Gareth Magennis wrote in message
...

"N_Cook" wrote in message
...
N_Cook wrote in message
...
RoHS date of introduction for Australia ?
Anyway 1/4 inch i/p socket too weak even for domestic use , breaking up
in
a
few years ( within RoHS regime), no obvious datecodes except main
electros
seem to be 2000, otherwise maybe 2004 or 2005 IC dates. No-name flimsey
junk
, the type with 2 insulated change over contacts. On trying to work out
the
functions, apart from the tip contact/grounding setup there is a line
to
one
of the isolated switches that grounds at plug inserted and o/c when
removed
, it goes DC connected to the base of a pnp transitor - function ?



If it kills the gain for bang-less plug insertion then it would only
work
for insertion , not removal, as that switch makes before tip
makes/breaks
ground




Maybe it mutes the reverb?



Gareth.


Luckily the owner wanted a reliable input socket and was unconcerned about
the loss of the plug-in de-thump cct. To replace the domestic headphone
socket (has isolated switching) would have been a work up as 0 or 15V on
that control line so could not use an effects pedal type ring switch action.
And the ring switch for a normal stereo 1/4 inch jack is the wrong action
for here anyway, requiring an inverter somewhere or one of those awkward and
rare offset 1/4 inch switch actions. cct proper, holds off full gain for 0.5
seconds or so after plug insertion, all the while removed 30dB or more gain
drop via 15/-15V control into the first amp. Although no obvious PbF solder
problems the original input socket had thin+wide blade pins going into holes
of that wide diameter and loads of filler solder, asking for problems with
ordinary solder let alone new-fangled


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/