I was wondering if I could power my Fernandes Dragonfly Pro sustainer with a standard DC power adapter. I have a box full of 9vdc adapters. I chose a "center-pin-negative" power adapter from my box and tested the voltage and verified polarity.
I cut the connector from the power adapter. I happened to have a spare battery connector sitting around which I used for this test. Using the following diagram, I soldered the connections, taped the bare connections so they wouldn't short together or against anything else.
To test the adapter, I snapped the battery connectors together (neg to pos and pos to neg) which reverses the polarity, and plugged the instrument cable in to the guitar's output jack. The LED lit up nice and bright, so I braved turning the amp on... After the tube filiments heated up, I was pleasantly surprised that my Fernandes Dragonfly Pro was operating perfectly on the new 9vdc power adapter. No more changing batteries in my guitar!
I plan to experiment with cable lengths, and to go through a discovery process to determine if any buzzing or hum could be induced into the system as a result of this Fernandes Dragonfly Pro Sustainer power mod! Stay tuned!