I am researching a silent practice rig and I don't know if this is even possible. When practicing at home I use a Tech 21 Liverpool at the end of my signal chain (Guitar > Pedalboard> Liverpool>mixer). Is it possible to make a small mixer/headphone amp in a small Hammond 1290 or 1590 enclosure that I can blend my guitar signal, Mp3 player, and out to a headphone mix for silent playing. I don't need a cabinet simulator, just an amp to drive the headphone. I would like to power it via 9v batter or barrel plug.
I am a newbie, i've only built two pedals (Byoc Tremolo and 808), But I thought this would be a cool project to tackle.
Is this possible? Schematics? Pics available?
Theres a headphone amp project on generalguitargadgets http://www.generalguitargadgets.com/projects/15-boostersrouters/73-headphone-amp
Any of the LM386 based miniamp designs should have no problem driving a pair of headphones either.
For a mixer theres also a project on ggg http://www.generalguitargadgets.com/projects/15-boostersrouters/68-mini-mixer-project
But the topology in general is the same for almost all mixer circuits http://en.wikipedia.org/wiki/Operational_amplifier_applications#Summing_amplifier
The MXR amp is very similar to what I had in mind! Is there a way to wire an 3.5 mm jack for simultaneous use with the guitar input? Or would the mini mixer be better suited for this application?
the MXR Headphone Amp uses a non-inverting amplifier. ( the input signal is feeding to the (+) terminal of the op amp ) Most mixer circuits use inverting amplifiers ( the input signal is feeding the ( - ) terminal )
Here's an circuit from Electronic Projects for Musicians. PAIA still sells the kit minus enclosure. I'm not sure whether it would fit in a 1290 or 1590.
Practice Play Along Kit (http://www.paia.com/proddetail.asp?prod=CA-20&cat=14)