Thank you, my knowledge on electricity and powering is so close to zero that I had to post an obvious question
I will come back if interesting results will arise
Best wishes

> Il giorno 20 giu 2018, alle ore 09:58, yahoo@... 1 < 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@...
>> 1 < 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 ]
>> Gesendet: Dienstag, 12. Juni 2018 19:43
>> An: Doepfer_a100@yahoogroups.com
>> Betreff: Re: 1 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@...
>>
>> 1 < 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@...
>> 1 <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@...
>>
>> 1 < 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
>>
>> 1
>>
>> Gesendet: Dienstag, 12. Juni 2018 14:06
>> An: Doepfer_a100@yahoogroups.com
>> Betreff: Re: 1 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@... 1 < 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@... 1
>>
>> < 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 ]
>>
>> Gesendet: Montag, 11. Juni 2018 15:09
>> An: Doepfer_a100@yahoogroups.com
>> Betreff: 1 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
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>>
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>>
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>> Posted by: Diego Ragnini < diegora@... >
>> ------------------------------------
>>
>>
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>>
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
> ------------------------------------
>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>