Doepfer

the lower section of my a-156 is just putting out a steady 1.76 volts. i have the jumper set so the upper section is affected by the switches on the lower section, but the lower section doesn't work with the jumper in either position. the upper section works. any suggestions? it was working a few days ago, i don't think i did anything wrong to it.  thanks very much.

Make sure all the socketted ICs are firmly pushed in. Also make sure that all the jack sockets are making good contact with your patch leads. The two signal paths share parts of the three main ICs, so I'm thinking that if they work for one section, then why not for the other, so it might just be something simple...

Tim
__________________________________________________________
Tim Stinchcombe 

Cheltenham, Glos, UK
www.timstinchcombe.co.uk

--- In Doepfer_a100@yahoogroups.com, "goodnessgrows" <goodnessgrows@...> wrote:

>
> the lower section of my a-156 is just putting out a steady 1.76 volts. i have the jumper set so the upper section is affected by the switches on the lower section, but the lower section doesn't work with the jumper in either position. the upper section works. any suggestions? it was working a few days ago, i don't think i did anything wrong to it.  thanks very much.
>

thanks tim.  after messing around with it some more, it is behaving differently, but still strangely.  now the lower quantizer works as the upper one does, except with nothing plugged in the input it gives a steady 1.84 volts.  when a signal is introduced to the input jack, it will give quantized voltages above 1.84 volts, but not below.  weird.



--- In Doepfer_a100@yahoogroups.com, "Tim" <timothy@...> wrote:

>
> Make sure all the socketted ICs are firmly pushed in. Also make sure that all the jack sockets are making good contact with your patch leads. The two signal paths share parts of the three main ICs, so I'm thinking that if they work for one section, then why not for the other, so it might just be something simple...
> 
> Tim
> __________________________________________________________
> Tim Stinchcombe 
> 
> Cheltenham, Glos, UK
> www.timstinchcombe.co.uk
> 
> --- In Doepfer_a100@yahoogroups.com, "goodnessgrows" <goodnessgrows@> wrote:
> >
> > the lower section of my a-156 is just putting out a steady 1.76 volts. i have the jumper set so the upper section is affected by the switches on the lower section, but the lower section doesn't work with the jumper in either position. the upper section works. any suggestions? it was working a few days ago, i don't think i did anything wrong to it.  thanks very much.
> >
>

> the lower section of my a-156 is just putting out a steady 1.76
> volts. i have the jumper set so the upper section is affected by
> the switches on the lower section, but the lower section doesn't
> work with the jumper in either position. the upper section works.
> any suggestions? it was working a few days ago, i don't think i
> did anything wrong to it.  thanks very much.

Difficult to find out what's wrong. As the upper section is OK it could be
one of these:

defective OpAmp (TLC274)
defective DAC (TLC5620)
contact problem of the trig in socket: an internal trigger signal is fed to
the switching contacts of the trig in sockets, if this signal is interrupted
because of a faulty switching contact the quantize will stop (if the
quantization works with an external trigger it's probably a problem with the
switching contact of the trig in socket)

Best wishes
Dieter Doepfer