PCB Design
This page gives information on designing printed circuit boards for analogue audio circuits. Personally I prefer working with through-hole components for easier handling. All my designs use at least two layers, as this will greatly simplify and speed-up the routing and allows the use of generous ground planes on both layers. I found the use of ground planes beneficial even for circuits usually classified as uncritical.
Pad And Drill Sizes
The following table lists my default pad and drill sizes for the most often used through-hole components. Paired values for the pad size indicate asymmetric (i.e. elliptic instead of circular) pads. Allways double check with the datasheet if your footprint matches the component to be used!
| Part Type | Pad Size | Drill Size |
| TO-78 package | 60 mil | 30 mil |
| vertical resistors, vertical DO-35 diodes, TO-92 package | 70 mil | 35 mil |
| resistors, small capacitors, inductors, DO-35 diodes, TO-126 package | 80 mil | 35 mil |
| DIP/DIL packages | 70/90 mil | 35 mil |
| TO-220 package | 80/100 mil | 45 mil |
| power resistors, large capacitors, DO-41 diodes, connectors | 100 mil | 45 mil |
| power resistors, 17-02 diodes | 120 mil | 55 mil |
Track Width And Clearance
For standard circuitry I use a 20 mil track width for the low-power signal routing and 50 mil for the power traces (e.g. supply lines and line driver sections). For tight routings (e.g. around TO-92 transistors) I often use 10 mil tracks. For traces with more than 100 mA current flow—most often seen in power supplies—I increase the width to 80 mil. The width for the ground plane connects is set to 20 mil.
My default general clearance is 10 mil. Clearance to ground planes is increase to 20 mil for lower stray capacity and easy solderability.
Resources
PCBDesignTutorialRevA.pdf
Very good beginners guide to PCB design.
anatomy of a plated hole.pdf
Some details on PCB construction and good overview on terminology.
SELECTING PCB SUPPLIERS2303.pdf
Detailed information on manufacturing parameters.
Terms Of Use
The designs described on these pages are not commercial in any way. This means that I do not sell PCBs, kits, or anything like that. It also means that any for-profit use of the information on these pages is strictly prohibited—you may not sell PCBs, kits (neither partial, nor complete) or finished (or unfinished) units of the designs on this site, without the express written consent of Samuel Groner/SG-Acoustics.
Disclaimer
Notice that all information, schematics, layouts etc. are supplied as is, and that I can in no way be held responsible for its accurateness, functionality or even safety. Samuel Groner/SG-Acoustics shall not be responsible and disclaims all liability for any loss, liability, damage (whether direct or consequential) or expense of any nature whatsoever, which may be suffered as a result of, or which may be attributable, directly or indirectly, to the use of or reliance upon any information, links or service provided through this website.