DIY kitchen speaker amp: analog volume control
 

My kitchen has a pair of wall-mounted speakers, but no amplifier. I wanted to play music on these with my iPhone and have a volume/power knob on the wall for control. I realize that there’s probably a better way to do this, but here’s the solution I came up with...
I got a dirt cheap amp on eBay for $20. It has a stereo analog pot for volume adjustment. I wanted to tuck the amp in one of the lower kitchen cabinets, away from view (because this amp is butt ugly!). Btw, I caught this line at the end of Sjef's post: "DO NOT BUY ANY CHINESE HIFI CRAP FROM EBAY> IT'S ALL CRAP". That made me smile, as it probably is the answer to my problem. :)


So I removed the stereo pot from the amp PCB. I soldered up a cable about 3 feet long, 6 conductors (2 channels, 3 pins per pot). You know where this is going right?

Yep, I did a sanity check and the audio was extremely static-y and popping. It’s like the chip amp was clipping or oscillating. I’m assuming that I built myself a great antenna, huh?

Any suggestions for what I’m trying to do? I just want volume adjustment up on the kitchen counter.

Use a wireless remote to control volume.

Yes, mount everything back as original, set (hidden) pot to some convenient midpoint and fine adjust the volume from your IPOD.
You are not mixing live like a DJ, just setting some background music, so no need to constant tweaking.
As an example: *now* I'm designing a PCB, want some background music but nothing too distracting, so I'm listening to some Classical Music using Shoutcast .
Set a background level and there it stays.

and if i may add my 2 cents, if it is dirt cheap stay away from that pot, they wear out so quickly.

Thanks for the replies, everyone!

A couple more thoughts --

In my case, I need to adjust the volume a lot. I have kids and they can be quite noisy. Also, if I'm listening to music, that requires one volume level, but podcasts can be very quiet in level, so I need to turn it up. So that's a lot of adjusting.

Also, I chose an iPhone dock connector which brings line level audio out (the preferred). Using the headphone amplified out level can really distort the audio to the speakers.

As JMFahey said, Connect the iPod to the amp with regular patch cables. Do all your volume tweaking from the kitchen counter control.

maybe a stupid question but is the cable run to the post shielded and grounded?