In general most under saddle piezo (or contact) pickups, in addition to most soundhole magnetic pickups will work well with the ToneWoodAmp. Any microphone-only or a "very microphonic" pickup will not work well with the ToneWoodAmp.

For best performance, It's essential to set and save the Master Gain (and if needed the Notch Filters) in the initial setup. Check the following videos:

Pickup designs vary, because of this and the way each pickup is installed; results will vary and produce different outcomes.

Generally, we have had a very good experience with most under-saddle piezo pickups, Expression II systems (Taylor)*, K&K Pure MINI*, and with most humbucking magnetic pickups. If the guitar is equipped with a pickup system that is a hybrid of a microphone + a piezo than the user should use (blend) more of the piezo and less of the mic portion.
Any microphone-only or a very "microphonic" pickup won't work well with the 
ToneWoodAmp, as it will cause immediate feedback. 

List of incompatible pickups:

  • LR Baggs Lyric: This is a microphone only pickup which would repeat the ToneWoodAmp signal, causing a feedback loop.

We recommend the: K&K Pure MINI and Expression 2 systems, as they sound great with the ToneWoodAmp (especially with reverb and delay). However, these specific pickups can be very sensitive to hi-gain effects such as the AutoWah and Overdrive. For these effects, we recommend you to read about  Using High Gain effects with Sensitive Pickups.

Related Articles:

Which Guitars Are Compatible With the ToneWoodAmp?