Adding a 2nd input to small practice amp

[nfway]

I would like to add a second input to a practice guitar amp that I have built, but have no idea where to begin.

I built an 8 watt practice amp using the LM383, which sounds great with my guitar. I have the input preamped using a LM741 (I know it's not the best choice, but it works well in this case), and would like to add an aux input so that I can plug my iPod MP3 player into the amp while still having my guitar plugged in. Doing this would allow me to play along with recordings of songs I am trying to learn.

Is this possible, or am I attempting something that cannot be done?

Thanks in advance for any help you might be able to offer.

N

 

[skyraider]

You can add in a mixer circuit in between your preamp and power amp.

 

[azira]

Make a duplicate of your 741 preamp network and then tie both of them into your power amplifier through some say 100-ohm resistors with a 10k volumn control. You'll also want to have a volumn control on each of the preamps so you can balance the levels between your input devices although you could probably get away without it. You're going to want to go to better devices though if you're fixing it up anyway...
--
Danny

 

[nfway]

is there any way of doing this with just the single preamp chip? I thought I could mix the two signals somehow before I sent them into the preamp.

I'm shying away from the dual preamp setup due to size constraints on my pcb, and would like to change as little as possible on the original amp circuit.

I guess what I am looking for is a mixing circuit, but have not been able to find any info on how to create one. Any tips?

Thanks again,
N

 

[nfway]

btw, the volume control of the iPod will be controlled directly on the iPod, so I do not need to add any adjustment for input levels on the amps itself.