VO

Whether you're trying to make sure your synth is actually in tune, or you're trying to create a sequence and you're not sure what note the current step is set to, this ultra-slim 2HP tuner module can help. It's unique in that it has two different ways of detecting pitch:

Frequency

In this mode, VO works like your typical tuner. Connect the output of your oscillator to the tuner's input and it shows you the nearest note (and how far off you are from it).

Voltage

In voltage mode, VO works similarly to a standard voltmeter, except there are 12 divisions per volt instead of 10. Connect your control voltage to the tuner's input and it displays the note that should be coming from your oscillator.

Of course, whichever mode you use, the module offers a buffered thru jack so your signal can continue on its way uninterrupted.