Doepfer

Thank you Florian, as usual very available and helpful
So, if I use brand new mono Doepfer cables and the R2M black box is connected via these cables to A-100 systems which are properly grounded then everything should be fine, right?

What happens if one provides an external wire to connect the black box to the ground/earth (not too differently from what I will do for the A-100LC3 cases)?

Does the ground uses the “tip” of the cable?

The MS20 also shows a 1/4 female jack labelled “GND": how do I use this? And is it always the tip providing the connection?

Best, Diego

> Il giorno 28 giu 2018, alle ore 23:33, Florian Anwander fanwander@mnet-online.de [Doepfer_a100] <Doepfer_a100@yahoogroups.com> ha scritto:
> 
> No, you should not. But you have to reassure, that the ground connection 
> is provided by the 3.5mm cables between the R2M control box and the 
> A-100. Do NOT(!) use 3.5mm cables with stereo sockets!!!
> 
> On 28.06.18 18:58 , Diego Ragnini diegora@free.fr <mailto:diegora@free.fr> [Doepfer_a100] wrote:
> > Hello,
> > regarding the floating GND matter, has the Ribbon R2M control box a floating ground as well? In other terms, do I have to connect the black box metal frame to the ground/earth?
> >
> > Best, Diego
> >
> >> Il giorno 20 giu 2018, alle ore 09:58, yahoo@doepfer.de <mailto:yahoo@doepfer.de> [Doepfer_a100]<Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> ha scritto:
> >>
> >> Yes, these are the correct terminals. If the GND connection really solves
> >> the problems one has to think about a permanent solution. But I have never
> >> heard about similar problems from other customers. And we use A-100P9
> >> together with A-100LC3 during exhibitions or work shops and never had any
> >> problems.
> >>
> >> Best wishes
> >> Dieter Doepfer
> >>
> >>
> >>> Please can someone check that this would be the right connection
> >>> in order to grant that the A-100LC3 “GND” is temporarily
> >>> connected to mains earth/GND? So I would temporarily connect the
> >>> blade terminal of the first picture to the same blade terminal
> >>> found in the A-100P9 (2nd picture).. Then, in order to set a
> >>> definitive connection, I would provide a mains “plug" where to
> >>> pass uniquely cables for all floating GND's in the system towards
> >>> the mains earth/GND pin wall socket. Would both these solutions
> >>> be correct, please?
> >>> Best, Diego
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Il giorno 13 giu 2018, alle ore 09:53, yahoo@doepfer.de <mailto:yahoo@doepfer.de>
> >>> [Doepfer_a100]<Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> ha scritto:
> >>>
> >>>
> >>> It's not for sure that this is the reason for your problems. So I'd
> >>> recommend just to try it out, i.e. connect the GND of the A-100LC3
> >>> temporarily (e.g. the GND blade terminal on the A-100 bus board) to GND of
> >>> the other devices included in the signal path. If you use an A-100LC6
> >>> (mentioned in the subject of your message) that not necessary as the
> >>> A-100LC6 GND is connected to mains earth/GND.
> >>>
> >>> Does the problem also occur if you use the A-138s outputs
> >>> directly (without
> >>> the buffered multiple)?
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >>>
> >>>
> >>> -----Ursprüngliche Nachricht-----
> >>> Von: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com> [mailto:Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>]
> >>> Gesendet: Dienstag, 12. Juni 2018 19:43
> >>> An: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>
> >>> Betreff: Re: [Doepfer_a100] Interferences from A-138s into LC6
> >>>
> >>>
> >>> Ok thanks, so I have to learn how to ground it !
> >>> It seems obvious but not
> >>> I will try
> >>>
> >>> Floating GND (?) needs to be deepened
> >>> Or I’d better search for someone who can do it?
> >>>
> >>>
> >>>
> >>> Il giorno 12 giu 2018, alle ore 15:57, yahoo@doepfer.de <mailto:yahoo@doepfer.de>
> >>>
> >>> [Doepfer_a100]<Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> ha scritto:
> >>>
> >>>
> >>> I fully agree. As the A-100LC3 also uses an external power
> >>>
> >>> supply it's GND
> >>>
> >>> is not connected to mains earth/GND and has the mentioned
> >>>
> >>> "floating GND" (in
> >>>
> >>> contrast to all other A-100 cases).
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >>>
> >>>
> >>> Definitely get that case properly earthed first. Even if its not
> >>> causing this issue, its not safe for you or your equipment. There
> >>> should be a both crimped and soldered lug on the metal case, held
> >>> in good contact with a screw and washers which connects to earth..
> >>> This probably can be done by connecting the PSU ground to the
> >>> case, but its worth checking that the case actually is
> >>> electrically connected to the ground pin on your wall socket.
> >>> Some PSUs with external bricks have a floating ground
> >>>
> >>>
> >>> On 12 Jun 2018, at 14:20, Diego Ragnini diegora@free.fr <mailto:diegora@free.fr>
> >>> [Doepfer_a100]<Doepfer_a100@yahoogroups..com> wrote:
> >>>
> >>>
> >>>
> >>> Thanks, the cables are all recent doepfer
> >>> Not sure to know how to do this experiment though I will try.
> >>> Which GND do you refer to?
> >>> Just the one of the audio 2 (the source which feeds the A138s) or
> >>> the multed audio 1 as well?
> >>> Audio 2 is from a DPO mounted on a A-100P9 PSU3
> >>> Audio 1 is from a Bastl Instruments SoftPop, which in the
> >>> meanwhile went back to the dealer to be replaced for another kind
> >>> of issue. I had noticed some electricity at fingers while
> >>> touching the side panels of its case. It probably is not properly
> >>> grounded, though it shows some sockets for grounding...
> >>>
> >>> Best wishes,
> >>> Diego
> >>>
> >>>
> >>> Il giorno 12 giu 2018, alle ore 14:54, yahoo@doepfer.de <mailto:yahoo@doepfer.de>
> >>>
> >>> [Doepfer_a100]<Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> ha scritto:
> >>>
> >>>
> >>> As external audio signals are involved it maybe a grounding
> >>>
> >>> problem. Make
> >>>
> >>> sure that the cables that are used to connect the modules to
> >>>
> >>> the external
> >>>
> >>> signals carry GND (there are patch cables available without
> >>>
> >>> GND, as long as
> >>>
> >>> one patches within the case no problems occur, but with
> >>>
> >>> external signals the
> >>>
> >>> GND is missing). And I don't know if all WMD sockets are
> >>>
> >>> grounded. In some
> >>>
> >>> modules (yes, also in some older A-100 modules :-) the GND of
> >>>
> >>> some sockets
> >>>
> >>> is not connected as it does not matter if all modules are
> >>>
> >>> connected to the
> >>>
> >>> same GND.
> >>> You may try also the following: connect the GND of the A-100LC3
> >>>
> >>> temporarily
> >>>
> >>> to the GND of the signal source unit (at the A-100LC3 there
> >>>
> >>> should be an
> >>>
> >>> unused GND terminal on the bus board). If then the problem
> >>>
> >>> disappears it's a
> >>>
> >>> grounding issue.
> >>> It's just an idea. Not sure if this is the reason.
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >>>
> >>>
> >>>
> >>> -----Ursprüngliche Nachricht-----
> >>> Von: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>
> >>>
> >>> [mailto:Doepfer_a100@yahoogroups..com]
> >>>
> >>> Gesendet: Dienstag, 12. Juni 2018 14:06
> >>> An: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>
> >>> Betreff: Re: [Doepfer_a100] Interferences from A-138s into LC6
> >>>
> >>>
> >>>
> >>>
> >>> Hi thanks everybody for replying
> >>> The situation was vague indeed, sorry, though the patch is very basic
> >>> The case is just 1 row (LC3)
> >>> As you can see by the colours on the following screenshot, the
> >>> multed audio 1 signal (red cable) is slightly affected by the
> >>> audio 2 signal (blue cable), as we turn CW the A-138s channel
> >>>
> >>> volume knob.
> >>>
> >>>
> >>>
> >>> Nothing else is patched/ engaged.
> >>>
> >>>
> >>> I unfortunately have no means nor expertise for measuring anything...
> >>> ASAP I will first try installing the multiple on another case.
> >>>
> >>>
> >>> Best, Diego
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Il giorno 12 giu 2018, alle ore 10:25, John Hollis
> >>> john@hollis.co.uk <mailto:john@hollis.co.uk> [Doepfer_a100]<Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>>
> >>> ha scritto:
> >>>
> >>>
> >>> Hi Diego,
> >>>
> >>> It does sound like there might be a short between the adjacent
> >>> modules. Can you check for that?
> >>>
> >>> Thanks
> >>> John
> >>>
> >>>
> >>> On 12 Jun 2018, at 08:57, yahoo@doepfer.de <mailto:yahoo@doepfer.de> [Doepfer_a100]
> >>>
> >>> <Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> wrote:
> >>>
> >>>
> >>> Hello,
> >>>
> >>> the A-138s is a very simple module (just a standard mixer
> >>>
> >>> circuit with
> >>>
> >>> operational amplifiers) and I have no idea how the signal could
> >>>
> >>> crosstalk to
> >>>
> >>> any other module.
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >>>
> >>>
> >>> -----Ursprungliche Nachricht-----
> >>> Von: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>
> >>>
> >>> [mailto:Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>]
> >>>
> >>> Gesendet: Montag, 11. Juni 2018 15:09
> >>> An: Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>
> >>> Betreff: [Doepfer_a100] Interferences from A-138s into LC6
> >>>
> >>>
> >>> Hello, I have a WMD buffered multiple which suffers from A-138s
> >>> mixer interferences, both powered by an LC6 Doepfer case. Is the
> >>> WMD faulty or its cable? A-138s output can be heard on the WMD,
> >>> unless knob's fully CCW. I also see that the multed signal is
> >>> louder that the original one. Any hint is welcome.
> >>>
> >>> Best regards,
> >>> Diego
> >>>
> >>>
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> >>> Yahoo Groups Links
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> >>> ------------------------------------
> >>> Posted by: Diego Ragnini<diegora@free.fr <mailto:diegora@free.fr>>
> >>> ------------------------------------
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> >>> Yahoo Groups Links
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> >>
> >>
> >> ------------------------------------
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> >> Yahoo Groups Links
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> >>
> >
> >
> > ------------------------------------
> > Posted by: Diego Ragnini<diegora@free.fr <mailto:diegora@free.fr>>
> > ------------------------------------
> >
> >
> > ------------------------------------
> >
> > Yahoo Groups Links
> >
> >
> >
> 
> 
>