Need help; stereo in, mono out

[dewey decibel]

Hi, I've done all kinds of searches but I can't figure out what I need. I have a delay pedal with one dry output and one wet (so two mono outs), and I need to sum these to a single mono output. Is it as simple as wiring up a couple jacks with a summing mixer or do I need something with with a transformer or op amp? I found this:

http://www.aronnelson.com/gallery/main.php/v/familyortiz/2CH+COMBINER+STAGE+WITH+ADJ+GAIN.JPG.html?g2_imageViewsIndex=1

but am not sure if I need to take it that far. The delay pedal has a buffered output when bypassed btw. There's also something like this from Loopmaster:

http://www.loop-master.com/product_info.php?cPath=26&products_id=153

What do you think is in there and would it work for me?

My concerns are:
-I need the two signals to be of equal volume
-I don't want to add extra noise
-I'm worried about phase issues when combining the two signals
-I spent a lot of time/effort in preserving my signal through my pedalboard, this is the last thing in my chain and I don't want any degradation

Any help is appreciated!

[PRR]

You are fussy enough that you probably need mixer with make-up gain (otherwise two resistors and turn-up your amp two notches).

After a delay, "phase" is not an absolute thing. However you do get two different null-sets depending which polarity you pick.

I would assume your direct signal should pass in-phase unity-gain.

You have not said what power supply; designing for chip opamp and +/- power is easier for me.



If you ever play ONLY delay, break the wire from the 'direct' jack.

I am 99.44% sure this works.

[dewey decibel]

Awesome. Yeah, it would be 9v power (supplied by a Voodoo Labs PP2). Is there an op amp you'd recommend (be even better if I could get it at Radio Shack). I'm also not understanding how the polarity switch works. Is that an on/off?

[nexekho]

Just built it in Falstad, seems to work.  There is a volume difference when the delay is inverted, but I can't see any problems with it.

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[mth5044]

Out of curiosity, what is the delay pedal?

[dewey decibel]

It's a Malekko E600B. I bought it (in part) because I thought the delays would trail when bypassed in buffered mode, and they do but only with the wet only output. I emailed Malekko as I'd prefer to mod the pedal rather than use another box but they haven't gotten back to me.

[dewey decibel]

Bump for the answers to these questions...

Awesome. Yeah, it would be 9v power (supplied by a Voodoo Labs PP2). Is there an op amp you'd recommend (be even better if I could get it at Radio Shack). I'm also not understanding how the polarity switch works. Is that an on/off?