Grave dig. More just to update this 'blog' and for those that may come after looking for clues etc..
I currently have a lot of spare time (mmmmm dont ask
)
So decided to investigate the transformer buzz described earlier.
Heck the buzz is even there when its in 'stand by', and very slightly increases as it gets warmer.
End result, I'd say it's an actual mechanical winding/lamination issue.
I've followed Nelson's suggestions of a pair of CL60's in the mains feed - Zero difference.
I've built and installed a 'DC blocker' (bridge + two cap version) - Zero difference.
Also combined the two into one unit - Zero difference.
The only thing that stops the buzz is running it at < 220 (240vac - 20vac = 220vac via a variac).
Maybe one day I'll be able to afford to replace the transformer. Think I'll send Pass Labs an email about pricing.
So, there ya go. This poor things had the snot beaten out of it at some stage.
I strongly suspect all the damage was done while in the hands of its Hong Kong owner.
The same IDIOT that put an 8 amp fuse in the primary and blew one channels outputs.......
On the bright side it sounds even better now with the new speakers I've just finished constructing..
I currently have a lot of spare time (mmmmm dont ask
)So decided to investigate the transformer buzz described earlier.
Heck the buzz is even there when its in 'stand by', and very slightly increases as it gets warmer.
End result, I'd say it's an actual mechanical winding/lamination issue.
I've followed Nelson's suggestions of a pair of CL60's in the mains feed - Zero difference.
I've built and installed a 'DC blocker' (bridge + two cap version) - Zero difference.
Also combined the two into one unit - Zero difference.
The only thing that stops the buzz is running it at < 220 (240vac - 20vac = 220vac via a variac).
Maybe one day I'll be able to afford to replace the transformer. Think I'll send Pass Labs an email about pricing.
So, there ya go. This poor things had the snot beaten out of it at some stage.
I strongly suspect all the damage was done while in the hands of its Hong Kong owner.
The same IDIOT that put an 8 amp fuse in the primary and blew one channels outputs.......
On the bright side it sounds even better now with the new speakers I've just finished constructing..
ok final barrage of tests have been performed.
unbolted the transformer, no difference.
10mm felt between transformer and case (no bolt) - no difference.
lifting transformer with my hands, so no mechanical coupling between it and the case whatsoever - nooooooo difference.
only thing i can do from here is to fully remove it and run it on the bench. but i dont see that as being needed.
So, my verdict, it needs to be replaced.
I've sent an email to 'the creators' workshop, wait and see what $$ a replacement will be..
unbolted the transformer, no difference.
10mm felt between transformer and case (no bolt) - no difference.
lifting transformer with my hands, so no mechanical coupling between it and the case whatsoever - nooooooo difference.
only thing i can do from here is to fully remove it and run it on the bench. but i dont see that as being needed.
So, my verdict, it needs to be replaced.
I've sent an email to 'the creators' workshop, wait and see what $$ a replacement will be..
I have just finished swapping out the transformer for a new one allllll the way from Pass Labs.
It is now silent.
Was it cheap, No. (that is when you add in freight from usa to australia for ~8kg of copper and steel)
Was it easy, mmmmmm, more time consuming than anything else.
Not that disassembling the amp almost to its last bolt is fun past time :|
I have nothing but praise for ALL the staff at Pass Labs.
The effort to confirm the fault, suggest other tests, then the time to organize a new replacement.
Why oh why can we not have customer service like this everywhere....
Many thanks.
Tomorrow I'll warm it up and recheck all settings before putting it back into service...
Weeeeeeeeeeeeeeeeeeeeeeee.
It is now silent.
Was it cheap, No. (that is when you add in freight from usa to australia for ~8kg of copper and steel)
Was it easy, mmmmmm, more time consuming than anything else.
Not that disassembling the amp almost to its last bolt is fun past time :|
I have nothing but praise for ALL the staff at Pass Labs.
The effort to confirm the fault, suggest other tests, then the time to organize a new replacement.
Why oh why can we not have customer service like this everywhere....
Many thanks.
Tomorrow I'll warm it up and recheck all settings before putting it back into service...
Weeeeeeeeeeeeeeeeeeeeeeee.
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