Hi

if the suitcase has an old-style transformer (rectangular) it might make
sense to mount the spring not in a parallel direction to the frame. You
may have to try a satisfying position by testing. Also you should obey,
that not only the transformer will cause some hum. Also (neon or
halogene) lights, powercables or wallwarts outside the doepfer case may
induce the hum to the coils of the springreverb.

Florian

pfichoux wrote:

> I was disappointed by the strong A199 hum noise in my brand new Doepfer
> A100 suitcase.
>
>
> Perhaps I didn't care enough about Doepfer's home page warning :
>
> "The spring reverb system is connected to the A-199 module via 2 cables
> with RCA phono connectors. As the reverb system is very sensitive to
> magnetic fields it has to be placed in a big distance from the
> transformer of the A-100 power supply - privileged in the left upper
> corner of the A-100 frame. The reverb system is mounted with screws and
> nuts or double-faced self-adhesive tape. There has to be sufficient
> space for the reverb system (about 20 x 7 x 5 cm).
>
> For frames that include the A-199 we recommend the usage of the new
> power supply PSU2. PSU2 has much less magnetic radiation (because of the
> ring core transformer) that may cause hum noise in the A-199."
>
>
> Nevertheless, I began to find another position for the A199 reverb
> spring.
>
> Now it is mounted inside the suitcase, on the top/handle side of the
> suitcase, open side of the spring reverb unit upwards, with double-faced
> adhesive tape.
>
>
> Hum noise used to appear with a mix at 8 (9 o clock : almost dry
> effect), now I can work easily with a mix at 5:5 (12 o clock).
>
>
> Someday I'll try to build a full shield around the spring unit, but I'm
> already completely satisfied of my brand new A100 suitcase.
>
>
> Cheers,
>
> Pierre
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>

--
Florian Anwander |ConSol
Tel. +49(89)45841-133 |Consulting&Solutions Software GmbH
Fax +49(89)45841-111 |Franziskanerstr. 38, D-81669 München
email: florian.anwander@... | http://www.consol.de