Doctor A FAQ

What are the available delay / reverb modes?

In v1.0:
4 delay modes: lofi, classic, spacey and ping pong
8 reverb modes: Small A, Medium A, Roomy, Bouncy, Plate, Vocal plate, Hall A, Concert Hall

Can I use both delay and reverb at the same time?

Sure, it’s designed for it.

What is the internal signal path?

The dry signal is kept analog from input to output.
It is converted to digital and sent to both effect’s inputs.
Delay and reverb effects are run in parallel, and a pot allows you to send the delay signal to the reverb input.

The DAC outputs only the wet stereo signal, and it is added to the dry signal in the analog domain.

Does it have a Kill Dry option?


Can I use it with my analog/digital mixing desk?

Yes, either as a stereo insert, or, by using the Kill Dry switches and the Dual Mono input option, you can send 2 mono Aux sends to Doctor A and get a stereo return of both effects to feed your desk.
As Doctor A can handle +19dBu signal levels, it is perfectly suited to this task.

What parameters can I control over MIDI?

From v1.1 firmware, all parameters can be controlled over MIDI.

What parameters can I control with the 2 CV inputs?

Both CV inputs can be used to control 1 delay or reverb parameter.
The assignable parameters are the 8 main parameters (the ones with the bigger knobs).

The CV inputs expect a 0 to 5V signal.
Its value is added to the target parameter’s potentiometer, so if you want full range control, set this pot to minimum value.
When the pot is set to maximum value, the CV input has no action.

Are the 2 CV inputs under and over voltage protected?

Yes, both inputs can handle standard eurorack levels (-12V to +12V) without damage.
Note that it’s always better to boost/attenuate CVs before sending them to Doctor A to get the higher possible resolution from your modulation source.

Can I store presets?

Doctor A was designed to be as “what you see is what you get” as possible, the 4 available memory slots are only a quick way to recall a specific delay + reverb combination, they do not store pot positions.

However, don’t worry if you need presets, (I know some of you rely on them for production or live acts), as the preset functionality will be added in a firmware update (in addition to those 4 quick recall memories), and there will be more than 4 available preset slots.

Is the firmware updatable?

Yes, it is, with the help of the MIDI SYSEX protocol (who said vintage?).

What are Doctor A’s voltage/current requirements?

9V (5.5/2.1 DC plug, center positive polarity), 250mA minimum.
Please note that we strongly recommend the use of the provided adapter.