Doepfer

I have an A-137 and A-110 in a DIY #1 kit, mounted in a wooden case. 
For power, it uses a 120v->16v AC adaptor, that has two wires going
into the DIY #1's power supply, then it goes into the power bus.  I
don't have the proper mono wiring yet, but used some 3.5mm stereo
patch cables to patch some stuff through the 137, and also ran the 110
into the 137, just as a test to see how it sounds.  And there's a
noticeable hum on this thing.  I'm not at home right now, at a buddy's
house playing with the thing, so I don't know if it's maybe just his
power.  Otherwise, it's either the stereo cables (I don't see why), or
this thing just has a hum problem.  Could it be because it's not
grounded?  Any suggestions?


Also, once I get the A-110 and A-190 hooked up, will it be playing the
right notes when I hit a key?  (are they somehow tuned at the
factory?)  Or is that what the tune knob is for on the front?  Thanks!

You find my answers written inline.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von techmaster242
> Gesendet: Sonntag, 27. Juli 2008 23:00
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] DIY #1 humming?
>
>
> I have an A-137 and A-110 in a DIY #1 kit, mounted in a wooden case.
> For power, it uses a 120v->16v AC adaptor, that has two wires going
> into the DIY #1's power supply, then it goes into the power bus.

How many mA output current has the adapter. It should have 2500mA to obtain
the same power as the PSUII (1250mA).
At least twice the current sum of the installed modules is necessary (e.g.
sum of all module = 450 mA -> minimum current of the adapter = 900 mA)

> I don't have the proper mono wiring yet, but used some 3.5mm stereo
> patch cables to patch some stuff through the 137, and also ran the 110
> into the 137, just as a test to see how it sounds.  And there's a
> noticeable hum on this thing.  I'm not at home right now, at a buddy's
> house playing with the thing, so I don't know if it's maybe just his
> power.  Otherwise, it's either the stereo cables (I don't see why), or
> this thing just has a hum problem.  Could it be because it's not
> grounded?  Any suggestions?

Additional grounding may help. But normally the system is grounded as soon
as one of the modules is connected to your mixer.

> Also, once I get the A-110 and A-190 hooked up, will it be playing the
> right notes when I hit a key?  (are they somehow tuned at the
> factory?)  Or is that what the tune knob is for on the front?  Thanks!

The factory setting for the A-190 is Midi channel 1, Midi reference note 36
The factory setting for the A-110 is 32.7 Hz (C1) with 0V CV and octave
switch in position #3

--- In Doepfer_a100@yahoogroups.com, <hardware@...> wrote:
>
> You find my answers written inline.
> 
> Best wishes
> Dieter Doepfer
> 
> > -----Ursprüngliche Nachricht-----
> > Von: Doepfer_a100@yahoogroups.com
> > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von techmaster242
> > Gesendet: Sonntag, 27. Juli 2008 23:00
> > An: Doepfer_a100@yahoogroups.com
> > Betreff: [Doepfer_a100] DIY #1 humming?
> >
> >
> > I have an A-137 and A-110 in a DIY #1 kit, mounted in a wooden case.
> > For power, it uses a 120v->16v AC adaptor, that has two wires going
> > into the DIY #1's power supply, then it goes into the power bus.
> 
> How many mA output current has the adapter. It should have 2500mA to
obtain
> the same power as the PSUII (1250mA).
> At least twice the current sum of the installed modules is necessary
(e.g.
> sum of all module = 450 mA -> minimum current of the adapter = 900 mA)
> 

I believe it's 2500mA, and like I said, it's only powering two modules
so far.  It's a really nice power supply.  I still need to test the
whole thing in my own studio and with all the proper wiring, so I'm
not 100% sure that it has a hum.  It just did it at a friend's place,
which I admit isn't an ideal environment.  I'll know more in about a
week when all my cables come in, and post the results on here...