- Aug 10, 2019
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hi guys,
you may have seen in the show your system section that i am currently running a pretty old (circa 1983) harman/kardon hk770 power amp as part of my system.
i've only had it fitted for a week or so, but something is really bugging me! i've disconeccted the speakers now and hooked them back up to my azur 650a until i can be satisfied that this won't harm them.
basically, when you switch it on there is a short delay (circuits powering up i suppose) followed by a clicking relay, at exactly that moment the right hand speaker will pop quite loudly. if you take the cover off the speaker you can actually see the drivers 'pump' outwards before settling sort of 3/4 of the way back from where they started (if that makes any sense?!) if you switch the amp off the drivers will fall back to their natuaral position.
it is not affected by turning down volume etc, and if you switch on with speaker set b engaged (nothing connected) then switch over to 'a' it still happens, it even occurs if the pre amp is off.
if i unplug the right hand speaker, i still hear the clicking relay, but no sounds/ driver movement from the left hand speaker whatsoever. Thi leads me to believe that what is going on with the right speaker is pretty abnormal and potentially detrimental to it!
I should add that there does not to seem to be any distortion or background noise when playing, and music sounds great through it!
i have read some information about cheking the dc output balance on the terminals, so i will check that tonight (could this be caused by an imbalance?) i suppose there could be a dodgy relay for the right channel or something.
thanks in advance for any assistance, fingers crossed its nothing to bad, i do love the sound that this has given to my setup!
cheers
Dan :help:
you may have seen in the show your system section that i am currently running a pretty old (circa 1983) harman/kardon hk770 power amp as part of my system.
i've only had it fitted for a week or so, but something is really bugging me! i've disconeccted the speakers now and hooked them back up to my azur 650a until i can be satisfied that this won't harm them.
basically, when you switch it on there is a short delay (circuits powering up i suppose) followed by a clicking relay, at exactly that moment the right hand speaker will pop quite loudly. if you take the cover off the speaker you can actually see the drivers 'pump' outwards before settling sort of 3/4 of the way back from where they started (if that makes any sense?!) if you switch the amp off the drivers will fall back to their natuaral position.
it is not affected by turning down volume etc, and if you switch on with speaker set b engaged (nothing connected) then switch over to 'a' it still happens, it even occurs if the pre amp is off.
if i unplug the right hand speaker, i still hear the clicking relay, but no sounds/ driver movement from the left hand speaker whatsoever. Thi leads me to believe that what is going on with the right speaker is pretty abnormal and potentially detrimental to it!
I should add that there does not to seem to be any distortion or background noise when playing, and music sounds great through it!
i have read some information about cheking the dc output balance on the terminals, so i will check that tonight (could this be caused by an imbalance?) i suppose there could be a dodgy relay for the right channel or something.
thanks in advance for any assistance, fingers crossed its nothing to bad, i do love the sound that this has given to my setup!
cheers
Dan :help: