Forgive us while we focus on our Kurzweil K2500/K2600 users for today’s Tech Tip. We’ll get back to more universal issues tomorrow. Thanks to Jean Bellefeuille of Kurzweil for his input!
An important element in much contemporary music is the ability to modulate sound parameters in tempo with the song. Here’s how to sync an LFO within a K2500/K2600 program to an external MIDI clock. Remember you have to set the Clock parameter in the Kurzweil’s Song Mode MISC page to EXT to allow the LFO to follow external sync.
If you have a K2500 with version 4 or later of the operating system or a K2600, you have a new control source called Tempo. This control source can use the K2500’s own internal clock or an external clock (depending on the setting of the Clock parameter on the Song Mode MISC page).
To sync LFOs to a sequencer clock, choose your program and press “Edit.” Push the LFO soft button and then highlight the “RateCt” (rate control) field. Set the rate control to “Tempo.” Then you can select the note value you want to follow by adjusting the LFO’s Max Rate and Min Rate values, following this guide:
Eighth notes: Set the LFO Max Rate to 8.00Hz and the Min Rate to 8.0/64 (which equals .125Hz). The closest value available on the Kurz is .12Hz.
Quarter notes: Set the LFO Max Rate to 4.00Hz; set the Min Rate to 4.0/64 (or .0625Hz). The closest value available is .06Hz.
Sixteenth notes: Set the LFO Max Rate to 16.00Hz and the Min Rate to 16.0/64 or .25Hz.
To explain this concept: you divide the Max Rate by 2, a total of six times (or 64), because the tempo control source covers six doublings of tempo, from 3.75BPM to 240BPM. The Max Rate corresponds to the LFO rate when the tempo equals 240BPM.
Once that is done you can continue to edit the program and assign the LFO to any given Source field, depending on the effect you want. For example you may insert an LFO on the F4 AMP page of a program’s layer to create a tremolo.