Tech's Files: Servicing Vintage Audio Gear

Sep 9, 2010 2:18 PM, By Eddie Ciletti

WHEN IT'S NOT THE TUBE, TRANSISTOR OR OP AMP

Polls


Education Guide

Mix is gearing up to present its longstanding annual Audio Education Guide in its November 2014 issue. Want to have your school listed in the directory, or do you need to update your current directory listing? Add an image, program description, or a logo to your listing! Get your school in the Mix Education Guide 2014.

A soft wire brush is useful for burnishing tube contact pins.

A soft wire brush is useful for burnishing tube contact pins.

SNAP? CRACKLE? POP?
When a faulty instrument, line or speaker connection isn’t the cable, the crackles can be due to loose or tarnished input/output connectors. Don’t be lulled into a false sense of security by nickel-plated phone plugs. They may look shinier than brass patch plugs, but some non-conductive “films” can be transparent—almost like satin-finish lacquer. The off-the-shelf solution is to burnish the plug with a 3M Scotch-Brite scrubber pad (or equivalent).

Visual inspection of XLR males is easier when the connectors are removed from their shells. Silver-plated connectors can oxidize black, which is not only visually obvious, but can also turn the connection into a diode, rectifying the audio into a mysterious, distorted nightmare. Limited space makes burnishing XLRs a second choice to chemical treatment, aka Silver polish. I haven’t tried Hagerty products, but I have used Tarn-x and it’s very effective. As with all chemicals, heed the warning and work in a well-ventilated area.

A toothpick or bamboo skewer is handy for cleaning tube sockets.

A toothpick or bamboo skewer is handy for cleaning tube sockets.

Don’t overtighten plastic jacks; take the time to pop the cover to see that the opposite side isn’t obviously damaged (or spinning or unsoldered). As mentioned earlier, if the connector is soldered to a PCB, it’s important to inspect for both broken traces and a “cold” (weak/poor) solder joint.

If swapping tubes makes nasty crackles, the socket or pins might be dirty. A soft, fine-bristled (0.1mm) brass-wire brush (see Fig. 2) works well on tube pins. To clean the 7- and 9-pin tube sockets, start with a round toothpick dipped in anhydrous (99-percent alcohol) or denatured alcohol. (See Fig. 3.) Don’t push too hard, but do rotate. If the toothpick comes out gray-black, then it needed to be done. Follow up with a fresh pick dipped in a contact cleaner/preservative such as Stabilant 22 or Caig DeoxIT. If cleaning reduces but doesn’t eliminate the crackle, a fatigued socket or cold solder joint might be at fault. If a replacement is necessary, consider using ceramic sockets. Physically strong and with low capacitance, these are a better choice than plastic sockets.

You may not be ready to dive directly into component-level servicing, but by following a logical approach to signal flow and paying attention to simple details (such as clean connections), you’ve come a long way toward keeping your vintage gear in prime operating condition.


Visit Eddie Ciletti at www.tangible-technology.com.






Acceptable Use Policy
blog comments powered by Disqus

Mix Books

Modern Recording and Mixing

This 2-DVD set will show you how the best in the music industry set up a studio to make world-class records. Regardless of what gear you are using, the information you'll find here will allow you to take advantage of decades of expert knowledge. Order now $39.95

Mastering Cubase 4

Electronic Musician magazine and Thomson Course Technology PTR have joined forces again to create the second volume in their Personal Studio Series, Mastering Steinberg's Cubase(tm). Edited and produced by the staff of Electronic Musician, this special issue is not only a must-read for users of Cubase(tm) software, but it also delivers essential information for anyone recording/producing music in a personal-studio. Order now $12.95

Newsletters

MixLine

Delivered straight to your inbox every other week, MixLine takes you straight into the studio, with new product announcements, industry news, upcoming events, recent recording/post projects and much more. Click here to read the latest edition; sign up here.

MixLine Live

Delivered straight to your inbox every other week, MixLine Live takes you on the road with today's hottest tours, new sound reinforcement professional products, recent installs, industry news and much more. Click here to read the latest edition; sign up here.

[an error occurred while processing this directive]

The Wire, a virtual press conference offering postings of the latest gear and music news, direct from the source. Visit the The Wire for the latest press postings.