[AH] Fwd: Moog Voyager elusive problem, asking for your advice

From System 100
Sent Fri, May 10th 2013, 14:11

--bcaec50406ec864d5e04dc5c0f81
Content-Type: text/plain; charset=ISO-8859-1

Hi all !

I bought a second hand Voyager a while ago and just found it has a severe
issue... Once I power it on, after a few minutes the overall pitch can
change dramatically and intermittently for a fraction of a moment and than
return to normal. I can happen after a few minutes or after half an hours
after powering it, and it can come and go spontaneously. It can be heard
when using MIDI or the keyboard, and it happens also when the pitch wheel
is disabled.

Please take a look at this video, of an RME acting exactly the same as mine:

http://www.youtube.com/watch?v=Ew5DQXc-xko

The guy there says it was sent to moog for repair a few times and it still
acts the same... Can anyone think of any idea what causes it ?

The voltages are stable and when the pitch changes no change in the main
voltages is observed. All connectors and ICs are tightened in place... All
functions performs well and all pots are in good contact...

The only irregular thing I notices was that the 4 transistors on the small
powersupply board (not the main PS board) are very (very) hot. No heatsink
was built around them, just thought one of them might have gone bad but
again, all voltages are pretty accurate.

Will appreciate any help.

--bcaec50406ec864d5e04dc5c0f81
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div class=3D"gmail_quote"><div dir=3D"rtl"><div dir=3D"lt=
r">Hi all !<br><br></div><div dir=3D"ltr">I bought a second hand Voyager a =
while ago and just found it has a severe issue... Once I power it on, after=
 a few minutes the overall pitch can change dramatically and intermittently=
 for a fraction of a moment and than return to normal. I can happen after a=
 few minutes or after half an hours after powering it, and it can come and =
go spontaneously. It can be heard when using MIDI or the keyboard, and it h=
appens also when the pitch wheel is disabled.<br>

<br>Please take a look at this video, of an RME acting exactly the same as =
mine:<br><br><a href=3D"http://www.youtube.com/watch?v=3DEw5DQXc-xko" targe=
t=3D"_blank">http://www.youtube.com/watch?v=3DEw5DQXc-xko</a><br><br></div>=
<div dir=3D"ltr">
The guy there says it was sent to moog for repair a few times and it still =
acts the same... Can anyone think of any idea what causes it ?<br>
<br></div><div dir=3D"ltr">The voltages are stable and when the pitch chang=
es no change in the main voltages is observed. All connectors and ICs are t=
ightened in place... All functions performs well and all pots are in good c=
ontact...<br>

<br></div><div dir=3D"ltr">The only irregular thing I notices was that the =
4 transistors on the small powersupply board (not the main PS board) are ve=
ry (very) hot. No heatsink was built around them, just thought one of them =
might have gone bad but again, all voltages are pretty accurate.<br>

<br></div><div dir=3D"ltr">Will appreciate any help.<br></div></div>
</div></div>

--bcaec50406ec864d5e04dc5c0f81--