Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

Doctor Click

Rhythm Controller

Interfacing instruments and equipment in the electro-music studio will always be a time-consuming necessity for most composers and The Doctor Click offers many solutions in one well-researched package. Whether or not it seems totally 'over the top' for you personally does not really matter, because its interfacing functions should be of interest to anyone trying to utilize their studio to the fullest extent.

Doctor Click is unique in that it enables synchronization and triggering of sequencers and drum machines, as well as modulation control for VCO, VCF and VCA sections of synthesizers. Although specific sync codes from several major manufacturers are catered for, the unit comes into its own in handling most trigger interfacing situations - it can read or build click tracks, including reading live and electronic drum tracks.


Doctor Click is an American product from Garfield Electronics and is truly professional in its finish and internal design. The instrument is obviously built to last, with strong metal case, good quality micro switches (with built-in red LEDs), mechanical 3-digit Tempo adjustment and non-standard rotary knobs.

Looking at the control panel, there are four main sections across the top: Channel 1 and Channel 2, each offering their own trigger and envelope output options, an Input section, and a built-in Metronome. Channel 2 also has a socket that gives a variable level 'click' in a pair of headphones. In this way it provides a low impedance stereo signal for initial monitoring, but is more likely to be used for sending the clock rate selected on Channel 2 as a tape click track (including cleaning up a distorted track, or one derived from any pulse or sync code input).

On the front of the unit are Memory and Record function buttons alongside the phones socket and at the rear are 13 different levels of outputs, 4 input types, 3 external footswitch sockets, power switch and Delay Amount control.

There are 5 'fixed' clock outputs: Time-base 96X is for Oberheim DMX and DSX, 48X/PGM is for Linn LM-1, LinnDrum, and Roland MC-4, 24X is for step programming, and 12X is for Roland CR68, CR78 and other step programming machines. The fifth output is for a 5 pin DIN 'Sync Out' socket for Roland and Korg units.

One or more of the Timebase outputs are connected to your sequencer/drum machine and sent when Doctor Click is switched to 'Play' mode. When in 'Reset' mode all outputs are grounded but the 48X/PGM output can be used for additional step and Autoprogramming functions. Rear socket Metronome and Trigger outputs are always active and the Time Lag Out socket remains at 5 Volts.

Channels 1 & 2

Both channels have identical Envelope control voltage generator sections. Channel 1 has 8 Timebase selection buttons: 1, 2, 3, 4, 5, 6, 8, 12 and 24; multiplying the selected number by the particular timebase output socket(s) in use gives the actual clock rate - related to the internal metronome clock speed set, or to an external clock pulse from various 'drive' options to be discussed. Timebase 96 requires 96 clock pulses to play a quarter notes worth of music in 4/4, 3/4 or 5/4. Timebase 12 is most suitable for step programming as all basic note divisions can be made.

Beneath these numbers on the panel is a second row of numbers indicating the 'notation' interpretation: 4 = quarter note, 8T = eighth note triplet. So the numbers are 4, 8, 8T, 16, 16T, 32, 32T and 64T. A third row is also operative when switched to Low Range for Channel 1 only: 4M, 2M, 2MT, 1, 1T, 2, 2T, and 4T, where 1 = whole note and 2MT = 2 bar measure triplet.

Channel 2 only has the first 6 buttons as in Channel 1. In addition, Channel 1 also produces a pulsewidth variable Gate Out (5 or 15V), Time Lag Out (this is a falling edge version of Gate Out that is useful for slow attack envelopes e.g. Sleigh Bells), and Auto-Programming functions.


Channel 1 and 2 Envelope sections are ideal for any modular synth system that has external control inputs for VCO, VCF and VCA. Any two of these parameters (or other suitable CV inputs) can be controlled together, synchronised to the particular clock control in use.

Controls for Attack time, Delay time and CV Amount (adjusting CV envelope range) set up precise 'AR' type envelopes. An Invert button offsets the selected clock pulse by one half of its value, so that a quarter note rhythm would still produce quarter notes, but as the 'upbeat' eighths. The CV Amount control will give 0-13 volts for VCF or VCA for both Channels, while Channel 2 Env 2 output will also give 0-2 volt range depending on a half or full insertion of its jack plug, the latter range is obviously more suitable for VCO modulation.

Really complex waveforms can be made by directly combining Env 1 & 2 CV outputs and if you want to create Jean-Michael Jarre's Magnetic Fields correctly you could use a different synth on each channel with one in Invert mode for 'delayed stereo' effect. A surprising number of control envelopes are possible from the provision of a pulse width control on each channel as well. Fixed DC output voltages are also available.

Doctor Click's rear.

Extra functions

Two other outputs at the rear are 'Trigger Out' and 'Start Out'. The 'Trigger Out' pulse is set up with the Gain, Threshold, Mask and Fine Controls and will convert any audio or pulsed signal (e.g. a drum part on tape) to a sequence of synthesizer triggers. Suggestions are provided for overcoming any micro-processor related delays in timing. Doctor Click has its own internal delay unit for fine tuning studio delay times (rising or falling edge outputs help with Emulators and Synclaviers). Start Out is normally at ground and goes to 5V with Doctor Click in Play Mode, (important for machines like Roland CR68 and CR78).

The built-in Metronome can set a 'master clock' tempo in beats per minute or frames per beat using the 3-digit thumbwheel switches. Unusual values, including fractional tempos, are all easily obtained. The frame count is, of course, for film makers and the Metronome output's precision is due to a crystal-controlled clock.

Drive Options

The Pulse In socket is for any click track, electronic drum, live drummer or built click track and by means of Gain, Threshold and Mask controls can set up numerous clock control variations. The Mask control is really a monostable adjustment that adds a delay before the pulse appears (at Trigger Out) - it's useful for missing out pulses or setting cross-rhythms. (You'll find this facility on E&MM's trigger Interface project (July '82)). The controls do make life much easier when it comes to taking virtually any click track source as control, say, from someone else's taped track.

Resetting (i.e. stopping the clock pulse train) can be immediate or on the next pulse. There are 3 modes of pulse driven operations: Real Time, Memory Record and Memory Playback. Sockets at the rear also allow Sync Code drive from Oberheim, Linn and Roland microcomposers.


The memory function allows triggerable instruments to sync to the varying tempos of a live drummer or an already prepared click track. With live drummer sounds feeding into Doctor Click, the procedure works best by putting bass drum and snare lines as a 'guide track' on tape, so that missing beats can be pulsed in using the 'step' switch. This guide track is then sent to Doctor Click in Record mode and a final tidied track is then overdubbed onto tape in Play mode.


Step programming is made easy by selecting Timebase 12 and using the Step button to enter the correct step count for each note, e.g. Minim = 24, Crotchet = 12, Quaver = 6, etc, whilst Doctor Click is in Reset mode.

Autoprogramming is an extra function from the 48X Timebase socket and lets you enter steps in groups according to the selection button pressed in Channel 1. So real time playing of the keys on a synth sequencer is done in its Record mode, followed by pressing the Step button for the correct steps, another chord, and so on.

Footswitch inputs for Play, Reset and Enter all help to do the job.


At around £1400, the Doctor Click is quite an expensive proposition, yet its interfacing potential is better than anything else available commercially at the present time. Plenty of information is provided for specific linking to many current instruments and by trial and error you can usually find an answer for others not listed.

If Doctor Click has the answer to your problems, you will find that he is waiting for you at Syco Systems, (Contact Details)

Previous Article in this issue

Seiko Digital Keyboards

Next article in this issue

Industry Profile - Moog Music

Electronics & Music Maker - Copyright: Music Maker Publications (UK), Future Publishing.


Electronics & Music Maker - Nov 1983

Donated & scanned by: Stewart Lawler

Gear in this article:

Synchroniser > Garfield Electronics > Doctor Click


Previous article in this issue:

> Seiko Digital Keyboards

Next article in this issue:

> Industry Profile - Moog Musi...

Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Donations for December 2021
Issues donated this month: 0

New issues that have been donated or scanned for us this month.

Funds donated this month: £4.00

All donations and support are gratefully appreciated - thank you.

If you're enjoying the site, please consider supporting me to help build this archive...

...with a one time Donation, or a recurring Donation of just £2 a month. It really helps - thank you!

Small Print

Terms of usePrivacy