From yahoo Sent Tue, Jun 12th 2018, 13:57
From yahoo Sent Tue, Jun 12th 2018, 13:57
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 xxxxxxx@xxxx.xx > [Doepfer_a100] <xxxxxxx_xxxx@xxxxxxxxxxx..xxx> 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, xxxxx@xxxxxxx.xx > [Doepfer_a100] <xxxxxxx_xxxx@xxxxxxxxxxx.xxx> 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: xxxxxxx_xxxx@xxxxxxxxxxx.xxx > [mailto:xxxxxxx_xxxx@xxxxxxxxxxx..xxx] > >> Gesendet: Dienstag, 12. Juni 2018 14:06 > >> An: xxxxxxx_xxxx@xxxxxxxxxxx.xxx > >> 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 > >> xxxx@xxxxxx.xx.xx [Doepfer_a100] <xxxxxxx_xxxx@xxxxxxxxxxx.xxx> > >> 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, xxxxx@xxxxxxx.xx [Doepfer_a100] > >> <xxxxxxx_xxxx@xxxxxxxxxxx.xxx> 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: xxxxxxx_xxxx@xxxxxxxxxxx.xxx > > [mailto:xxxxxxx_xxxx@xxxxxxxxxxx.xxx] > >>> Gesendet: Montag, 11. Juni 2018 15:09 > >>> An: xxxxxxx_xxxx@xxxxxxxxxxx.xxx > >>> 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 > >> > >> > >> > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------ > > > > ------------------------------------ > > > > > > ------------------------------------ > > > > Yahoo Groups Links > > > > > > > > > > > > ------------------------------------ ------------------------------------ ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Doepfer_a100/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Doepfer_a100/join (Yahoo! 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