C|24 (Curtis)

I. Project Summary

I owned the mechanical engineering and industrial-design implementation of Digidesign’s C|24, from the early surface and packaging work through tooling, build support and production release. The job was to turn a large, familiar control surface into a lower-profile product while preserving the feel and accessibility of a real mixing console.

The business brief was specific: replace the Control|24 with a RoHS-compliant product, package sixteen Digidesign preamps in place of the licensed design, support 5.1 monitoring, and fit within a 43-inch maximum width. Removing the approximately $200 royalty was a program objective. My responsibility was the physical product that made those changes possible: surfaces, molded parts, fabricated chassis, board interfaces, controls, artwork and the instructions suppliers needed to build and inspect them.

II. The Product That Shipped

The C|24 put twenty-four motorized faders, sixteen preamps, a stereo submixer and surround-monitor controls into one low-profile console. Most analog connections moved to DB25 connectors. Three two-row LCDs replaced the predecessor’s short channel readouts, and the control layout consolidated functions that had occupied dedicated buttons. The product and hardware teams defined the feature set; I developed and integrated its physical implementation.

That integration reached below the visible surface. The March 2006 construction-review email records my solution for getting the meter boards inside the sheet-metal enclosure while preserving the plastic design I wanted. Once that packaging problem was resolved, I redirected the review time toward releasing the Data Control Drawings that the PCB designers needed. Surface development and electrical packaging advanced together.

I also designed and built the new two-encoder surround-panning interface: an X/Y control that let an engineer position a sound across a 5.1 field by feel. The side caps, gills, meter windows, jog-wheel surround and front bolster gave that dense control layout a continuous exterior. Their appearance depended on the geometry and assembly underneath them.

III. Design and Production

1. Paint Curing and Side-Cap Fit

The long ABS side caps exposed the interaction between molding, paint curing and assembly fit. Jetcrown’s comparison shows the original unsupported baking arrangement, an attempted three-support fixture that still allowed twisting, and Method A, which held the parts vertically to reduce deformation. I worked the problem through the supplier’s process and the mating geometry.

The July 5 inspection table shows why the diagnosis mattered. One left-side-cap sample lost 1.04 mm in length through painting, from 755.28 to 754.24 mm, ending 2.27 mm below the lower drawing limit. The same inspection tracked flatness separately. Cure support could address deformation, while the part’s final size and mating geometry still needed their own decisions.

I released the plastics for production through ECO 12740, including mechanical changes to both side caps. Supplier process work continued alongside the part revisions. Getting the plastics into production also required agreement on which dimensions controlled fit and which could be relaxed.

2. Recovering Top-Panel Fabrication

The main panel combined large fabricated surfaces with densely placed welded hardware. By March 7, 2007, the status report recorded Kwanta’s no-bid and an active Operations and Manufacturing response. The April report identified Mass Precision and Kenny as bridge options within the VTech manufacturing program.

I worked with Mass Precision on manual offset-welded parts and supported the overseas fabrication path while welding capability and panel quality were being resolved. The geometry still had to work at the factory: access for the welding head, placement of the studs, countersinks, bend quality and the cosmetic surface all belonged to the same part.

I fully ruptured my Achilles during this period. After returning from the hospital, I sent the weld-stud files from the hotel so fabrication could continue. The work progressed, but the later lessons-learned report also records the cost of working outside the normal file-control system: an incongruent revision reached the manufacturer.

3. A Quiet, Low-Profile Console

The C|24 requirements explicitly prohibited a fan because the console sits at the mix engineer’s listening position. They also specified an external power supply, replacing the Control|24’s internal supply. Moving power conversion outside the console and consolidating the rear-panel connections helped make the lower-profile enclosure possible.

The specified operating environment was 10–35 °C. Cooling and packaging had to work within that requirement while keeping the listening position quiet.

4. A Field-Replaceable Headphone Jack

The proposed front jack location put the headphone plug where it could be struck, while the original assembly made replacement unnecessarily invasive. Arndt Hufenbach and Manufacturing pushed for service access, and I developed the mechanical response.

The first recessed-bolster mock-up did not settle the matter. In April, product management rejected it because different headphone-plug overmolds made the recess awkward to use. Several PMs remained strongly opposed to a replaceable jack. Arndt, Manufacturing and I continued pressing the issue, and I designed the field-replaceable unit that ultimately shipped.

The July mounting-change form and the earlier rejected mock-up describe different stages of that work. The engineering lesson is the negotiation between access, protection, appearance and serviceability, carried through to a physical solution.

5. Board-to-Mechanical Interfaces

I controlled C|24 board interfaces through Data Control Drawings. The June register lists 19 distinct PCBA designs; the MicPre8 I/O drawing records 12 revisions.

I used Data Control Drawings to make those interfaces explicit: board outlines, mounting holes, component locations and clearances that electrical layout had to respect. The MicPre8 I/O drawing reached revision 12. Its revision table records changes to mounting holes, headers, connector spacing and the board outline, with my name against the revisions. The point was to resolve those changes against the assembly while the design was still editable.

The drawing releases gave PCB layout and mechanical tooling a common set of interfaces as both designs evolved.

6. Power-Supply Certification

The external supply created a separate release dependency. The July status report planned to hand-pack the first hundred supplies and apply UL labels at Menlo Park, while a later enclosure variant remained subject to thermal work.

Engineering worked with UL to start system and supply certification in parallel. The post-project lessons identify that as a successful change to the NPI process. Mechanical release, hardware validation, certification and the final pack-out had to converge for shipment.

7. Controls and Molded-Part Geometry

The smaller Bourns EM14 encoder needed its own mechanical integration. I designed the jog-wheel support and surround so the component, knob and adjacent surface worked as an assembly. ECO 13082 records the bracket release. ECO 13526 later relaxes its mounting-hole tolerance to ±0.05 mm at the vendor’s request, making the drawing compatible with the fabrication process.

The gills required careful surface development and dimensional inspection against the side caps. The molded parts also brought short shots, drag, sinks, gate placement and interference around the faders. The June issue list separates completed corrections from open questions and temporary trim-to-fit measures. In sustaining work, I also supported foam sealing around the meter-lens area to address dust ingress.

IV. Production Acceptance and Release

I carried the mechanical model through supplier files, drawing releases, inspection and assembly feedback. The record includes the plastics and artwork, the sheet-metal structure, small controls and light-management parts, and the changes needed after those pieces met on the line. The work extended into sustaining changes after First Customer Ship.

Inspection criteria were part of that engineering responsibility. In November I originated deviation DEV00118 to remove noncritical dimensions and increase selected tolerances, with acceptance tied to named Jetcrown inspection reports. It covered side caps, the bolster, meter parts and gills. The decision preserved what controlled fit and function and made acceptable production variation explicit.

The lessons-learned record is candid about the broader launch. It credits meeting Q4 FQA and revenue targets and getting costs below the Phase 1 target. It also records revision confusion, late board changes, cosmetic quality problems and inadequate spare-parts coverage. Mechanical control had to include the files, the supplier’s understanding and the inspection decision, as well as the CAD.

V. Results

• Product mandate: twenty-four faders, sixteen preamps and a 43-inch maximum width; removal of the approximately $200 licensed-design royalty.
• Mechanical integration: nineteen distinct PCBA designs in the June build register; twelve documented revisions of the MicPre8 I/O drawing.
• Serviceability: a field-replaceable headphone-jack assembly, developed despite resistance to changing the original design.
• Manufacturing: a manual-fabrication bridge, documented cure-support alternatives and explicit acceptance criteria for production plastics.
• Delivery: First Customer Ship on November 7, 2007. The project retrospective records that the Q4 FQA and revenue targets were achieved.

The July financial plan estimated a 51.8% gross margin at an $8,995 suggested retail price. The later product-master approval set the price at $9,995.

VI. Market Context & Legacy

The C|24 offered a substantial physical console below the ICON range: twenty-four faders, audio front-end functions and monitor control in one product. Kevin Becka’s February 2008 field test connects the external power supply and DB25 conversion to the lower-profile design, and describes using the two-encoder surround panner. His review also records real tradeoffs, including LCD viewing angle and the loss of a dedicated numeric keypad. Mix field test.

The hardware had a long supported life. Avid lists final sale on December 31, 2017 and end of support on December 31, 2022. Neyrinck’s current documentation describes third-party C|24 support through V-Control Pro, extending its software options beyond Avid’s product cycle. Avid lifecycle record, V-Control Pro documentation.

VII. Source Trail

The engineering account draws on the Curtis hardware PDD, the June PCBA build register, original project emails, drawing revision tables, vendor inspection and fixture records, ECOs, the November delivery schedule and the post-project lessons learned. The manufacturing photographs below show the actual parts and their interfaces. The economic figures retain the dates and assumptions of their source snapshots.