Damaged Barrier Strip

Mike Phillips Leave a Comment

The ground screw of the input/output barrier strip on a 310 that I’m refurbishing had a seized thread that caused someone to twist the head off. After a little research, I found that the Cinch 5-140-Y barrier strip is an exact replacement. If you need to order one, be aware that many of the pictures that sellers use for these parts are incorrect. The “Y” terminal is a solder tail that feeds through back panel into the case.

Cinch 5-140-Y

Cinch 5-140-Y

The original on this one was made by Kulka, but the Cinch fits perfectly. Cinch may have been used by the factory in some models.

Remove the existing strip by removing four screws. Let the strip hang away from the back of the DAP. Gently remove the heat shrink tubing around each wire. Thread each wire into a short piece of 1/8″ heat shrink tubing before sweating it back onto the proper Y solder tab. Shrink the tubing so that none of the wiring can short against the metal case. Re-install the strip. Good as new.

The DAP 310

Mike Phillips 18 Comments

The Dorrough Discriminate Audio Processor Model 310 revolutionized radio processing. After its release in 1973, about 9,000 units were sold. AM and FM radio enjoyed a new fidelity that it had never seen before.

The DAP inspired a lot of radio engineers and technicians to test their favorite modifications. The crossover points were changed. The peak limiter was disabled. The release times on the compressor cards were decreased. The list goes on. A lot of people learned more about audio from working with their DAPs than they did from any other single piece of equipment. Along the way, Mike and Kay Dorrough gave generously of their time and their spare parts keeping owners and operators happy.

Not all of the replacement parts necessary to keep DAPs alive are still available. However, unless the printed circuit boards or meters are damaged, almost all DAPs can be brought back to life and returned to service. Internet broadcasters have started buying up DAPs and having them restored. They work extremely well for that application, and they sound great.

It would be impossible to identify all of the modifications that have been made to DAPs over the years. Some of them are Dorrough-sanctioned, many of them are not. The fact of the matter is, if a DAP is restored to its original condition with very few modifications, it can be a wonderful sounding piece of equipment.

There have been lots of copycats and claimed improvements by competitors over the years, but there has been only one DAP. There is no question that Mike Dorrough is the father of multiband audio processing. This website is dedicated to this piece of history that thankfully will just not go away. Hopefully you will find content here that will help you maintain your DAP or at least to reminisce about the good old days.

Now, click on “RECENT POSTS” for even more DAP love.