Audiosector kit: adding a pot

[gongzero]

Funny thing is that in the overall parts list, these pots are right up there in the unit cost scale and I'm buying on the cheap end...Precision pots through Digikey...some pay a lot more for Alps and Noble and others.

I've been looking for the part number and have come up with this one:

http://ca.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=288642&Row=516895&Site=CA

Not sure if 'dual' means it's dual-channel though.

Can someone help a n00b out?


-A

 

[CarlosT]

I'm using a simpler single element which means that it controls just one input. In my case, I'm combining stereo channels through 10K ohm resistors right before coming into the sinlg element pot.

If you're designing a stereo amp though you prolly need a dual element pot like the one you picked out.

I'm a totally green noob, too...good luck

The part number is RV4N253C-ND

http://www.precisionelectronics.com/MIL Style RV4 PDF Download_files/MIL Style RV4.pdf

 

[gongzero]

Thanks for that info!

Yes, I'm working on a dual-mono design using one paralleled LM4780 per channel, driving 6-ohm speakers -- all using on Peter Daniel's PCBs. I'm still uncertain as to whether or not I want it to be strictly a power amplifier.

I've also got some LM4766 samples to play around with, though, so I'm mostly just poking around for general info as applicable to whatever thought I'm entertaining at any given moment.


-A

 

[CarlosT]

I'm trying to see if I can build this stuff before Xmas to be incorporated into an also yet to be built retro cabinet with a single 4 ohm Audax full-range driver. It's for the kids to plug in their iPod and isten to something decent I hope. The working man "docking" iPod stuff out there is pretty pathetic.

This is all adding up $$$ but hey...it's for the kids

 

[CarlosT]

Those issues have been pretty well explained here: http://www.diyaudio.com/forums/showthread.php?postid=164564#post164564

Peter:
Now that I'm revisiting this, it appears that the original Thorsten IGC had a pot right in the feedback loop. I can't tell because obviously Joe's posts are ancient and the pic links are no good. I just inferred this from reading the text.

This is not what I was struggling with though. The pot I was thinking would go in the usual position...in line with the input.

 

[Peter Daniel]

Here's the Thosrsten's schematic that started it all: http://jwg.student.utwente.nl/fedde/audio/images/invertedLM3875.gif
Joe's posts have been based on that too.

 

[flraer]

I'm about to adding a pot too my lm4780 audiosector kit and have a couple of questions about grounding.

I know there are a lot of threads about this but i can't figure out how to do.

Does this picture look god? Or have i got it all wrong?

http://img96.imageshack.us/my.php?image=schemagh9.jpg

An externally hosted image should be here but it was not working when we last tested it.