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A-156 input threshold tracking

A-156 input threshold tracking

2018-06-01 by John Hollis

Hi Dieter,

I am using 4 x A-156 together. The input threshold tracking is usable but a bit tricky with one of the modules being slightly different. I have read the A-156 adjustment guide and have the correct tools to hand. I understand how P1, P2 and P3 adjust the input scale but would like to understand if recalibrating them might help with a little input offset. Any thoughts appreciated.

Many thanks for your time and attention.

Kind Regards,

John Hollis

AW: [Doepfer_a100] A-156 input threshold tracking

2018-06-04 by yahoo@doepfer.de

Hello,

unfortunately there is no offset trimming available at the A-156 module. P1,
P2 and P3 are just attenuators (with buffers) but do not offer an offset
feature. One would have to add an offset externally or modify the A-156 (by
adding trimming potentiometers and resistors for offset adjustment). I can
tell you details if required.

Best wishes
Dieter Doepfer
Show quoted textHide quoted text
> -----Ursprungliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> Gesendet: Freitag, 1. Juni 2018 19:33
> An: yahoo@doepfer.de [Doepfer_a100]
> Betreff: [Doepfer_a100] A-156 input threshold tracking
>
>
> Hi Dieter,
>
> I am using 4 x A-156 together. The input threshold tracking is
> usable but a bit tricky with one of the modules being slightly
> different. I have read the A-156 adjustment guide and have the
> correct tools to hand. I understand how P1, P2 and P3 adjust the
> input scale but would like to understand if recalibrating them
> might help with a little input offset. Any thoughts appreciated.
>
> Many thanks for your time and attention.
>
> Kind Regards,
>
> John Hollis

Re: [Doepfer_a100] A-156 input threshold tracking

2018-06-12 by John Hollis

Hi Dieter,

Thanks for your response. I have now had a chance to pull an A-156 out of the rack. From what I can see it looks like that TLC274 is the input buffer. If that chip has a 10mV offset I was wondering if it might be worth swapping out the TLC264 for something like an LT1014 (150uV offset).

Do you think it’s worth trying or am I doomed to get the soldering iron out?

Best wishes
John
Show quoted textHide quoted text
> On 4 Jun 2018, at 09:47, yahoo@doepfer.de [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote:
> 
> Hello,
> 
> unfortunately there is no offset trimming available at the A-156 module. P1,
> P2 and P3 are just attenuators (with buffers) but do not offer an offset
> feature. One would have to add an offset externally or modify the A-156 (by
> adding trimming potentiometers and resistors for offset adjustment). I can
> tell you details if required.
> 
> Best wishes
> Dieter Doepfer
> 
> > -----Ursprungliche Nachricht-----
> > Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> > Gesendet: Freitag, 1. Juni 2018 19:33
> > An: yahoo@doepfer.de [Doepfer_a100]
> > Betreff: [Doepfer_a100] A-156 input threshold tracking
> >
> >
> > Hi Dieter,
> >
> > I am using 4 x A-156 together. The input threshold tracking is
> > usable but a bit tricky with one of the modules being slightly
> > different. I have read the A-156 adjustment guide and have the
> > correct tools to hand. I understand how P1, P2 and P3 adjust the
> > input scale but would like to understand if recalibrating them
> > might help with a little input offset. Any thoughts appreciated.
> >
> > Many thanks for your time and attention.
> >
> > Kind Regards,
> >
> > John Hollis
> 
> 
>

AW: [Doepfer_a100] A-156 input threshold tracking

2018-06-12 by yahoo@doepfer.de

Yes, two of the opamps of the TLC274 are the input buffers. You may try it
out but from my point of view it would be more reasonable to add an offset
circuit (trimming potentiometer + resistor) than to try out to find another
opamp with a different offset.

Best wishes
Dieter Doepfer
Show quoted textHide quoted text
> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> Gesendet: Dienstag, 12. Juni 2018 10:45
> An: Doepfer_a100@yahoogroups.com
> Betreff: Re: [Doepfer_a100] A-156 input threshold tracking
>
>
> Hi Dieter,
>
> Thanks for your response. I have now had a chance to pull an
> A-156 out of the rack. From what I can see it looks like that
> TLC274 is the input buffer. If that chip has a 10mV offset I was
> wondering if it might be worth swapping out the TLC264 for
> something like an LT1014 (150uV offset).
>
> Do you think it’s worth trying or am I doomed to get the
> soldering iron out?
>
> Best wishes
> John
>
> > On 4 Jun 2018, at 09:47, yahoo@doepfer.de [Doepfer_a100]
> <Doepfer_a100@yahoogroups.com> wrote:
> >
> > Hello,
> >
> > unfortunately there is no offset trimming available at the
> A-156 module. P1,
> > P2 and P3 are just attenuators (with buffers) but do not offer an offset
> > feature. One would have to add an offset externally or modify
> the A-156 (by
> > adding trimming potentiometers and resistors for offset
> adjustment). I can
> > tell you details if required.
> >
> > Best wishes
> > Dieter Doepfer
> >
> > > -----Ursprungliche Nachricht-----
> > > Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]
> > > Gesendet: Freitag, 1. Juni 2018 19:33
> > > An: yahoo@doepfer.de [Doepfer_a100]
> > > Betreff: [Doepfer_a100] A-156 input threshold tracking
> > >
> > >
> > > Hi Dieter,
> > >
> > > I am using 4 x A-156 together. The input threshold tracking is
> > > usable but a bit tricky with one of the modules being slightly
> > > different. I have read the A-156 adjustment guide and have the
> > > correct tools to hand. I understand how P1, P2 and P3 adjust the
> > > input scale but would like to understand if recalibrating them
> > > might help with a little input offset. Any thoughts appreciated.
> > >
> > > Many thanks for your time and attention.
> > >
> > > Kind Regards,
> > >
> > > John Hollis
> >
> >
> >
>
>
>
> ------------------------------------
> Posted by: John Hollis <john@hollis.co.uk>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>

Re: [Doepfer_a100] A-156 input threshold tracking

2018-06-16 by John Hollis

Hi Dieter,

I decided to try it and used the LT1014DN with an offset of 60uV. I now have 8 channels of pitch quantisation that track well. I would suggest it to anyone using multiple A-156 quantisers.

The limitation now appears to be the integrity of the patch cabling. If all the transpose input connections are clean the tracking is spot on.

Best wishes
John
Show quoted textHide quoted text
> On 12 Jun 2018, at 11:20, yahoo@doepfer.de [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote:
> 
> Yes, two of the opamps of the TLC274 are the input buffers. You may try it
> out but from my point of view it would be more reasonable to add an offset
> circuit (trimming potentiometer + resistor) than to try out to find another
> opamp with a different offset.
> 
> Best wishes
> Dieter Doepfer
> 
> 
>> -----Ursprüngliche Nachricht-----
>> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
>> Gesendet: Dienstag, 12. Juni 2018 10:45
>> An: Doepfer_a100@yahoogroups.com
>> Betreff: Re: [Doepfer_a100] A-156 input threshold tracking
>> 
>> 
>> Hi Dieter,
>> 
>> Thanks for your response. I have now had a chance to pull an
>> A-156 out of the rack. From what I can see it looks like that
>> TLC274 is the input buffer. If that chip has a 10mV offset I was
>> wondering if it might be worth swapping out the TLC264 for
>> something like an LT1014 (150uV offset).
>> 
>> Do you think it’s worth trying or am I doomed to get the
>> soldering iron out?
>> 
>> Best wishes
>> John
>> 
>>> On 4 Jun 2018, at 09:47, yahoo@doepfer.de [Doepfer_a100]
>> <Doepfer_a100@yahoogroups.com> wrote:
>>> 
>>> Hello,
>>> 
>>> unfortunately there is no offset trimming available at the
>> A-156 module. P1,
>>> P2 and P3 are just attenuators (with buffers) but do not offer an offset
>>> feature. One would have to add an offset externally or modify
>> the A-156 (by
>>> adding trimming potentiometers and resistors for offset
>> adjustment). I can
>>> tell you details if required.
>>> 
>>> Best wishes
>>> Dieter Doepfer
>>> 
>>>> -----Ursprungliche Nachricht-----
>>>> Von: Doepfer_a100@yahoogroups.com
>> [mailto:Doepfer_a100@yahoogroups.com]
>>>> Gesendet: Freitag, 1. Juni 2018 19:33
>>>> An: yahoo@doepfer.de [Doepfer_a100]
>>>> Betreff: [Doepfer_a100] A-156 input threshold tracking
>>>> 
>>>> 
>>>> Hi Dieter,
>>>> 
>>>> I am using 4 x A-156 together. The input threshold tracking is
>>>> usable but a bit tricky with one of the modules being slightly
>>>> different. I have read the A-156 adjustment guide and have the
>>>> correct tools to hand. I understand how P1, P2 and P3 adjust the
>>>> input scale but would like to understand if recalibrating them
>>>> might help with a little input offset. Any thoughts appreciated.
>>>> 
>>>> Many thanks for your time and attention.
>>>> 
>>>> Kind Regards,
>>>> 
>>>> John Hollis
>>> 
>>> 
>>> 
>> 
>> 
>> 
>> ------------------------------------
>> Posted by: John Hollis <john@hollis.co.uk>
>> ------------------------------------
>> 
>> 
>> ------------------------------------
>> 
>> Yahoo Groups Links
>> 
>> 
>> 
> 
> 
> 
> ------------------------------------
> 
> ------------------------------------
> 
> 
> ------------------------------------
> 
> Yahoo Groups Links
> 
> 
>

AW: [Doepfer_a100] A-156 input threshold tracking

2018-06-18 by yahoo@doepfer.de

Hello John,

thank you for the information. We have the LT1014 in stock and I'll try it
out.

Best wishes
Dieter Doepfer
Show quoted textHide quoted text
> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> Gesendet: Samstag, 16. Juni 2018 10:30
> An: Doepfer_a100@yahoogroups.com
> Betreff: Re: [Doepfer_a100] A-156 input threshold tracking
>
>
> Hi Dieter,
>
> I decided to try it and used the LT1014DN with an offset of 60uV.
> I now have 8 channels of pitch quantisation that track well. I
> would suggest it to anyone using multiple A-156 quantisers.
>
> The limitation now appears to be the integrity of the patch
> cabling. If all the transpose input connections are clean the
> tracking is spot on.
>
> Best wishes
> John
>
> > On 12 Jun 2018, at 11:20, yahoo@doepfer.de [Doepfer_a100]
> <Doepfer_a100@yahoogroups.com> wrote:
> >
> > Yes, two of the opamps of the TLC274 are the input buffers. You
> may try it
> > out but from my point of view it would be more reasonable to
> add an offset
> > circuit (trimming potentiometer + resistor) than to try out to
> find another
> > opamp with a different offset.
> >
> > Best wishes
> > Dieter Doepfer
> >
> >
> >> -----Ursprüngliche Nachricht-----
> >> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
> >> Gesendet: Dienstag, 12. Juni 2018 10:45
> >> An: Doepfer_a100@yahoogroups.com
> >> Betreff: Re: [Doepfer_a100] A-156 input threshold tracking
> >>
> >>
> >> Hi Dieter,
> >>
> >> Thanks for your response. I have now had a chance to pull an
> >> A-156 out of the rack. From what I can see it looks like that
> >> TLC274 is the input buffer. If that chip has a 10mV offset I was
> >> wondering if it might be worth swapping out the TLC264 for
> >> something like an LT1014 (150uV offset).
> >>
> >> Do you think it’s worth trying or am I doomed to get the
> >> soldering iron out?
> >>
> >> Best wishes
> >> John
> >>
> >>> On 4 Jun 2018, at 09:47, yahoo@doepfer.de [Doepfer_a100]
> >> <Doepfer_a100@yahoogroups.com> wrote:
> >>>
> >>> Hello,
> >>>
> >>> unfortunately there is no offset trimming available at the
> >> A-156 module. P1,
> >>> P2 and P3 are just attenuators (with buffers) but do not
> offer an offset
> >>> feature. One would have to add an offset externally or modify
> >> the A-156 (by
> >>> adding trimming potentiometers and resistors for offset
> >> adjustment). I can
> >>> tell you details if required.
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >>>
> >>>> -----Ursprungliche Nachricht-----
> >>>> Von: Doepfer_a100@yahoogroups.com
> >> [mailto:Doepfer_a100@yahoogroups.com]
> >>>> Gesendet: Freitag, 1. Juni 2018 19:33
> >>>> An: yahoo@doepfer.de [Doepfer_a100]
> >>>> Betreff: [Doepfer_a100] A-156 input threshold tracking
> >>>>
> >>>>
> >>>> Hi Dieter,
> >>>>
> >>>> I am using 4 x A-156 together. The input threshold tracking is
> >>>> usable but a bit tricky with one of the modules being slightly
> >>>> different. I have read the A-156 adjustment guide and have the
> >>>> correct tools to hand. I understand how P1, P2 and P3 adjust the
> >>>> input scale but would like to understand if recalibrating them
> >>>> might help with a little input offset. Any thoughts appreciated.
> >>>>
> >>>> Many thanks for your time and attention.
> >>>>
> >>>> Kind Regards,
> >>>>
> >>>> John Hollis
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >> ------------------------------------
> >> Posted by: John Hollis <john@hollis.co.uk>
> >> ------------------------------------
> >>
> >>
> >> ------------------------------------
> >>
> >> Yahoo Groups Links
> >>
> >>
> >>
> >
> >
> >
> > ------------------------------------
> >
> > ------------------------------------
> >
> >
> > ------------------------------------
> >
> > Yahoo Groups Links
> >
> >
> >
>
>
> ------------------------------------
> Posted by: John Hollis <john@hollis.co.uk>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>

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