[sdiy] Juno 6 voice problem

Andrew Simper andy at cytomic.com
Tue Jul 9 06:25:14 CEST 2013


Hi Travis,

Before you go swapping chips you should check the gate signal heading
to the env chip and make sure that is correct. One way to do this is
switch the amp to gate mode instead of env and have a listen,
otherwise poke around the gate outputs of IC50 to check all is well.
Andy
--
cytomic - sound music software
mobile: +61-450-774-230
skype: andrewsimper



On 9 July 2013 12:16, Travis Thatcher <recompas at gmail.com> wrote:
> Thanks Andrew. I started looked at the env signals at tp6 on my scope and it
> looks like the envelope output for voice 2 does not reflect the envelope
> settings, rather it just appears to be on. I'm going to try to swap the env
> chip as Doug suggested tomorrow and see what happens. If that doesn't work
> I'll start from the 662.
>
> Thanks guys for the help so far!
>
>
> On Mon, Jul 8, 2013 at 11:10 PM, Andrew Simper <andy at cytomic.com> wrote:
>>
>> Hi Travis,
>>
>> If the VCA is being kept high you need to check the control voltage
>> being sent to it and see how it compares to the other voices. TP6 will
>> check IR3R01 envelope chip is working, when you say tp6 "goes high"
>> does it also go low again? If not then it may be a problem with the
>> gate signal heading to the env chip.
>>
>> If it does go low then I would work backwards from pin 1 of the ba662
>> ic24.25.21.22.19.20, until you can find a difference to the other
>> voices. If there is no difference at pin 1 then your ba662 could be
>> the problem.
>>
>> Andy
>> --
>> cytomic - sound music software
>>
>>
>>
>> On 9 July 2013 00:02, Travis Thatcher <recompas at gmail.com> wrote:
>> > I'm looking at a Juno 6 for a buddy who has a voice issue. The
>> > envelope on Voice 2 seems to be always on. If I bring up the release
>> > on the envelope it opens up the filter for that voice and you can hear
>> > the oscillator drone. I tested the output for that voice on tp6 and it
>> > goes high when that voice is triggered.  I'm guessing this would be a
>> > vca issue? Anybody have any ideas on where next to dig in? I was going
>> > to make sure the vca gain trimmer was okay first - since the one that
>> > is there different from the other voices and may have been replaced at
>> > some point.  After that I was thinking the transistors associated with
>> > the vca (tr5-8).  Any pointers on how to better pinpoint the issue
>> > would be really helpful.
>> >
>> > Thanks!
>> >
>> >
>> > --
>> > http://www.travisthatcher.com
>> > http://www.soundcloud.com/travisthatcher
>> > http://voiceofsaturn.blogspot.com
>> > _______________________________________________
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>
>
>
>
> --
> http://www.travisthatcher.com
> http://www.soundcloud.com/travisthatcher
> http://voiceofsaturn.blogspot.com


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