2. amps-preamps
  3. 1049118322

Amplifier speaker relay problems.

Hi, I am working on an Niko Alpha II amplifier it is an older amp with the two large VU meters on the front. There is a problem when powering up that one chanel may not work. I have tracked this down to a relay that is in the speaker output path and is 24volt dc with two normally open contacts. It is on a printed circuite board and I wish to change it as cleaning did not help and I am afraid it may be degrading sound when working if not providing a good path. I uderstand this relay helps prevent thump on powerup and the sound from dithering out on shut down. Thank You for any advice.
guycom
guycom OP
20 posts
 
So Just let me know if I have this correct. Remove the relay and run the two normally open swich legs thrue a 1/2 amp fuse.
Thank You,
Guycom
bob_bundus
1,834 posts
 
Guy this is so easily fixed. All you need to do is burnish the relay's normally open contacts, which are now dirty & degraded from the years of use. Go to Radio Shack or check their website for a relay contact burnishing tool. These are like a very fine nail file, but are coated with diamond dust on both sides. You simply insert the spatula end in between the contacts, then apply finger pressure to the relay armature to hold the contacts against the tool, then file with an in/out motion. If both sides of the tool aren't abrasive (some are / some aren't) then turn it over & do the opposite contact. Spray or hand apply some good oilfree contact cleaner afterwards. Crocus cloth (a very fine abrasive) found in better hardware stores will also do a good job, & is cheaper too.
guycom OP
20 posts
 
Thanks Bob I will give that a try first,
Regards, guy
guycom OP
20 posts
 
Update- crocus cloth worked. Also corected a low left channel at slight volumes. Thank you both for the advice regards, Guy
bob_bundus
1,834 posts
 
you're very welcome Guy - wish that they were all this easy!
More to discover