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Reply To: H9 Jaco bass chorus

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brock wrote:

… not all of them pretty, but what a talent (and what a waste).  Anyway, you’re on the right track using the MOD DELAY algorithm.  I cobbled together a quick preset as a starting point.  It could use some complementary tweaking; depending on how prominent you want the effect to be.

By ‘complementary tweaking’, I mean parameter adjustments in multiples.  Like MOD DEPTH up + WET MIX down, or DELAY A/B up + MOD DEPTH / SPEED down.  There are so many ways to bring the effect forward, or push to the background.  If you have the luxury, you can set the H9 to WET/DRY, and split out to two amps, like I did here (and Jaco did).  Here’s my parameter breakdown:

  • WET MIX  –  50 is a good place to start.  Master control for the overall effect.
  • DELAY MIX  –  In mono, shifting to A10+B0 is a deeper effect, and A0+B10 is lighter.  I went with double DELAYs for the thickest animation.
  • DELAY A/B  –  25ms. & 13ms.  The 4th & 5th switch Delay Range on MXR Digital Delay rackmount, with a little Delay Time [x2 – /2] adjustment.  Just below a deep chorus with just above a deep flanger.
  • FEEDBACK A/B  –  Optional, but adds a subtle animation & thickening to the short delay times.
  • MOD SHAPE  –  SINE smoothes out the effect.  The ‘snap’ and ‘turn’ of PEAK & TRIANGLE are audible at higher depths.  The double waveforms are unique.  Useful for a lot of specialty stuff.
  • MOD DEPTH  –  Fairly wobbly at 12, but without the pitch-bending of higher values.
  • MOD SPEED  –  Seemed about right at 0.75 Hz, +/- another 0.25 Hz.  Higher MOD SPEED … lower MOD DEPTH, as a loose rule.  Try 0.50 Hz. – 2.00 Hz., and see what you like.
  • FILTER  –  These MXR Delay Ranges were allegedly full bandwidth to 20 kHz.  But it was 12-bit, and kind of noisy.  So I simulated that by darkening the FILTER.


At any rate, there are many ways to skin the proverbial gato here.  Here’s a minor variation, with the FILTER neutral, no FEEDBACK A/B, and the effect out in STEREO (normal routing).

The important change here is the MOD SHAPE.  It’s shifting the delays modulation 180 degrees out of phase.  The ‘chorus’ is going upwards, while the ‘flanger’ is headed downwards.  The dry signal is riding the middle.  Not as authentic, but very fat, with complex interactions.

Oh Brock wow thanks !
Top man, I have work do to now 🙂
I have got to consider the two amps route, would that be better than have the chorus in stereo… I suppose the ears will tell.