[Boatanchors] SX-122 hum and noise

[Glen Zook]

Especially when using "modern" low impedance headphones with sets that were designed for high impedance (i.e. 2000 ohm) headphones there is almost always a definite hum present.  When using high impedance headphones any hum is usually so low in volume as not to be readily noticed.

Also, tighten all of the machine screws and nuts that go through the chassis.  These come loose and/or become corroded over the years.  The circuit grounds in the unit are made through these.  I have fixed many a problem in "boat anchor" equipment just by tightening these connectors.  Unfortunately, a lot of the factory built equipment used rivets instead of machine screws.  These also become loose and/or corroded.  However, they are a lot harder to tighten.  Some people have been successful using a punch and hammer to tighten the rivets.  Others go ahead and drill out the rivets and replace with machine screws.  Either way it is going to take some effort.

Glen, K9STH

Website:  http://k9sth.com


--- On Fri, 3/26/10, Bob Macklin <macklinbob at msn.com> wrote:

The question I did not see asked is does the hum change with the volume control?
 
Is it speaker hum or headphone hum?