Spark Amp Line Out Mod - Stereo

thingiverse

Schematic provided. There is a 3D printed router template (that I forgot to take a pic of installed) that you can screw into place first on the external panel and use a 1/4" router bit with a bearing to trim the hole for the line out mod. The 10ohm and 100nF cap can be soldered in series, a little heat shrink, and it soldered in place across the XLR pins. It is there to squash AM radio stations from coupling onto your long cables so the wattage of the 10ohm does not matter. The 10uF is soldered in series with each input channel and strain reliefed with some tie wraps. If you install this in the center of the amp the bass reflex tube will need to be trimmed back. A hole is drill right in front of the speaker cables to pass the line out cable into the speaker cabinet. A little hot glue can be used to seal the hole. Switch, transformer, and XLR are taken from 2 - Behringer Ultra-DI DI400 for stereo out. Line out with have the guitar and any bluetooth, USB, or line in signals down mixed. Headphone and Speakers still work as designed. Level out is effected by the Output knob. Worked perfectly this past Sunday outside as a personal monitor and the line out driving a mixing board and PA. Added a Single Channel option if you just want to pick off left or right for intent of using it just for your guitar out. Keep in mind that any aux audio ins may be missing parts / sounds if you are only using a left or right channel and it is a true stereo mix that is playing.