On the control side, it’s hard to beat an expression pedal (or two). Multiple parameter mapping, different directions, saved per-preset, etc. There’s also somewhat of a gray-grey area developing now; landing somewhere between expression & MIDI control [Source Audio Hot Hand or Reflex; EHX 8 Step Program; Molten Voltage products; Doepfer Pocket & Wheel Electronic; et. al.]
MIDI control is the ultimate, especially with sync’ing two or more H9’s and/or the rest of the system. It can be as simple or as complex as you’d like. But be forewarned: it has it’s own learning curve, and can take you down a rabbit hole that never ends.
On the audio side, stereo. The H9 algorithms reach full potential with multiple amps. Guitar amps, wet/dry configs, FRFR … each have their own unique flavors and uses. As always, invest the time for proper gain-staging. And then there’s something that you’ll rarely see: route the two H9’s in parallel.
Split any mono signal upstream, out to each H9. Run the respective ‘left’ & ‘right’ outputs in each H9 to a 4+ channel mixer. Bonus points for a separate dry path, and the H9’s at 100% wet. There are *glorious* effects to be had outside of the serial path mindset, and fine control over every individual aspect of the sound.
Here’s the best tip I can give that won’t cost anything (additional): Treat two H9’s in series as a single, complex unit. One massive ‘algorithm’; spread between two hardware modules. Quite similar to building your own algorithms – a Gestalt whole, greater than it’s constituent parts. Use an algorithm in the 1st H9 that you might not normally consider compatible with the 2nd unit. For example, pitch shifters in one H9, followed by a panning tremolo in the next. Or a compressor in one, to shape the reverb envelope in the next.
Now, if you mean additional effects pedals that complement your two H9’s … A Maxed-Out H9 can do most any effect. An H9 Max + H9 Core can do most any effect, in two different places. But if – for example – you’ve already split up delay and reverb, and want a separate modulation effect … I used to use an AdrenaLinn III in series, for the unique FX found within it, and as a ‘catch-all’ for any additional effects. Now, I’m down to separate compression, distortion, freeze, 2-3 pitch-shifting units, and a looper. While I can do most any of that in the 2 H9’s, these are the effects that I use most often. And it leaves the H9’s open to cover the rest.
