Re: DD20 odd behaviour: high-pitched constant whine in specific wiring situations

[andy butler <akbutler@tiscali.co.uk>]

Trying with a battery would be a diagnostic for checking
if the noise is introduced by the wall wart.

Boss style wall warts, with +VE earth can often
produce problems with noise.
Are you using one of those newer(smaller) switching mode warts?
Those can introduce a very strong signal onto the 
+VE earth line which would sound as you describe.

andy



Rainer Straschill wrote:

> My Boss DD20 has for a long time been integrated into a setup centered 
> around a Mackie 1202 VLZ Pro mixer (aka "Nerdville Setup"). After 
> remodelling that setup recently ("Nerdville 2.0"), I considered a 
> constant high-pitched shrieking sound emitting from the DD20.
>
> The sound is also present if there are no inputs connected to the DD20, 
> or if all other connections to the mixer are removed. The sound remains 
> if I connect the DD20 to different inputs of the mixer. Trying different 
> cables doesn't help, either.