The TAB Guide to Vacuum Tube Audio: Understanding and Building Tube Amps (TAB Electronics) by Jerry Whitaker

Author:Jerry Whitaker [Whitaker, Jerry]
Language: eng
Format: epub
Publisher: McGraw-Hill Education
Published: 2011-10-19T21:00:00+00:00

FIGURE 6.1 Chassis construction techniques: (a) selection of chassis punches for use with tube-based projects; (b) the chassis is covered with masking tape to facilitate marking of hole positions and sizes for the components; (c) use a drill press for precision cuts and control over the workpiece; (d) after the holes are punched, check for proper fit; (e) completed chassis.

The front panel of the unit can present the greatest challenge because it is what most people will see most of the time. The front panel must provide mechanical support for user-operated controls and include legends for those controls (e.g., “volume,” “power,” etc.). While press-apply legends are easy to use and inexpensive, the finished look may be less than desired. As with the sheet metal work, a local vendor may be able to help.

Although more expensive than a do-it-yourself front panel, vendors are available that specialize in short-run or prototype front panels. The clear benefits here are a professional appearance and durable finish. For projects in this book, the author used the following services, which provided good results:5

• Screen-printed polycarbonate overlay This vendor (Metalphoto of Cincinnati, www.mpofcinci.com/) will work with the customer to design a custom panel or work from a customer-supplied drawing file (AutoCAD, Adobe Illustrator, and other formats). The overlay is printed and then affixed to a metal backer (the chassis front panel), and the necessary openings (holes) are punched in the overlay. A wide variety of options are available, including turnkey services. The polycarbonate overlay is quite durable and can include any number of legends and colors. This approach provides a professional appearance for all types of instruments.

• Engraved panel This vendor (Front Panel Express, www.frontpanelexpress.com/index.html) offers a free software package that allows the user to design chassis panels (or an entire enclosure) and transmit the design to the company, which then provides a bid and ultimately the finished product. Options include 1) the type, finish, and thickness of the panel; 2) legend fill colors; 3) holes and openings; and 4) custom engravings. This approach provides a professional appearance for consumer electronics products.

For a do-it-yourself approach, the chassis and front panel will, invariably, need to be painted. Make sure and use the right paint for the job—one that will adhere to the metal finish and provide good scratch-resistance. Here again, a local vendor may be the best way to go.

Many painting options are available. Spray paint is readily available in a number of colors and textures. Use of a primer is advisable. The chassis and other metal components can typically be purchased finished or unfinished. Try various paints on sample pieces of metal before settling on a final selection. Some painting considerations are illustrated in Figure 6.2.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.