Author Topic: Anybody tried these digi potentiometers  (Read 2538 times)

Thewoodguy

Anybody tried these digi potentiometers
« on: December 29, 2015, 03:21:48 PM »
Any know about these digi pots? Seem like a good drop in replacement. I'm trying to learn how to make some of my pedals have digital control. It seem most don't like to use normal pots because of the noise and inconsistency. But these look pretty good to me (a knob haha)

What do you guys think


MetalGuy

Re: Anybody tried these digi potentiometers
« Reply #2 on: December 29, 2015, 03:54:11 PM »
I've used the quad channel AD5263 in the past. It worked OK for me. 10 bit resolution is way too much unless you're after some precision logarithmic pot or something.

Thewoodguy

Re: Anybody tried these digi potentiometers
« Reply #3 on: December 29, 2015, 04:00:40 PM »
Yeah I was thinking the same thing. I'm basically trying to make the mixer section of my Parallelyzer (parellel loop) to be able to have presets and midi. Any recommendations would be great.
http://www.generalguitargadgets.com/pdf/ggg_mixer_sc.pdf

Ice-9

Re: Anybody tried these digi potentiometers
« Reply #4 on: December 29, 2015, 05:12:36 PM »
I would personally select i2c non volatile digi pots over the spi versions, but that is just a preference.
www.stanleyfx.co.uk

It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

Thewoodguy

Re: Anybody tried these digi potentiometers
« Reply #5 on: December 29, 2015, 11:40:17 PM »
I would personally select i2c non volatile digi pots over the spi versions, but that is just a preference.

Thank you for saying that I just learned the difference of those. I'm definitely going to use a i2c. But is there differences in sound? What should I look for in a digital pot?  should I just replace the pots with digi pots and start programing? Or should I add to the curcuit to make it work better? Is 5v a limitation.

I feel like there is probably 100 of post here with an answer I'm looking for, but when I search it seems to be a bunch of people saying stay away from digi pots. Any help would be great

G. Hoffman

Re: Anybody tried these digi potentiometers
« Reply #6 on: January 02, 2016, 02:13:42 PM »
I would personally select i2c non volatile digi pots over the spi versions, but that is just a preference.

Thank you for saying that I just learned the difference of those. I'm definitely going to use a i2c. But is there differences in sound? What should I look for in a digital pot?  should I just replace the pots with digi pots and start programing? Or should I add to the curcuit to make it work better? Is 5v a limitation.

I feel like there is probably 100 of post here with an answer I'm looking for, but when I search it seems to be a bunch of people saying stay away from digi pots. Any help would be great

Digital pots have a habit of adding digital noise (high pitched squealing noise - not good!), so it is common to try to isolate them from the analog signal parts of the signal.  This can be achieved several ways, but probably the easiest is to use the digital pot to drive an opto-resistor in a voltage divider with a resistor, or two optos for both ends of the voltage divider.  (This is what I did for my MIDI remote volume control, and I'm not sure I needed both of the optos.  If I had it to do over, I'd try it with just one opto with a resistor.)


Gabriel

MetalGuy

Re: Anybody tried these digi potentiometers
« Reply #7 on: January 02, 2016, 04:23:05 PM »
There are "special" audio pots used in CD players for example so if you're after minimum influence from the digipot you should get one similar to those below although for guitar use it's kind of overkill:

http://www.profusionplc.com/types/volume%20controllers