Pan Pot Problems

[djgout]

Hi

I'm having some trouble getting an unbalanced pan pot to fully put the signal on one side or the other. I've tried a few different values, 10K, 50k, 100k, 500k, and 1M all linear, but they still aren't pulling the signal totally to one side. The 1M is getting the closest but then by the time I'm at center the level loss is far to drastic. So far the 50K feels the most natural. Is there anyway that I can add some resistance without changing the feel of the pan so drastically? I know that on some Neve modules they have some resistors attatched to the actual pot. What is this doing? I had just assumed it was to change the taper slightly, but I really don't know.

Right now the Input to the pot is connected to the center lug with the right and left outputs on the right and left lugs. I've tried to use a dual gang pot with the inputs tied together and the grounds tied but it was constantly sending too much of the signal to ground.

Any suggestions?

thanks

 

[solder_city]

the problem is your circuit is wack. thats not a panpot and it wont work the way you want. neither will the other circuit you described. instead of me spelling it out for you, look around at some known panpot circuits from real mixers and youll catch on pretty fast.

 

[Kit]

Yes, that wont work.

Check this out.....

http://www.groupdiy.com/index.php?topic=3816&highlight=pan+pot

IMHO a dual-gang pot makes for the best panner.

 

[pstamler]

I still like the Orban circuit. It's like a sideways "H"; from the input you send two resistors to the two ends of a linear pot; the wiper of the pot is grounded. The two ends also send resistors to an active summing circuit, or are connected to buffers with an input load resistor.

All of the resistors are 1.4 x the value of the panpot. So for a 10k pot you'd have 14k resistors, including the summing resistors for the active stage or the load resistors for the buffer.

Total loss with the pot turned for full on in one channel is about 10dB.

Peace,
Paul

 

[12afael]

check this geofex article .
http://www.geofex.com/Article_Folders/panner.pdf

 

[Freq Band]

This was also linked on the other thread, but again:
http://www.benchmarkmedia.com/pdf/panpot.pdf

=FB=

 

[djgout]

Thanks for the links guys! Got it figured out and realized why my original try with the dual gang wasn't working. Initially I had the input on the wiper, and the inputs were tied together......so basically everywhere on the throw I was just sending the plus to ground pretty evenly, so no wonder it wasn't really working.
I tried the *orban* circuit but it would be way too much loss overall for all the channels.

So it's basically new york dave's design with a 10K dual gang, 5.1k parallel resistors on the pot itself, 10K summing, and no input resistor into the pot because the impedence was only 130 ohm.

thanks again

 

[NewYorkDave]

If you omitted the series input resistor, it's no longer "my" panpot... It's just a conventional dual-gang type. And in the case of 10K mix resistors, the "slugging" resistors should be 2.2k instead of 5.1k. Otherwise, you won't get the correct panning law.

The conventional dual type has low loss and decent law but the input impedance is all over the place, which can cause problems unless the source impedance is very low. My version has a minimum loss of 6dB, but a more constant input impedance and a closer adherence to correct constant-power law.