Buzz / Noise on high volume (T-522)

[Guest]

I have a t-522.</p>

At higer volumes i get a buzzing sound. I think it's Power amp related.</p>

It's on the peakes, and on higher volume. It comes from the 2x12"</p>

and the built in leslie. It's also present at high volume using the rythem box.</p>

Any idees ?</p>

(It's not 60hz hum, more like a loud click)</p>

Also i have a load click when i turn power on, could it be related. ?
</p>

[Clarion]

Re: Buzz / Noise on high volume (T-522)

The sound you describe is consistent with a defective speaker.

[fredy2]

Re: Buzz / Noise on high volume (T-522)



Also check that speakers are securely mounted. Loose speakers or other hardware can fool you.</P>


Disable one speaker at a time by unconnecting one lead and using a dummy load resistor... probably 8 or 10 ohms 50 watts would be good... isolate a bad one or one that is causing the noise that way.</P>

[hh]

Re: Buzz / Noise on high volume (T-522)

dummy loads aren't required since it's a transistor amp. Less speakers makes an easier load for the amp.

[fredy2]

Re: Buzz / Noise on high volume (T-522)



Sometimes dummy loads ARE required for transistor amps... Certain amps may go into a parasitic oscillation when lightly loaded or havecrossover problems and possible shoot through.</P>


More important is that having the amp loaded near normal may show failures within the amp itself due to poor power supply regulation under load...</P>


Usually the loads are not required for safety purposes, but there are a few exceptions.</P>


For bipolar transistors that are major power types they can become saturated without the usual load to help sweep the carriers out of the base region.</P>


Some MOSFET amps can become unstable due to high frequency feedback when lightly loaded. Just had one of those to fix... These are subtle design problems.</P>


Usually even a small load will prevent problems.</P>