Well there's no sign of water in there Nick,maybe it's a dry jointNick wrote:Looking at the circuit Phil posted both N and L should be floating.
Poorly Rogers
#17
Hi Nick,
Found the short,it was caused by the signal fly-lead moving
So,back to the buzz/hum........
Immediately after switch-on,i noticed R18,a 2.2R 4W wirewound,was cooking. Obviously i switched it off,but i suspect that may be where my problem lies.
Any further thoughts or suggestions please?
Cheers
Martin
Found the short,it was caused by the signal fly-lead moving
So,back to the buzz/hum........
Immediately after switch-on,i noticed R18,a 2.2R 4W wirewound,was cooking. Obviously i switched it off,but i suspect that may be where my problem lies.
Any further thoughts or suggestions please?
Cheers
Martin
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#19
Hi Martin-R18 is just after the transformer so it could be any part of the circuit that is drawing more current although i would have thought its on the channel thats buzzing.
But then,what do i know ?
If were me i would power it up and measure voltages at the same point on each channel and see where the differences are.
But then,what do i know ?
If were me i would power it up and measure voltages at the same point on each channel and see where the differences are.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#21
Ok, the resistor will be getting hot because its passing too much current, its unlikely to be the problem itself.
I would try disconnecting the center tap from the output transformer that is buzzing, insulate it, and then turn on again, and see if the resistor still gets hot.
It may be the transformer is shorted internally, hence the buzzing and excesive current draw,
I would try disconnecting the center tap from the output transformer that is buzzing, insulate it, and then turn on again, and see if the resistor still gets hot.
It may be the transformer is shorted internally, hence the buzzing and excesive current draw,
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#22
Well Nick,
As i couldn't actually remember which channel was humming,i took the cover off the OPTX,and connected it up quickly to identify which channel it was......and guess what?
No hum!
Not a sausage,bugger all!
I should of done voltage checks,i know,but curiosity got the better of me,i put the valves back in. And guess what?
No hum,back to playing music again!
Now explain that
Been playing for an hour now,no probs.
Thank you very much for your help Nick,perhaps i just hurt Roger's feelings
Kindest Regards as always
Martin
As i couldn't actually remember which channel was humming,i took the cover off the OPTX,and connected it up quickly to identify which channel it was......and guess what?
No hum!
Not a sausage,bugger all!
I should of done voltage checks,i know,but curiosity got the better of me,i put the valves back in. And guess what?
No hum,back to playing music again!
Now explain that
Been playing for an hour now,no probs.
Thank you very much for your help Nick,perhaps i just hurt Roger's feelings
Kindest Regards as always
Martin
