon Mar 30, 2020 9:36 am

Thanks all

I was hoping I'd not have any issues but didnt want to knacker my lovely boutique overpriced drives and fuzz
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