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RE: [Doepfer_a100] A127 and the BOM

2015-09-22 by Janne Gson Berg

Input voltage should be 11, not 22. +/- 11V should be transformed to +/- 5V.

/Janne

To: Doepfer_a100@yahoogroups.com
From: Doepfer_a100@yahoogroups.com
Date: Tue, 22 Sep 2015 12:19:03 +0200
Subject: Re: [Doepfer_a100] A127 and the BOM


Thanks for that Nicholas! Most helpful!

Ernst

On Tue, Sep 22, 2015 at 11:45 AM, Nicholas Keller maq163x2@gmail.com [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote:

http://www.raltron.com/cust/tools/voltage_divider.asp

Insert the input voltage of 22, value of R1 (numbers only, 1K = 1000), and desired output voltage of 5 (to match range of other Doepfer LFOs) or 10....and press compute.






On Tuesday, September 22, 2015, achtung_999 heinrich.himmelwasser@gmail.com [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote:

Found this from a discussion in 2009:

"The LFO outputs are available at pin 7 (triangle) and pin 8 (rectangle) of
the TL084. 1k protection resistors should be used to connect these pins to
the additional sockets. And a simple voltage divider made of two resistors
is recommended for the rectangle output because pin 8 outputs about +/-11V
(i.e. ~ 22V overall voltage level).

Best wishes
Dieter Doepfer"

Is this also valid for the version 2?
And about the mentioned voltage divider: what values do you advise for these?

all the best,

Ernst








On Mon, Sep 21, 2015 at 2:09 PM, achtung_999 <heinrich.himmelwasser@gmail.com> wrote:
btw. I have a version 2

On Mon, Sep 21, 2015 at 2:09 PM, achtung_999 <;heinrich.himmelwasser@gmail.com> wrote:
Oh that would be excellent! Thanks!

Ernst

On Mon, Sep 21, 2015 at 10:59 AM, yahoo@doepfer.de [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote:
> Tomorrow I am picking up a used A127 from someone that sells it for a nice price.
> I am of course looking at the BOM module also..
> One HUGE question remains though:
> why are the LFO outputs left off the BOM module?
> Seems like a pretty strange omission to me...
>
>
> Ernst

Of course the signals of the LFOs are available on the pc boards. But we would have to increase the width of the front panel to add
the LFO outputs. If you want to built your own breakout module I can tell you the corresponding solder points on the A-127 pcb.

Best wishes
Dieter Doepfer




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