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  #1  
Old 2nd November 2019, 03:31 PM
buddam buddam is offline
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Default WAD 300b hum and buzz

Hi all
I had my WAD 300b upside down the other day to check a few things and when I returned it to the system it had developed both louder transformer hum and a buzz coming through the right channel tweeter. I didn't make any changes, but moved some cables a little to get a view of cap and res values. Could that have had such an impact?

Best

Adrian
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Old 2nd November 2019, 04:51 PM
Chris Chris is offline
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Default Re: WAD 300b hum and buzz

Check for ground loops and experiment with cable layout and locations, you may also have tugged on a dry joint?

Chris.
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Old 3rd November 2019, 04:31 PM
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Phil Y Phil Y is offline
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Default Re: WAD 300b hum and buzz

Hi Adrian,

I would tend to agree with Chris, most likely you have damaged a connection or component when you were poking about. Open it up again and have a good look around for a broken wire or component leg or two things touching/shorting together that shouldn't be.

Phil.
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Old 4th November 2019, 01:23 PM
Mark Mark is offline
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Default Re: WAD 300b hum and buzz

Hi Adrian

I turned my KEL84 over recently and found the Tx were loose. On the way to the tool drawer to get a spanner to tighten the bolts I then remembered I had previously loosened the bolts a little to reduce microphony/noise transfer. I found that if the bolts were too tight they over-compressed the rubber grommets in the top plate of the case so the TX coupled too well with the steel case.

Notwithstanding the more likely causes already posted above, I would also check your TX aren't too loose and/or haven't moved slightly into better contact to transfer vibration. Moving them slightly one way or the other might get rid of the noise.

Mark
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Old 7th November 2019, 03:05 PM
buddam buddam is offline
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Default Re: WAD 300b hum and buzz

Very kind all. Thanks for the suggestions. Meanwhile....

Colin Wonfor (IncaTech) came round recently and noted loss of bass on left channel. I had a look inside and a buzz appeared on the right. Now there is nothing from either channel! I have a number of options:

1. give it away (or sell it for parts only) to someone who knows what they are doing!
2. strip it back and rebuild from scratch, with no guarantee that I am not putting faulty parts back together
3. pay yet more (this thing has cost me an arm and a leg) to have someone fix it (I was told today by a professional friend of a friend that it will cost at least 200 to fix - details to follow)
4. drive it to someone on this forum who would like to play around with it, and agree a price for repair or sale once the full scale of the problem is known
5. drop it down the front steps or pour a cup of tea on it and claim the insurance (red-faced smiley)

Any suggestions?

Cheers

Adrian
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