AD3208 delay time problem :s

[ThomasDJ]

Hi,

I've just finished the AD3208...and everything seems to work fine except from the 1M trim and 500K pot! The delay time is tooooo fast...even if I turn the 1M trim at max..

I am a beginner :s ...can anyone please help me??

Regards Thomas

[redeffect]

Hello and welcome. I have a funny feeling you are expecting more from this unit than it can deliver. 2XMN3208=4096 stage delay line. The same as your "garden variety" commercial analog delays. (allegedly 300ms. although the math would beg to differ...) Re-read the article about this unit on GGG. You might want to swap one or both chips for MN3205s. This will give you 1.5 or 2X  the delay presently available to you. Do you have an analog delay you can compare it to? How fast is too fast? A bit more info would be helpful in diagnosing this issue. BTW; you really picked a whopper of a project for a beginner. Congrats on making it work! Sounds like it might just be a minor issue(if any...) In the mean time; try to compare it to a DM2, DM3, AD80, FX90, etc., and see what the difference in delay time is. Good luck, and let us know of your findings.
all d best
red

[ThomasDJ]

hello

Thank for your reply..!

Well I don't have an analog delay to compare whit but I am sure that the delay time is too fast. If i turn the 1M trim pot at max and the 500K pot at half the delay time is very fast...and at max there is no "delay" at all. I consider this as a fail thus the 1M trim pot is unnecessary..
I think the slowest delay time I get is about a half sec.

regards Thomas

[redeffect]

If the slowest delay time is "about 1/2 sec." as you stated; then you have a working analog delay. I have all the above mentioned delays; and can assure you none of them come close to that. 4096 stages driven by a 10K clock= ~200 ms. This is not a heckuva lot of delay. For me the beauty of analog delays is not so much the delay time; but the sonic quality. If you want more delay (just how much delay is enough?) check out the PT80 ( GGG ) and the SHEcho ( GGG). Also this thought... If you have the trimpot at max (1M) there must be some significant feedthrough (high pitched whine). Sounds to me like the only thing amiss is your expectations might have been a bit too high(welcome to the club ) Kick back; plug in; and play. Feel the textural quality, and enjoy it for what it is .
Happy building/playing!
red

[trevize]

Hi Thomas where did you buy your IC? I've read that there are chinese that salvage delay ic fromkaraoke and relabel them...
so you end up thinking you have a 4096 stage bbd instead of a 1024 one...

http://www.getlofi.com/2006/05/alert-bbd-delay-and-other-ic-scams.html

[ThomasDJ]

Hi red,

Well guess you're right ...maybe my expectations has been too high

Anyway I've got a nice delay...an actualy i like the high tone whines...except when they won't stop ...

Best regards Thomas

Hi treviz,

I've bought them at an Australian company.. www.futurlec.com