Forte 1a buzzing/humming fixed?

needtubes · 4th August 2007, 08:18 PM

I bought a Forte Audio 1a about two years ago and it has been sitting unused the entire time because it always hummed and buzzed really loudly, especially in the left channel. Well, I opened it up the other day and noticed one of the thermistors (?) was not touching the heatsink (had thermal grease on it). So, I bent the wires around a little and got it touching it. I finally got around to hooking the amp up today and the hum/buzz is miraculously gone! There is still a faint 60Hz hum in the woofers and buzz in the midrange and tweeter in the left channel, but it is only audible from about two inches or so. Otherwise, it is dead silent and sounds great!

The whole time, I thought my hum and buzz came from the DC voltage on my AC line (measures about .6V to .8V with a multimeter). Now, the DC is still there but I have no hum. Could the problem have been the thermistor the whole time?

Nelson Pass · 4th August 2007, 09:08 PM

Maybe, but I think it's just as likely that your opening and
closing of the chassis altered something.

needtubes · 5th August 2007, 03:54 PM

Hmm... Well, I was really hoping I had an answer that sort of made sense because this whole situation has bothered me for two years. Now it is suddenly gone...

I guess I should just be happy that it works!

AndrewT · 5th August 2007, 04:02 PM

Hi,
sometimes the greatest discoveries follow an unexpected outcome.

It is the thinking about why it happened that will lead to the explanation and the result will teach you more about your audio circuit than you know now.

4th August 2007, 08:18 PM	#1
needtubes diyAudio Member Join Date: May 2003 Location: USA	Forte 1a buzzing/humming fixed? I bought a Forte Audio 1a about two years ago and it has been sitting unused the entire time because it always hummed and buzzed really loudly, especially in the left channel. Well, I opened it up the other day and noticed one of the thermistors (?) was not touching the heatsink (had thermal grease on it). So, I bent the wires around a little and got it touching it. I finally got around to hooking the amp up today and the hum/buzz is miraculously gone! There is still a faint 60Hz hum in the woofers and buzz in the midrange and tweeter in the left channel, but it is only audible from about two inches or so. Otherwise, it is dead silent and sounds great! The whole time, I thought my hum and buzz came from the DC voltage on my AC line (measures about .6V to .8V with a multimeter). Now, the DC is still there but I have no hum. Could the problem have been the thermistor the whole time?

5th August 2007, 04:02 PM	#4
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, sometimes the greatest discoveries follow an unexpected outcome. It is the thinking about why it happened that will lead to the explanation and the result will teach you more about your audio circuit than you know now. __________________ regards Andrew T.

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4th August 2007, 09:08 PM	#2
Nelson Pass The one and only Join Date: Mar 2001	Maybe, but I think it's just as likely that your opening and closing of the chassis altered something.

5th August 2007, 03:54 PM	#3
needtubes diyAudio Member Join Date: May 2003 Location: USA	Hmm... Well, I was really hoping I had an answer that sort of made sense because this whole situation has bothered me for two years. Now it is suddenly gone... I guess I should just be happy that it works!

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