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N_Cook N_Cook is offline
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Default Yamaha Stagepas 300 failure mode

Gareth Magennis wrote in message
...

"N_Cook" wrote in message
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Gareth Magennis wrote in message
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"Ron" wrote in message
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On 31/01/2012 11:05, N_Cook wrote:
Just as well I'm not paying Yamaha 50 squid a pop for these blown
amps.
Repaired one end of 2011 , it bounced back.
It is due to the short stub lead between amp and its immediate
speaker,
the
elbow connectors.
No name elbows on lead marked UPOFC Classic Pro Loudspeaker Cable.
Took

a
bit of grinding to cut the top off the elbow, quite thick monkey
metal.
The
ground connection out to the cable solder point is like a solder tag

but
with a 2mm x 1mm x tag thickness lug opposite the solder extension

,that
locates into the moulded plastic insulator. The tag is not spot
welded/bolted to the elbow metal so any twisting of the cable is
transfered
to the tag and the ring part can twist and touch the conductor stem

to
the
tip, as the cylinder insulation along this stem does not extend into

this
solder tag, or perhaps as only touching ground contact, then

localised
heating and the cylinder insulation melting back a bit. I've not

explored
that far in, the top moulded insulation plastic does not look

melted.
These elbows have a vague brassy/coppery tinge of plating or

something
just
on the tips , the main elbow body is Hex in plan and between it and
the
stem
is what looks like a hank bush swage-form.



Several people have reported that their problems began when they
started
using speaker cables other than those supplied with the units which

sadly
are just not quite long enough.

Ron


The thing is, Yamahas user manual specifically warns against using
speaker
cables other than those supplied with the units, so they are covered.

e.g.

11 Only use attachments/accessories specified by the manufacturer.

and:

To avoid any possible malfunction, use only the speaker cables included

with
the device




Cheers,


Gareth.




The foot long lead is not original Yamaha. The general warning applies
about
these non-moulded , ie user applicable solder-on tags with screw-on
knurled
barrel over the cable entry. The soldering and choice of cable was fine,
it
is a bad design of connector





So not really a Yamaha Stagepass 300 failure mode as the thread title

states
then.



Cheers,


Gareth.




It seems its a fault of Yamaha supplying 2 "long" leads only. Or this owner
from new received only 2 "long" leads and no foot long lead. He got a shop
to make up a foot long lead, and a long-long lead, nothing wrong with the
job they did, unknowingly bad choice of elbows .
Both long leads are not long enough for normal purposes if used as amp and 2
separated speakers. Does Y expect people to coil up the long lead and drape
it around the "powered speaker" unit clamp or something?
This Stagepas is only used as a "powered speaker" and an outlier speaker
with a longer lead than Y supplied.

If Y supplied 3 appropriate leads all with moulded-on connectors then these
faults (including the other pitfall of metal elbows and the grounded handle
and the antiphase "left" channel o/p) would not emerge