Mic'ing 2 instruments to a single amp

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Mic'ing 2 instruments to a single amp

Post by Dobrologist »

On stage, I use dobros. One is standard G tuned while the other is tuned Open E. I use a clip-on condenser mic through a tube pre-amp into my amp. However, switching the mic between instruments is a PIA. I have 2 mic's I can use but only one pre-amp and amp. Can I use an XLR Y splitter to supply phantom power to both mic's as well as feed the signal into the single pre-amp? Is there a better way on a musician's budget?
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Re: Mic'ing 2 instruments to a single amp

Post by MarkOne »

Sending two mics to one channel is probably not the best idea, if you think about it you are sending the signal from one mic up the output of the other. While this might not cause damage, it surely isn't how they were designed to operate.

I would look to get a small footprint mixer which had two mic channels and phantom power.

Something like this springs to mind.
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Re: Mic'ing 2 instruments to a single amp

Post by Hugh Robjohns »

I wouldn't recommend an xlr splitter. It can work in certain situations, but there's a risk of damaging the output stages of the mics, and the doubled phantom current draw will drag the phantom power supply voltage down potentially resulting in transient and peak distortion and/lower output level. You'll also have two constantly open mics, so any resonances from the unplayed instrument will colour the played one, along with double the level of on-stage spill.

So what you really need is an A/B mic selector switch box, allowing to select just the mic you want at any given time.

There are several commercial models to choose from, but there are more options if your mics are dynamics or self-powered rather than phantom powered.

This Q&A article has some suggestions:

https://www.soundonsound.com/sound-advi ... dal-and-pa
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Re: Mic'ing 2 instruments to a single amp

Post by Bob Bickerton »

I wondered about those but I think he wants to switch 2 mics to 1 output not 1 mic to 2 outputs. Can’t find anything that does that.

Might have to be a mixer maybe a Mackie 402 VLZ4?

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Re: Mic'ing 2 instruments to a single amp

Post by Hugh Robjohns »

Oops, sorry. Fingers typing without engaging brain.

The Radial Gold-digger is a well-engineered (albeit expensive) option, but it switches between 4 mics to one output so is overkill.

https://www.soundonsound.com/reviews/ra ... rry-picker

I think ART's mic splitter has a combiner mode, and will pass phantom to both...but you'd still have two permanently live mics.

A compact mixer might be the most practical option.
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Re: Mic'ing 2 instruments to a single amp

Post by resistorman »

MarkOne wrote: Wed Aug 17, 2022 5:11 pm
Something like this springs to mind.

^^This
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Re: Mic'ing 2 instruments to a single amp

Post by sonics »

I think you need a second tube preamp and then a switch box to select which of the two outputs goes to your amp.

If they are nice mics and preamps I wouldn't want to put them through a $100 mixer...
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Re: Mic'ing 2 instruments to a single amp

Post by Mike Stranks »

As already advised, XLR Y leads are not a good idea for 2:1 microphone use...

In your situation, I'd use a mic combiner. I have the IMG Stageline version which works well. EMO do a classier - and more expensive - one, the E345.

If you're in the UK...

https://www.ebay.co.uk/itm/155111658667 ... A#shpCntId
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Re: Mic'ing 2 instruments to a single amp

Post by Dave Rowles »

I've done this live many times with SM57s, but not with condensor mics. Always with the 57s you're adding waaayyy more gain than you would otherwise, but it solves a rather unique situation on stage that doesn't require stage monitoring outside of IEMs.

I'd really like to steer you away from this. Splitting things with phantom will probably end up causing damage. If you really want to try it, I'd send Orchid Electronics an email to see if there's something they could create to help.
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Re: Mic'ing 2 instruments to a single amp

Post by Bob Bickerton »

Mike Stranks wrote: Wed Aug 17, 2022 10:11 pm As already advised, XLR Y leads are not a good idea for 2:1 microphone use...

In your situation, I'd use a mic combiner. I have the IMG Stageline version which works well. EMO do a classier - and more expensive - one, the E345.

If you're in the UK...

https://www.ebay.co.uk/itm/155111658667 ... A#shpCntId

That looks like a handy little thing - not wired to pass phantom power unless ordered from Canford.

And actually Canford have an ex-demo model available for a similar price: https://www.canford.co.uk/Products/98-1 ... ER-ex-demo

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Re: Mic'ing 2 instruments to a single amp

Post by resistorman »

Bob Bickerton wrote: Wed Aug 17, 2022 11:51 pm
Mike Stranks wrote: Wed Aug 17, 2022 10:11 pm As already advised, XLR Y leads are not a good idea for 2:1 microphone use...

In your situation, I'd use a mic combiner. I have the IMG Stageline version which works well. EMO do a classier - and more expensive - one, the E345.

If you're in the UK...

https://www.ebay.co.uk/itm/155111658667 ... A#shpCntId

That looks like a handy little thing - not wired to pass phantom power unless ordered from Canford.

And actually Canford have an ex-demo model available for a similar price: https://www.canford.co.uk/Products/98-1 ... ER-ex-demo

Bob

It does look good, but the original post implies that they want to switch between two instruments, this would leave both mics hot.
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Re: Mic'ing 2 instruments to a single amp

Post by MarkOne »

sonics wrote: Wed Aug 17, 2022 9:51 pm
If they are nice mics and preamps I wouldn't want to put them through a $100 mixer...

Except that it then goes to some variable quality FOH system probably in a venue that is not acoustically ideal, and you'll be playing over the hubbub of conversation and many clinking glasses... And that's in the Royal Albert Hall! It will be worse in the Pig and Whistle on the High Street :o:o:o
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