Roaring Sound from Nikko Solid-State Stereo Amplifier

[lukelafayett]

Hi,

Occasionally I here a roaring sound from speakers hooked up to my vintage Nikko Solid-State Stereo Amplifier. It sounds like a stiff outdoor breeze across a microphone. I want to replace the component causing the sound. Would anyone know what that component is?

Also, the Nikko stereo amp is from the early 70's and all original. Is there any other parts that are typical in needing replaced?

Thanks.

 

[Citation-Fan]

Maybe the voicecoil off one off your speakers are damaged?

 

[elnaldo]

Welcome to AK !!

Some amps are simply a bit noisy, as mine. If I put my ear beside the tweeter, I hear a "hsssss".

Can you swap speakers, or amp? Is the noise from both channels?

In an original '70 amp, never serviced, it could be some faulty component in the unit, some components go out of specs with time, capacitors, transistors, resistors... Mostly capacitors.

Try to isolate the problem, if you have a preamp output, connect it to a different power amp, swap speakers, swap amps, try to determine if the noise comes from the preamp, the power amp or the speakers (speakers usually don't produce sound by themselves), check if the noise changes with volume or tone controls (this can give you an idea of the source of the problem)

In the meantime try to get a schematic or service manual of your amplifier.

 

[EchoWars]

Dying transistors or diodes make the sound you are describing.

 

[lukelafayett]

Thanks for getting back to me, guys. An old and defective capacitor, transistor or diode answers my questions. Would anyone know the best way or device to begin testing each component?

Thanks.

 

[sregor]

Model #? One method of finding noisy components (especially intermittent ones) is to tap components (with non conductive "instrument" ).
Probably is not related, but one frequent problems with old nikko amps are the adjustment resistors get flaky (not just Nikko's either) My 2 cents.

 

[specialone53]

Thanks for getting back to me, guys. An old and defective capacitor, transistor or diode answers my questions. Would anyone know the best way or device to begin testing each component?

Thanks.

Starting at the output, and working forward with a signal tracer is best.
But the problem has to rear its ugly head in order to perform this troubleshooting procedure.

 

[theophile]

Have you got anything hooked-up to the 'Lion Out' sockets?