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Chase Bliss CBA PREAMP MKII MIDI CC chart, NRPN and OSC map

The Chase Bliss CBA PREAMP MKII MIDI implementation: 14 CC, each named, for Claude (MCP), SuperCollider or any OSC app.

Device Chase Bliss CBA PREAMP MKII
Vendor Chase Bliss
OSC prefix /cba_preamp_mkii
Source πŸŽ›οΈ Derived from an Electra One community preset
Revision per Electra preset
Upstream electra-preset
Driver file devices/chase-bliss/cba_preamp_mkii.json
Not tested on the device yet

This driver comes from documentation or community data and has not been checked on real hardware. If you own one, a quick test and a pull request promoting it helps everyone β€” see CONTRIBUTING.

How do you control it?

Find the MIDI ports, then start the bridge with this driver:

osc-bridge detect        # prints the ready-to-run line for what is plugged in
osc-bridge run --device devices/chase-bliss/cba_preamp_mkii.json --out-port <N> --in-port <M>

Then send OSC to 127.0.0.1:7777, for example:

osc-bridge osc-send /cba_preamp_mkii/volume 63

From Claude or any MCP client, the osc-bridge mcp server exposes this driver as cba_preamp_mkii: ask β€œwhat can the Chase Bliss CBA PREAMP MKII do?” and it reads this map with list_routes. See the MCP guide.

MIDI CC and NRPN parameters (14)

OSC address CC NRPN (MSB/LSB) Range Nature Section
/cba_preamp_mkii/volume 14 0–127 continuous
/cba_preamp_mkii/treble 15 0–127 continuous
/cba_preamp_mkii/mids 16 0–127 continuous
/cba_preamp_mkii/freq 17 0–127 continuous
/cba_preamp_mkii/bass 18 0–127 continuous
/cba_preamp_mkii/gain 19 0–127 continuous
/cba_preamp_mkii/expression 100 0–127 continuous
/cba_preamp_mkii/jump 22 0–127 continuous
/cba_preamp_mkii/mids 23 0–127 continuous
/cba_preamp_mkii/q 24 0–127 continuous
/cba_preamp_mkii/diode 25 0–127 continuous
/cba_preamp_mkii/fuzz 26 0–127 continuous
/cba_preamp_mkii/bypass 102 0–127 continuous
/cba_preamp_mkii/0 27 0–127 continuous

Performance MIDI

Notes, pitch bend and any CC are also available: /cba_preamp_mkii/note/on <note> <velocity>, /cba_preamp_mkii/cc/<number> <value>, /cba_preamp_mkii/pitchbend <0-16383>, /cba_preamp_mkii/program_change <n>.

Limitations

Imported from an Electra One community preset. The mapping reflects the preset author's editorial choices: parameter naming, ranges, and which params are exposed. Untested on hardware in this repo.

Frequently asked questions

How many parameters of the Chase Bliss CBA PREAMP MKII can be controlled over MIDI?

SynthHub's map of the Chase Bliss CBA PREAMP MKII lists 14 MIDI CC parameters, each with its number, range and a readable name; the full chart is on this page.

Can an AI agent like Claude control the Chase Bliss CBA PREAMP MKII?

Yes: SynthHub's hosted MCP server knows the Chase Bliss CBA PREAMP MKII's MIDI map, and its browser relay lets the agent send it parameter changes or load a sound, each sound change confirmed by you.