I am trying to use my Werkstatt with headphones, but I can’t seem to control the volume. Is there a way to raise and lower the volume for headphone use?

There is no volume control on the Werkstatt, so you may want to run the instrument into a mixer or other device. Since the Werkstatt was designed to be a highly mod-able synth, volume control is one of the many modifications you can perform. 

Please visit werkstattworkshop.com for details on this modification, and many others.