Soundskulptor EQ573 problems

[thomb]

Hi DIY Community,
i am new to the DIY community and  i hope to get help. Just finished the soundskulptor MP 573 and EQ573. The EQ is working but the Bell-Filter acts the most of the time as shelf-filter.  Randomly it works as it should (Bell character and the adjusted frequencies are shown at the analyzer).
Switching the center frequencies of the Filter i can see the frequencies in the analyzer jump up an down (as shelf) exept between the following frequencies : 500 and 700 Hz, 1.1k and 1.6k, 2.3k and 3.2k.
The other Filters work fine.
I taped the PCB and components to look for bad solderings or components. But i couldn´t make it work right by a specific tap, switch, adjustment.
Maybe somone could help.
Thanks a lot.
Kind Regards
Thomb

 

[Golgoth]

Did you contact Jean-Pierre @ Soundskulptor?
He will help you for sure!

 

[thomb]

Hi Golghoth,
thanks for the answer.
I am in contact with Jean-Pierre.
Before i send the unit back to Soundskulptor i wanted ask people in the forum.

 

[Golgoth]

Too bad you have to send it back!
I am not exactly an electronics scientist but if your problem happens randomly I think it could be a short or something a bit loose somewhere. What did Jean-Pierre tell you?
Also try contacting Udo, he's a scientist!  ;D >>> http://groupdiy.com/index.php?action=profile;u=40447

Could you also post some pictures?

 

[thomb]

I am in contact with Jean-Pierre and he helped me. His thinks it´s a dry soldering. But i can´t find it. I don´t know wich part of the PCB to search at first.
Two times when i tested the EQ and had a lamp over the EQ it worked right. Maybe the warmth of the lamp closed open connections.
What pics do you want? PCB from above?
@Golgoth: Do you have any Soundskulptor Units? I am very satisfied with the MP573.
I can´t compare it to any Neve Preamp but i like it. Also the EQ. It´s my first analog EQ. How does it sound compared to the other 1073 Eq´s out there?
Thanks.

 

[Golgoth]

A dry solder seems tangible. If you want to be sure reflow everything and add a little bit of solder where it seems to be needing some.
I built a few 501's PSU boxes from Soundskulptor but no modules yet so I don't know the sound.

 

[thomb]

Problem solved! It was a defect L1 (inductor). It was a term on guarantee. Jean-Pierre fixed it for me.
Yeahh