madbeanpedals::forum

Projects => General Questions => Topic started by: teknoman2 on July 09, 2014, 08:29:33 AM

Title: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 09, 2014, 08:29:33 AM
This month I am thinking of design a delay with 550ms using 4 mn3008,
all four BBD chips will be on the pcb from the start.
The idea is not to use any daughter boards and not any modulation.
Probably it would be like cloning the m@xon AD 900.
So here is my schematic of the BBD.
I don't believe there is a mistake somewhere but it is always good to check another pair of eyes.

For a misterious reason I don't like daughter boards,
I don't know why, despite that they will make my pcb design easier and could give me the oportunity to change the BBD chips from mn3008 to mn3005.

Any recommendations or changes are welcome.
Title: Re: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 09, 2014, 01:39:11 PM
I believe the jpeg is a bit hard to read it cause its too big.
Without any details I just add two mn3008 between ic3 and ic4 (existing BBD chips on the Aquaboy DX project).
In other words its a Aquaboy Dx removing modulation and adding two BBD chips to finally achieve 550ms.


Title: Re: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 10, 2014, 08:19:52 AM
Quote from: teknoman2 on July 09, 2014, 08:29:33 AM
Any recommendations or changes are welcome.

Do you think its ok to make a prototype with this schematic?
My only concern is the callibration which I believe is the same as the Aquaboy.
Callibrate first BDD then second, third, forth with BIAS trimms and last converging the waveforms via Cancel switch.
Do you think will I face any issues, or should I change anything on the schematic?

Title: Re: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 11, 2014, 10:32:24 AM
Bump :(
Title: Re: 4 x mn3008 550ms Delay
Post by: culturejam on July 12, 2014, 06:41:24 PM
Probably nobody is responding because we can't see the whole schematic. I'm not going to render an opinion on whether or not a whole circuit might work if I can only see half of it.
Title: Re: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 12, 2014, 07:23:48 PM
My bad, sorry for that.
I didn't upload the entire schematic cause basically its like the aquaboy dlx without the modulation
and my main concern is about the BBD stages.

Here is my final schematic.
Hope this helps.

*edited : pin2 of T1 connected with 220n cap.
Title: Re: 4 x mn3008 550ms Delay
Post by: ThePastRecedes on July 12, 2014, 10:06:09 PM
T1 doesn't seem to do anything... I can't give any help with the BBD part though... I've just started reading about them.
Title: Re: 4 x mn3008 550ms Delay
Post by: teknoman2 on July 12, 2014, 10:35:17 PM
Changed the T1 connection,

thanx mate.