Two-channel mini-mixer

[unlockitall]

Hey everybody. I was looking into building this http://diystrat.blogspot.com/2008/08/two-channel-mini-mixer.html an I was wondering if you could tell me if it sounded good.

For parts I got:
3 mono jacks
10k ohm resistors
2 1megohm linear pots

Does this all sound right? I'm sure I messed something up, and it would be cool if you yell at me about it before I open stuff up and can't return it. Any help is greatly appreciated. Thanks.

[Jhouse]

I'm not sure if the size of the pots would have any effect at all (someone can feel correct me on this), but the schematic looks legit. I would probably opt for 10k Log pots though instead of those linear ones. It would make things easier to control in my personal opinion.

[unlockitall]

I didn't really know what the difference between logarithmic and linear was, and I didn't only saw the linear pots at radio shack. What kind of difference will this make?

[Jhouse]

R.G. Keen puts it so much better than I ever could. Read up on that bad boy.

[unlockitall]

So, if I've got this right, it will work with linear pots, but its gonna seem a little strange when adjusting the volume, right? I think I can live with this. Anything else seem off? Resistor values seem good and everything?

I'm also not sure what to do with the grounds...

[pazuzu]

the grounds all run together. preferably all to one point.

[unlockitall]

So, if I run a wire from each ground together, does that work? I feel like I'm supposed to make them go somewhere, and not have them together and floating in the air.
And, are mono jacks correct?

[Jhouse]

Just connect all of the points that are supposed to go to ground to one of the mono jack's sleeve.

[unlockitall]

Alright. Thank you.

[PRR]

Linear is fine here. You never want a LARGE reduction in volume.

The mis-match between guitar, pots, and mix-resistors is troubling. The original 10K pots are awful low for many guitars. Your 1Meg is a bit high, but the relatively much lower (100X!) 10K mix-resistors will give huge interaction.

You have the 1Meg pots in hand? Then blow the half-buck for a pack of 220K or 470K resistors for the mixing.

If you get new pots.... 250K would be a better value, with maybe 220K mix resistors. In a Radio Shed I'd look for 100K pots and 220K (or 150K) mix-resistors.

And before you get crazy: any "good" amp has TWO jecks per channel. Using one guitar, one is louder, the other is harder to overload. However if wired Fender-style (a LOT of amps copy the Fender jackery), then you feed one guitar into each jack and they are mixed equally. You can adjust relative volume at each guitar. This is how we worked back in the days when we had more players than amps.

[unlockitall]

Ok, I do have the 1 meg pots already. You're saying it will work with them, but I need either 220 k or 470 k resistors. Is one going to be a better choice?
And just as a side note, I'm actually going to use this for two mics so that my friend and I can record two guitars with a computer at the same time.

[unlockitall]

Just a follow up, I built it and used 100k resistors, because that was the closest to 220 I had, and it works. Yay.

[pedalcrazy]

I built this same 2 ch. mixer, but with 500k pots and tried everything from 47k to 100k resistors. Everything works, but when I adjust the volume of one of the pots it effects the level of the other channel. Ive triple checked that the pots are wired correctly and that its grounded properly (100k resistors do add a lot of buzz though).

I'm stumped. Its probably something really simple but I cant seem to get it right.

Any suggestions would be great!

[frequencycentral]

It's a passive mixer, always gonna be interaction. Stick a summing opamp at the end and you're rockin.

[pedalcrazy]

It's a passive mixer, always gonna be interaction. Stick a summing opamp at the end and you're rockin.

Thanks for the response!

Any recommendations as to what value resistors might work best with the 500k pots?