[sdiy] hum horror

[Dave Krooshof]

>Anyway, my Big Muff Pi has developed some nasty hum. Touching the
>enclosure makes it worse. Turning the effect on seems to route the hum
>through the effect. Removing the battery helps nothing. However, when
>driven through the DOD PDS 20/20 (BBD), the hum disappears.

As in:
Instrument -> Big Muff -> mixer                      = hum
Instrument -> Big Muff -> DOD -> mixer?        = no hum

Then I'd suspect my cables.
Could also be that a jack fails to connect; dirty or broken 'female'.
Could also be that one of the sockets *needs* a mono jack, either
to switch something on, or because ground is connected to the ring
or even to the tip, in stead of to the sleeve.
(I once managed to make the mistake of reversing tip and sleeve on a odd
jack female socket.)

>Touching the enclosure makes it worse.
What happens if you take a wire and connect the enclosure of the Big Muff
to the ground of one of the mixers inputs? Does the hum disappear?
If so, check connectors and solder joints.


Dave
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Ps: I loved the Way OT thread, as I find it important to know what you guys
think of the worries that run through my head too while soldering.
Sdiy fills the gap of not being able to discuss audio electronics with my
real life friends to the extent of this list, likewise I it's a completion if
*sometimes* we get so OT, discussing such important issues.
Rick offered several times to open a sdiy-chat list. Maybe we could go for
that.
And make <!!!>that one only</!!!> it digest-available :-)
I so much disagree with the 'the list should be sterile' remark.
So non human.
Stay human.

Dave