Audio amplification question

Hello.  I'm very new to electronics and have myself in an odd situation.
I'm trying to design a simple audio amplifier to drive a VU meter based on the 4739 dual opamp because I have a bunch of them.
I've attached a crude scheme below.




What's happening is I get an audio signal, but it's always unity gain regardless of the pot position.  I know the amplifier is working because my first version ran on a 9V battery and the output was weak and distorted.  When I switched to a +-12V power supply, the signal got stronger and clearer.  If I touch anything in the feedback loop, I hear the interference.  I tried reading about op amp design but from everything I've read, I should be getting 0-10x gain.

Like I said, I'm pretty clueless so any help will be much appreciated.

For an opamp to have gain, the negative feedback must be a portion of its output.
A voltage divider makes the portion of the output.

Correction: the inverting amplifier wil have an adjustable gain between 0 and 10.

Correction: the inverting amplifier wil have an adjustable gain between 0 and 10.

Of course. The pot could be adjusted to be a dead short.
I corrected the schematic:

In the modified circuit, the gain can be varied between 1 and 11 not 10.

You're not haveing a good day are you audioguru? ;D

Incidentally, there would be nothing wrong with being able to set the gain below 1 on an inverting amplifier.

Thanks for the quick replies everybody.
I actually tried running into the inverting input and got nothing out of it.  It didn't make sense to have a 1K resistor feeding into the non-inverting input but since I didn't get a signal, I tried it the way I showed in the scheme.  Perhaps my ground on the non-inverting input was poor.  I'll give it another shot.

Thanks again,  I was racking my brain yesterday over this.

The non-inverting input on the non-inverting amplifier circuit must have its input at 0VDC or the opamp will not work properly. The input can have a 100k resistor to 0V (ground) and a 0.1uF input coupling capacitor.

I have only 10 fingers so I can't count to a gain of 11. :-[

Well the inverting amp configuration works like a charm so I'm going with that.  My next challenge is adding a -10dB switch.  Any suggestions?  I was thinking a resistor to shunt part of the input signal to ground but I wouldn't know how to calculate it.

The input impedance of your inverting amplifier circuit is only 1k ohms. Many music sources cannot drive an impedance so low and need a minimum of 10k ohms for good bass response and low distortion. Then the pot should be 100k and the input resistor should be 10k.

This will be driven from a headphone amp which is designed for a 600 Ohm load.

So to switch this circuit to a .1X-1X gain, I need to put in a switchable L-pad in front of the 1K resistor?

You don't use an L-pad. Simply increase the value of the 1k input resistor to 100k.

That was my first idea but I thought the impedance change would alter the sound quality.  I guess it would be minimal since there's no caps before the opamp.