Doepfer

I've seen a few posts about this but haven't seen anybody mention any confirmed resolution.

i've got a mean hum in my system when using this kit. 

these are the north american power supplies I'm using:

input:120vac 60hz 15w
output:12vdc 500ma

are these good?

thanks for any help.

~j

> I've seen a few posts about this but haven't seen anybody mention
> any confirmed resolution.
>
> i've got a mean hum in my system when using this kit.
>
> these are the north american power supplies I'm using:
>
> input:120vac 60hz 15w
> output:12vdc 500ma
>
> are these good?
>
> thanks for any help.
>
> ~j

It's essential that the two power supplies have regulated 12V outputs.
Unregulated output will cause hum in any case !
The A-100DIY#2 does nothing but use the two supplies for +12V and -12V
directly (no additional electronics. The small pc board of the A-100DIY#2
only distributes the two voltages to the bus boards without any additional
stabilization or filtering. That's why the info page of the A-100DIY#2 says:

"This is an extremely inexpensive version of the power supply. The quality
cannot be compared to those of the normal A-100 power supply (A-100PSU2).
Stability of the voltages is significantly worse compared to the regular
A-100 power supply (A-100PUS2). Especially if VCOs are are used tuning
problems may occur ... In case of doubt we recommend the A-100 DIY Kit 1  as
the voltage stability of this kit is much better."

Best wishes
Dieter Doepfer

I have to assume that I received the proper supplies from the north american distributor.

yeah it looks like I'll save up for another power supply. it's true I was warned, it seems as 
though the last person who posted on this issue wound up selling their unit.

I'm not sure why this isn't working for me.. oh well.


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

>
> > I've seen a few posts about this but haven't seen anybody mention
> > any confirmed resolution.
> >
> > i've got a mean hum in my system when using this kit.
> >
> > these are the north american power supplies I'm using:
> >
> > input:120vac 60hz 15w
> > output:12vdc 500ma
> >
> > are these good?
> >
> > thanks for any help.
> >
> > ~j
> 
> It's essential that the two power supplies have regulated 12V outputs.
> Unregulated output will cause hum in any case !
> The A-100DIY#2 does nothing but use the two supplies for +12V and -12V
> directly (no additional electronics. The small pc board of the A-100DIY#2
> only distributes the two voltages to the bus boards without any additional
> stabilization or filtering. That's why the info page of the A-100DIY#2 says:
> 
> "This is an extremely inexpensive version of the power supply. The quality
> cannot be compared to those of the normal A-100 power supply (A-100PSU2).
> Stability of the voltages is significantly worse compared to the regular
> A-100 power supply (A-100PUS2). Especially if VCOs are are used tuning
> problems may occur ... In case of doubt we recommend the A-100 DIY Kit 1  as
> the voltage stability of this kit is much better."
> 
> Best wishes
> Dieter Doepfer
>