Guides / Parts
Knobs, 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.
A knob is a small part with an outsized bill, and the reason is that almost nothing in its price is cutting time. Deburring, finishing, inspection and packing dominate, and all four get harder as the part gets smaller.
The other thread here is matching. Four knobs on one preamp, two headphone cups, four feet under one component: in every case the set is the unit, not the part. A single foot 0.2 mm short makes the whole product rock.
What this section answers
- What actually drives the price of a machined volume knob
- Flatness, runout and balance on a turntable platter, and the callouts that matter
- Headphone cups and yokes as matched pairs, including the acoustic chamber
- Isolation feet and spikes: thread engagement, tip design and set matching
- Speaker terminals, binding post spacing and anti-rotation
- Panel cutout dimensions for XLR, IEC, RCA and jack connectors
6 guides in this section
In reading order. Each one stands alone, but they are written to be read in sequence.
- Cost
Sep 14, 2026How 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
Sep 10, 2026What 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.
- Design for Manufacture
Jul 26, 2026Machining 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
Jul 14, 2026Isolation 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.
- Design for Manufacture
Sep 17, 2026Machining 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.
- Design for Manufacture
Sep 23, 2026Panel 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.
Working on a part like this?
Send the drawing. We match it with up to 3 shops that machine and finish parts for audio products, and reply within 24 business hours.
Other sections
Chassis
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
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.
Sourcing
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
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.