Manufacturing Guides for Audio Products
34 guides on getting parts made for hi-fi, written for the person who designed the product and now has to get it built without it coming back looking wrong.
Four sections
Every guide sits in one of these. Four are written for the person buying the parts and one is written for the shops that make them. Start at the section that matches the problem in front of you.
- Chassis
10 guidesAudio Chassis Manufacturing: The Whole Picture
An enclosure is three or four parts made by different processes that have to end up looking like one object. This section covers how each part is made, what it costs and where those two things fight each other.
- Finishing
8 guidesFinishing Audio Parts: Anodize, Brush and Blast
A faceplate is judged on its surface before anyone reads a spec sheet. This section is about controlling that surface, and about the fact that most of it is decided long before the part reaches the anodizing tank.
- Parts
6 guidesKnobs, Platters, Cups and Feet
These are the parts people pick up, turn and look at closely. They are small, which makes every cosmetic requirement harder, and they almost always come in matched sets.
- Sourcing
6 guidesSourcing and Quality Control for Audio Parts
Machining a front panel is not difficult. Making the same front panel again in a year, to the same appearance, is the whole job. This section is about buying that rather than buying a price.
- For shops
4 guidesGuides for Machine Shops Taking Cosmetic Work
The other half of this business. These are written for the shop owner rather than the buyer, because a match only works when both sides understand what the job actually costs.
How these guides are written
Numbers over adjectives. Every guide gives the alloy, the tolerance, the grit or the standard rather than telling you a finish is high quality. Where a figure is a typical range rather than a guarantee, it says so.
We do not own machines, so nothing here is written to sell you a process we happen to have. What we sell is matching, and matching only works when the buyer knows what to ask for.
All 34 guides
- Design for Manufacture
Shielding an Audio Chassis Without Guessing
Seams, gaps and gaskets decide whether a metal box shields anything. Anodize is an insulator, aperture length beats area, and what to put on a drawing.
- Design for Manufacture
Making a Tube Amplifier Chassis That Survives the Heat
Valve amps run hot, weigh a lot and put mains voltage on an exposed top plate. Material, thickness, socket cutouts, ventilation and the safety points.
- Design for Manufacture
Panel Cutouts for XLR, RCA, IEC and Jack Connectors
A working reference for connector panel cutouts on an audio chassis, plus the panel thickness limits and positioning rules that decide whether parts fit.
- Design for Manufacture
Transformer Mounting: Weight, Hum and the Metalwork
A mains transformer is the heaviest thing in the box and the loudest source of hum. Bolt patterns, plate thickness, the shorted turn problem and callouts.
- Design for Manufacture
Why an Audio Chassis Rings, and What the Metalwork Can Do
Thin panels ring, flat faces radiate and a transformer excites both. Ribs, mass, constrained layer damping, and which of them a machine shop can deliver.
- Finishing
Anodize Colour Matching Across a Batch and Across a Year
Why the faceplate and the knob come back different shades of black, what controls anodize colour, and how to write a spec a finisher can repeat next year.
- Design for Manufacture
Designing a Folded Sheet Cover That Fits and Looks Right
Bend radius, bend allowance, minimum flange length and why a folded box is never square. What a press brake can hold and how to draw around its limits.
- Cost
What an Amplifier Chassis Actually Costs to Manufacture
What you actually pay for in an audio chassis: billet versus extrusion, the finish line, engraving, and why 30 units cost so much more per piece than 300.
- Design for Manufacture
Machining Terminal Plates and Binding Posts for Speakers
Binding post spacing, anti-rotation, plate thickness and the plating choices that decide whether a terminal still turns cleanly after five years of use.
- Finishing
Ra, Rz and Why Neither Describes How a Panel Looks
Surface roughness numbers are useful on a sealing face and misleading on a cosmetic one. What Ra measures, what it misses and what to specify instead.
- Cost
What Minimum Order and Lead Time Really Mean on Audio Work
Why finishing sets the minimum order rather than machining, where the weeks actually go in a twelve week quote, and how a small brand plans around both.
- Cost
How a CNC Volume Knob Is Made and What Drives Its Price
Billet aluminum or brass, knurl or flute, set screw or collet: what each choice does to the cost of a machined volume knob and to how it feels in the hand.
- Design for Manufacture
How Tolerances Add Up Across an Audio Assembly
Worst case against statistical stacking, why chained dimensions cost money, and how to choose datums so the features a customer sees stay under control.
- For Shops
How to Price a Cosmetic Part When You Normally Quote Brackets
Cosmetic work looks like ordinary machining and prices nothing like it. The lines a general job shop leaves out, and how to put a number on appearance risk.
- For Shops
Should a Machine Shop Bring Anodizing In House?
The case for and against an in house line, what a managed finisher relationship needs instead, and the volume at which the arithmetic actually changes.
- Design for Manufacture
What a Turntable Platter Needs From the Shop That Machines It
Flatness, runout, dynamic balance and material choice on a machined platter, plus the drawing callouts that separate a usable quote from an expensive guess.
- For Shops
Reading an Audio RFQ Before You Spend an Hour on It
Hi-fi work has good customers and expensive ones, and the drawing usually tells you which. The signals that separate a repeat account from a rejected batch.
- For Shops
Showing Buyers You Can Repeat a Finish, Not Just Produce One
Every shop website says precision and quality. What buyers of cosmetic parts actually look for, and the specific proof that separates you from the machine list.
- Choosing a Supplier
How to Choose a Machine Shop for Cosmetic Audio Parts
The questions that separate a shop that can make your faceplate from one that can make it twice. What to ask, what to send and what to check on arrival.
- Finishing
Which Aluminum Alloy to Use for an Anodized Audio Part
6061, 6063, 6060 and 5052 all anodize differently. What each one does to colour, clarity and machining, and why mixing two alloys in one product causes trouble.
- Finishing
How to Specify a Brushed Finish on an Audio Front Panel
Grit number, grain direction, dry versus wet brushing and why the grain has to continue across two parts. The callouts that make a brushed panel repeatable.
- Finishing
Bead Blasting Before Anodize: What It Fixes and What It Hides
Glass bead, aluminum oxide and grit size all change how an enclosure looks after anodize. How to specify a blast finish so batch two matches batch one.
- Finishing
Marking a Front Panel: Engraving, Laser, Silkscreen or Pad Print
Five ways to put a logo and channel labels on a front panel, what each costs, how each survives ten years of use and when in the process each one happens.
- Finishing
Making Brass and Copper Audio Parts That Do Not Turn Brown
Brass knobs, copper trim and bronze feet look superb and tarnish fast. Alloys, lacquers, plating and the drawing notes that stop a batch ageing on the shelf.
- Cost
Getting 30 Parts Anodized Without Paying for 300
Anodizers price by rack and by tank time, not by piece. What that means for a boutique audio run and six practical ways to keep a small batch affordable.
- Cost
Billet, Extrusion or Folded Sheet: Choosing How to Build a Chassis
The three ways to make an audio enclosure, what each one really costs at 30 units and at 300, and how to mix them without the finish giving the joint away.
- Design for Manufacture
Specifying and Machining a Heatsink Extrusion for an Amplifier
Fin geometry, thermal resistance ratings, extrusion tolerances and the secondary machining that turns a length of raw profile into a chassis side panel.
- Design for Manufacture
Getting a 19 Inch Rack Panel Right the First Time
EIA-310 panel widths, 1U to 6U heights, mounting hole positions and the clearances that stop a beautifully machined panel from fouling the rack rails.
- Design for Manufacture
Machining Headphone Cups and Yokes That Match Left to Right
Mirrored parts, acoustic chamber tolerances, gimbal fits and why a pair of headphone cups is one part number with two halves, and not two part numbers.
- Design for Manufacture
Telling a Machine Shop Which Faces the Customer Will See
A cosmetic face is a specification, not an assumption. The notation, the zones and the criteria that make appearance something a shop can quote and measure.
- Design for Manufacture
Why the Panel Gaps Look Wrong When Every Part Measures Right
Gap is a system property, not a part property. How tolerance stacks up across a chassis, and the design choices that make a gap look deliberate, not accidental.
- Design for Manufacture
Isolation Feet and Spikes: Threads, Materials and Finish
Feet are the cheapest part of a hi-fi product to get wrong. Thread choice, levelling range, tip design, damping inserts and how to stop them marking furniture.
- Choosing a Supplier
Running a First Article on a Part Where Appearance Is the Spec
A standard FAI measures dimensions. On an audio part that is half the job. What to ask for, how to judge it and what to write down so batch two matches.
- Choosing a Supplier
How Finished Audio Parts Get Damaged Between the Shop and You
Most cosmetic rejects are created after the part was made. Protective film, interleaving, tray design and the packing clauses worth putting in the order.