From yahoo Sent Fri, Mar 13th 2015, 08:53
From yahoo Sent Fri, Mar 13th 2015, 08:53
There seems to be indeed a small negative offset of one semitone at the transpose input (1/12V = 0.083V, 1.922V+0.083=2.005 which would be the correct value). But as the A-156 is able to process only positive voltages at the inputs and outputs the lowest semitone is missing. I took a look at the schematics (from 1997 :-). The transpose CV is attenuated by a trimming potentiometer (P3), buffered (TL062/IC4) and then connected to the ADC input of the processor. As the TL062 is used only for this task I suppose that it produces a small negative offset. I'd to replace the TL062 (or return the module if it's still under warranty for repair to the dealer where you purchased it). Another source of error could be the ADC input of the processor. Best wishes Dieter Doepfer > -----Ursprüngliche Nachricht----- > Von: xxxxxxx_xxxx@xxxxxxxxxxx.xxx [mailto:xxxxxxx_xxxx@xxxxxxxxxxx.xxx] > Gesendet: Donnerstag, 12. März 2015 17:37 > An: xxxxxxx_xxxx@xxxxxxxxxxx.xxx > Betreff: Re: [Doepfer_a100] A-156 Dual Quantizer Transpose issue > > > > > I did some further measurements: > > I used the upper quantizer for this. > > CV In: 2.000 V gives CV Out: 1.922 V > > Then with Transpose In > > 1.001 V gives CV Out: 2.836 V > 2.003 V gives CV Out: 3.834 V > 3.000 V gives CV Out: 4.828 V > > Strange. > > Karel. ------------------------------------ ------------------------------------ ------------------------------------ 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! ID required) <*> To change settings via email: xxxxxxx_xxxx-xxxxxx@xxxxxxxxxxx.xxx xxxxxxx_xxxx-xxxxxxxxxxxx@xxxxxxxxxxx.xxx <*> To unsubscribe from this group, send an email to: xxxxxxx_xxxx-xxxxxxxxxxx@xxxxxxxxxxx.xxx <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/