Here is the new delay pedal for vocals/studio with balanced XLR inputs, adapted for use with any 9V adapter with a maximum of 2A.
 
The Maestro-tron uses a hybrid digital/analog signal processing technique, unbalanced signal processing, and analog processing, but generates the repeats with a digital clock using the PT2399 chip.
 
The Maestro-tron has four controls and a red button:
 
 
The Gain control controls the overall gain of the device.
The Repeats control controls the number of delay repeats.
The Time control controls the space between repeats, from about 30ms to a little over 750ms.
The echo volume is a mixer between the dry signal and the delayed signal.
The red button is a momentary actuator to generate infinite repeats and allow you to loop your favorite sound while holding it down.
Be careful with your ears, the Maestro-tron has quite a lot of gain and the infinite repeat actuator can cause too much unnecessary feedback.