How to connect two instrument output signals into one?

[Steve Lipsey]

Stereo guitar. One Fishman, one Lollar Silver Foil. Want the Fishman to go through a JD Aura, the Silver Foil to go through an overdrive. Both lines need to end up in a mono signal to some more effects and then to an amp.

I'll switch between them on the guitar, so only one line will be "active" at a time. Probably. It may be possible that I'd want both on at once occasionally (e.g., JD says that that lets him add some bottom end to his dobro, although he uses two totally separate signal paths and amplifiers). I'd give that up if it meant having to add more electronics....

Can I just join the two signals together after that point, using a ¼" Y-connector, or do I need an electronic connection? I'll want dual ¼" input and single ¼" output...

[Nicholas Cox]

You could get an A/B/Y box and then you could switch between or use both with the click of a footswitch.

[Steve Lipsey]

Re A/B box...yes, of course...but I was hoping to avoid that extra switch by just connecting the two signals together...having to switch pickups on the guitar then being the only thing needed,

I originally was planning just to run in mono and turn the Aura on when I was using the Fishman (maybe still the easiest way)...having a stereo connection would allow setting up pedal chains and then just switching on the guitar and not having to hit an extra switch on the pedalboard...

And I don't know what effect the Aura would have on the Silver Foil signal...might that be OK to leave it on when using the Silver Foil? What might it do to the sound? (I don't actually have the new Road-o-phonic yet).

[Jeff Highland]

Are any of your effects Stereo? you could mix that way

[Bill McCloskey]

Why don’t you use a small mixer?

[Steve Lipsey]

No stereo effects. Still curious if I can just connect the outputs together....what will that cause?

[Nicholas Cox]

It would work but I believe there is some signal loss.

[D Schubert]

Wiring a magnetic and piezo pickup together as a simple Y is not a good idea. While each one sounds good separately, they do not blend well. Much better to keep the two signals separate (two jacks) and send each signal through its' own pre-amp or amp channel.

[Steve Lipsey]

Thanks for the tips, all!

[Fred Treece]

The comment about signal loss (volume) with this particular gadget is very accurate. Maybe there is a higher end version of the device, I don’t know.

An ABY switch can be set with both inputs on at once - no switching. ART makes a pretty good one.

The suggestion for the little mixer is another good choice, though I think you’d have a volume issue there too. Once you get the levels set for each channel you’ll probably have to crank your amp for all the clean headroom you can get out of it.

[Jeff Highland]

I'd try it with a Y Connector.
Connectiong a peizo and a magnetic together is not a good idea as D Schubert says, but once they have gone through the aura and the overdrive respectively they are buffered and may combine successfully

[Erv Niehaus]

[George Biner]

While hard-wiring them together with an adapter is possible and may sound OK, what's going to happen is one device will load the other in unpredictable ways, so one or both of them will probably end up sounding funky.

Get a small mixer to do it right, that will load each signal properly and keep them isolated.

[Georg Sørtun]

Plugging the aura and the overdrive directly together at their outputs, is the same as short-circuiting one unit with the other and is a bad idea. They may survive thanks to the minute power through those units' outputs, but they will be highly unbalanced in volume, and most likely also in frequency range because of the high load.

At a minimum a 10Kohm (1/4 or 1/8 Watt type) series resistor should be added for each of those "buffers" outputs, inside an Y connector or wherever it is practical. That will balance out loads and levels for those "buffers" and keep them safe.

[Steve Lipsey]

The Fishman Powerchip in the instrument provides automatic stereo or mono output for the Magnetic and Piezo pickups, depending on what kind of cord is plugged into it...I don't know how it combines the two outputs.

I have a call in to Fishman to see what they say - if it is simply a mechanical thing done in the jack or some electrical balancing thing done in the Powerchip...

https://www.fmicassets.com/Damroot/Orig ... _Guide.pdf

[D Schubert]

From the PowerChip description, it is designed to deal with the imbalance. Looks like you balance the pickups by adjustment inside the guitar, and can't change on the fly. And it requires internal batteries, which have always been a pain for me.

I have two resonators with double pickups. Both are biscuit-cone but the principle still applies:

Guitar A: Lace Slimline (magnetic) pickup at the neck, Schatten NR-2 (piezo) mounted on the bridge. Each pickup wired directly to its' own 1/4" jack. No batteries.

Guitar B: National Slimline (magnetic) pickup at the neck, wired to volume and tone pots, then to a 1/4" jack. Schatten NR-2 (piezo) mounted on the bridge, wired to a single volume pot, then to its' own 1/4" jack. No batteries.

On stage: HOSA stereo cord to two-channel amplifier, two separate amplifiers, two channels of a mini-mixer, or two separate direct boxes of house sound system.

[Bill Hatcher]

there are several small mixers out there... one is small enough to be on a pedal board that have the correct input impedance to see guitar pickups. you can input 2 or more guitars...eq them...sum them to one out if you like and turn each one on an it wont affect the sound of the others. when you hook two or more together through the same path with no separation to one out you are going to get some strange sounds. like when you have a double or triple neck and turn on one neck, then turn on two necks or three together....your sound for each neck by itself is out the window.

[Larry Dering]

I use this and it works great. 99.00 at Sweetwater and several others. You can balance your levels or boost, switch between them or have both on.

[Steve Lipsey]

thanks again, folks...when the roadie arrives, I'll have lots to try (will report back then)!

[Brett Lanier]

I sometimes play with a fellow who has a pretty complicated acoustic rig, and he uses this Grace instrument pre to control some of it from the stage. https://gracedesign.com/products/instru ... iers/felix

He plugs a 1/4" trs cable into his guitar. There's a Fishman Matrix pickup system on the "T", a Sunrise magnetic soundhole pickup on the "R", and then he can eq each of those independently with the Grace.

[Steve Lipsey]

OK...got the roadie.

I found these sources for an Active Combiner and a Stereo Cable:

Saturnworks Combiner, $74, gets great reviews. internal trimpot to equalize the sources:
https://www.etsy.com/listing/223374194/ ... r-combiner

Mogami custom-made stereo (and mono) cable, about $35
https://eventhorizon-srv.com/shop/mogam ... ble-p-5586

But when the Roadie came, I decided that I might want to feed both mag and piezo through the Aura, so I'm not (at least at present) going to split the signal into stereo.

I did modify the controls to make it easier to select mag/piezo/both by adding a pickup switch (see picture), as per the Fishman Powerchip manual (did have to mod the standard pickup switch to make it On-Off-On instead of On-On-On).

I put it in place of the mag tone control which, with the Lollar Silver Foil, just muddied up the tone....could add the tone back in by making the mag volume into a stacked volume/tone pot if I ever want to....

[Jack Hanson]

I know lotsa folks aren't crazy about these things, but they're economical, bulletproof, readily available, and serve my porpoises well:

[Steve Lipsey]

As people pointed out above, the passive combining boxes can mess with the signals by putting them into each other without some sort of active buffer in between....but sure, I've used those in the past...mostly to play one instrument at a time, not have both signals coming in together.

[Paul Seager]

For combining lap and pedal steel I favour the Boss LS2.its very versatile and one can usually find them on auctions quite cheaply. Another solution that I use and prefer for combining electric and upright bass is a Headway EDB-2. It's a preamp but has a good EQ that one may choose to assign to either or both channels. Not the cheapest solution but very high quality.

\paul

[Paul Seager]

sorry I omitted to mention why I would recommend the Headway as a specific solution to your problem: It has two channels, each with a switch to cater for line, instrument or piezo signals. Here is a link to the Headway site:

https://www.headwaymusicaudio.com/product/edb-2/

\paul