FAQ: Repairing Vintage Eventide Equipment

This page may be of assistance to owners of ancient Eventide products that are no longer eligible for factory repair.  Despite the age of our oldest products (30 years plus!) they may still work or be made to work with only minor difficulty.  Here are some hints.

What goes wrong?

Equipment can fail at any time for any reason, such as random component failure.  But we're talking about old equipment here, so let's consider problems related to age. 

Exposure - it's simply been exposed to the atmosphere and environment for a long time.  Look for:

Mechanical damage

Long, hard usage - it's been powered up in a rack forever

Burnt circuit boards
Components that dissipate power may have failed
Switches and other mechanical components are likely to suffer
Indicators, especially incandescent, are bad

So what to do?  First, clean it, inspect it, and smell it.  The last is especially important!  If nothing is obviously wrong, plug it in and see if it lights up.  Check it in the Bypass position to make sure the connectors (and your connections) are OK.  If it doesn't work when bypassed and the switch is good or the relay is clicking, you probably haven't connected it correctly!

Q:   The unit powers up and everything looks good, but the audio output has a lot of hum.

A:    Check for ripple on the power supply lines.  If you see 120Hz ripple, probably the power supply filter capacitors need to be replaced.  If you see 60Hz ripple, then the bridge rectifier may have one bad diode.  (These two problems account for a very large percentage of defective units!)

Q:    I have one of your older digital products and I hear a periodic clicking in the audio output.  (The unit may or may not be working otherwise.)

A:    The don't make memory chips like they used to-they're much better now.  What you probably have is a bad memory chip, and you may or may not be able to find a replacement.  One simple semi-fix is to swap chips around to get the defective one in the LSB (least significant bit) position.  A few bad bits in the LSB may be almost inaudible.

Q:    I have a question that isn't covered here.

A:    Email it to us and if it seems to be of general interest we'll add it here.