Doepfer

hi guys,
got an A100 mini system the other week with the midi/cv convertor in 
it.
there seems to be a problem in that the cv and gate information is 
not being transferred to the internal buss as the VCOs or ADSR wont 
play unless hardwired with patch leads from the front panel. when 
this is done they all work fine for both gate and pitch.
ive checked the internal jumpers and these are in place but am at a 
loss with what to do next.
am i missing something obvious or does the midi/cv convertor not 
work in this way.
its driving me mad although thankfully i can work round it.
any suggestions would be much appreciated

Hi Neil,

> ive checked the internal jumpers and these are in place but am at a 
> loss with what to do next.

I take you mean those in the middle of the busbar running across the 
back of the case(?). However there are other places these signals can 
be 'cut': on the A-190 by the bus conector there are two links which 
can be cut (page 4 of manual), and the A-140 has a separate jumper to 
disconnect it from the gate on the bus (also page 4 of its manual 
entry), but since you are not getting CV into the A-110s I'd suspect 
the former (there is no independent mechanism in the A-110 to 
disconnect it from the bus). Can't think of anything else at the 
moment, but I'm sure others will come to the rescue if there is...

Tim

tim, 


thanks a million for your reply.
i went back inside the A100 armed with your info and some ideas it 
had created.
i had previously checked the links on the A190 also before posting.
the jumper however on the ADSR unit was indeed missing as you had 
suggsted so i put one on and problem solved. doh !!!!
with regards to the a110 VCOs,
i had a close inspection of the units and the PCBs, after about 15 
minutes of scrutinising i noticed two boxes printed and labelled int 
cv. one at the bottom right handside, near to the blue adjustment VR 
and the other at the top left near to where the mini jack for cv 
comes in.
these were both unconnected to anything and had clearly never been 
(holes were perfectly clean, no old solder traces etc) and it was 
the same on all three VCOs.
as an experiment i wired them together on one of the units and hey 
presto, full cv response.
can anyone confirm that these points should in actual fact have a 
wire conencting them together before i go ahead and connect and 
solder them properly.
i suspect so but just would like to check.

cheers,
neil

hello,
did you check the metal links in the a190 PCB???these
should be ok in order for the a190 to send cv/gate
signals to the bussboard.
bakis.


--- "neilwight <neilwight@yahoo.co.uk>"
<neilwight@yahoo.co.uk> wrote:
> hi guys,
> got an A100 mini system the other week with the
> midi/cv convertor in 
> it.
> there seems to be a problem in that the cv and gate
> information is 
> not being transferred to the internal buss as the
> VCOs or ADSR wont 
> play unless hardwired with patch leads from the
> front panel. when 
> this is done they all work fine for both gate and
> pitch.
> ive checked the internal jumpers and these are in
> place but am at a 
> loss with what to do next.
> am i missing something obvious or does the midi/cv
> convertor not 
> work in this way.
> its driving me mad although thankfully i can work
> round it.
> any suggestions would be much appreciated
> 
> 


=====
synthfreak(parallel worlds)
athens-greece
[Doepfer_a100] group owner-moderator

__________________________________________________
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hi neil,
i don't know about all these connections in the a110
pcb's ,but in anyway if you have bought the minisystem
new from doepfer the a190 should send gate to the
a140's(the a140 jumpers should be in place...)and also
the a110 should receive the cv signals.
so,if you have any doubts,contact dieter doepfer
direct!
 bakis.



--- "neilwight <neilwight@yahoo.co.uk>"
<neilwight@yahoo.co.uk> wrote:
> tim, 
> 
> 
> thanks a million for your reply.
> i went back inside the A100 armed with your info and
> some ideas it 
> had created.
> i had previously checked the links on the A190 also
> before posting.
> the jumper however on the ADSR unit was indeed
> missing as you had 
> suggsted so i put one on and problem solved. doh
> !!!!
> with regards to the a110 VCOs,
> i had a close inspection of the units and the PCBs,
> after about 15 
> minutes of scrutinising i noticed two boxes printed
> and labelled int 
> cv. one at the bottom right handside, near to the
> blue adjustment VR 
> and the other at the top left near to where the mini
> jack for cv 
> comes in.
> these were both unconnected to anything and had
> clearly never been 
> (holes were perfectly clean, no old solder traces
> etc) and it was 
> the same on all three VCOs.
> as an experiment i wired them together on one of the
> units and hey 
> presto, full cv response.
> can anyone confirm that these points should in
> actual fact have a 
> wire conencting them together before i go ahead and
> connect and 
> solder them properly.
> i suspect so but just would like to check.
> 
> cheers,
> neil
> 
> 
> 


=====
synthfreak(parallel worlds)
athens-greece
[Doepfer_a100] group owner-moderator

__________________________________________________
Do you Yahoo!?
Yahoo! Tax Center - forms, calculators, tips, more
http://taxes.yahoo.com/

Hi Neil,

> with regards to the a110 VCOs,
> i had a close inspection of the units and the PCBs, after about 15 
> minutes of scrutinising i noticed two boxes printed and labelled 
int 
> cv. one at the bottom right handside, near to the blue adjustment 
VR 
> and the other at the top left near to where the mini jack for cv 
> comes in.
> these were both unconnected to anything and had clearly never been 
> (holes were perfectly clean, no old solder traces etc) and it was 
> the same on all three VCOs.
> as an experiment i wired them together on one of the units and hey 
> presto, full cv response.
> can anyone confirm that these points should in actual fact have a 
> wire conencting them together before i go ahead and connect and 
> solder them properly.
> i suspect so but just would like to check.

When I popped one of my A-110s out last night I only scanned the 
_top_ of the PCB for a jumper, like on the A-140, but didn't see one. 
It looks like the box next to the bus connector is a provision for a 
jumper, but Doepfer don't fit it (you'll notice one pad doesn't go 
anywhere, the other goes direct to the bus connector). On both my A-
110s there is a wire connecting these points on the underside of the 
PCB - if your stuff is second-hand, maybe the previous owner had 
removed them? That the wire is on the underside would also probably 
explain why the holes look 'clean'. So, yep, I'm sure that is the 
answer!

Tim

> It looks like the box next to the bus connector is a provision for 
a 
> jumper, but Doepfer don't fit it (you'll notice one pad doesn't go 

Indeed, if you go to Doepfer's site, under the A-110 module 
description you'll find a link to the service manual, which contains 
the schematic, and there is clearly shown said jumper, next to 'ST1' 
the bus connector!

Tim

I know this isn't the problem you've got but I just thought I'd 
mention that the a141 (VCADSR) doesn't respond to the internal 
CV/GATE bus, if you want it to check out my website where it 
explains how to do it.

http://www.angelfire.com/music5/a100/a141project.html


John.





--- In Doepfer_a100@yahoogroups.com, "neilwight <neilwight@y...>" 
<neilwight@y...> wrote:
> hi guys,
> got an A100 mini system the other week with the midi/cv convertor 
in 
> it.
> there seems to be a problem in that the cv and gate information is 
> not being transferred to the internal buss as the VCOs or ADSR 
wont 
> play unless hardwired with patch leads from the front panel. when 
> this is done they all work fine for both gate and pitch.
> ive checked the internal jumpers and these are in place but am at 
a 

> loss with what to do next.
> am i missing something obvious or does the midi/cv convertor not 
> work in this way.
> its driving me mad although thankfully i can work round it.
> any suggestions would be much appreciated

hi tim,
thanks for the help again. yeah its second hand so maybe it was 
removed for some project or other.
checked the schematics as suggested.
can i double check with you that i am correct in thinking that i 
need to replace the wire to connect the INT CV at ST1 to the INT CV 
beside BU2.
this seems to be the only place i have anything missing from. it 
would mean i would need to put in a wire of about 4 inches...ish.
the points on the INT CV box beside ST1 are connected on mine but 
there is nothing connecting this then onwards to up near BU2 (where 
the external cv jack input is situated).

does this mean that someones removed the long wire rather than 
removing a short link?
can you confirm that your a110s have a connection from ST1 to the 
int cv connection beside BU2.

thanks again. 
neil




--- In Doepfer_a100@yahoogroups.com, "Tim Stinchcombe 
<timothy@t...>" <timothy@t...> wrote:
> Hi Neil,
> 
> > with regards to the a110 VCOs,
> > i had a close inspection of the units and the PCBs, after about 
15 
> > minutes of scrutinising i noticed two boxes printed and labelled 
> int 
> > cv. one at the bottom right handside, near to the blue 
adjustment 
> VR 
> > and the other at the top left near to where the mini jack for cv 
> > comes in.
> > these were both unconnected to anything and had clearly never 
been 
> > (holes were perfectly clean, no old solder traces etc) and it 
was 
> > the same on all three VCOs.
> > as an experiment i wired them together on one of the units and 
hey 
> > presto, full cv response.
> > can anyone confirm that these points should in actual fact have 
a 
> > wire conencting them together before i go ahead and connect and 
> > solder them properly.
> > i suspect so but just would like to check.
> 
> When I popped one of my A-110s out last night I only scanned the 
> _top_ of the PCB for a jumper, like on the A-140, but didn't see 
one. 
> It looks like the box next to the bus connector is a provision for 
a 
> jumper, but Doepfer don't fit it (you'll notice one pad doesn't go 
> anywhere, the other goes direct to the bus connector). On both my 
A-
> 110s there is a wire connecting these points on the underside of 
the 
> PCB - if your stuff is second-hand, maybe the previous owner had 
> removed them? That the wire is on the underside would also 
probably 

> explain why the holes look 'clean'. So, yep, I'm sure that is the 
> answer!
> 
> Tim

Hi Neil,

Since your stuff is second-hand, and hence I/we don't know how old it 
is, we'd better just check that we have the same version 110 PCB - 
mine are marked 'VERS. 3 C 1997' on the underside (etched in the 
copper). However, from what you've described so far, I'm quite sure 
we are not a million miles apart..

> can i double check with you that i am correct in thinking that i 
> need to replace the wire to connect the INT CV at ST1 to the INT CV 
> beside BU2.

Yes.

> this seems to be the only place i have anything missing from. it 
> would mean i would need to put in a wire of about 4 inches...ish.
> the points on the INT CV box beside ST1 are connected on mine but 
> there is nothing connecting this then onwards to up near BU2 (where 
> the external cv jack input is situated).
> 
> does this mean that someones removed the long wire rather than 
> removing a short link?

Yes, I reckon so (unless for some reason Doepfer sell the mini-system 
in this config, which seems quite unlikely).

> can you confirm that your a110s have a connection from ST1 to the 
> int cv connection beside BU2.

Yes.

The signal path is this: the 'internal CV' on the bus is the second 
pair of pins down on the bus connector (see for example  manual entry 
p9 of the introductory chapter, section 3 'Signal Flow'); this goes 
to the 'int CV' pad nearest the edge of the board; the wire is 
soldered to this, the other end to the 'int CV' pad right next to the 
CV1 socket ('BU2'- BU for 'buchse'= socket/plug in German!?) - you 
will see this goes to the socket so that it makes contact when no 
jack is inserted, and gets broken when a jack _is_ inserted. On mine, 
the second pad of the 'int CV' next to the bus connector does not go 
anywhere - if a jumper _were_ installed, then the wire would be 
connected to this, so that adding/removing the jumper would 
make/break the link. You say these two _are_ connected on yours, I 
assume this means on the component side of the board? If so, then it 
will obviuosly not matter to which one you solder the wire!

If you are still unsure, you could email me off-list, and perhaps we 
could talk over the dog-and-bone?

Tim