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DIY Stompboxes => Building your own stompbox => Topic started by: fatfoohy on October 06, 2010, 09:47:34 PM

Title: best capicitor for a flatline?
Post by: fatfoohy on October 06, 2010, 09:47:34 PM
So, question time.  The capacitor parallel to the LED from the led/ldr combo, what is the best value for it? i was thinking that maybe if you made it a smaller value, it would cause a quicker attack time. However i have no idea, has anybody played with this thought? I'd do it myself, but im putting it in a 1590A and the cap with a socket doesnt fit. Thanks in advance (https://dl.dropbox.com/u/9029377/flatline.jpg)
Title: Re: best capicitor for a flatline?
Post by: CynicalMan on October 07, 2010, 03:32:40 PM
The attack time is mostly set by the LED/LDR. Reducing the cap reduces attack by a little bit, but not much, and reducing it too much causes a growly distortion on decays when the compression is turned up. I used 47u in mine because that was the lowest I could go without the distortion.
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 07, 2010, 03:45:38 PM
hmmm alright thank you for the insight, im just gonna go with 1 uf and hope for the best
Title: Re: best capicitor for a flatline?
Post by: MartyMart on October 07, 2010, 04:23:01 PM
I used a very small 16v 100uf cap .... no problems in a 9v circuit.

MM
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 08, 2010, 09:39:07 AM
hmmm.....boxed it up, but there's some distortion, i think i may have a short somewhere, but could the capacitor be causing this? it's just a little distorted
Title: Re: best capicitor for a flatline?
Post by: CynicalMan on October 08, 2010, 03:40:38 PM
Try increasing the cap from 1uf to 47uf or 100uf. Like I said, I got distortion when the cap was lower than 47uf.
Title: Re: best capicitor for a flatline?
Post by: Slade on October 08, 2010, 03:45:58 PM
1uF is way too low for that cap. I use 100uF too. I'm gonna try a 47uF, though, CynicalMan :icon_smile:
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 08, 2010, 11:12:56 PM
hmmm, well i have a 1uf, 4.7uf, 10uf, 47 uf, and 100uf, so maybe i'll check out the 47 and 100 tomorrow, thanks for all of your help guys!
Title: Re: best capicitor for a flatline?
Post by: askwho69 on October 08, 2010, 11:20:51 PM
IS FLatline Comp quieter than CS-3? is this required for boosting distortion? thnaks
Title: Re: best capicitor for a flatline?
Post by: MartyMart on October 09, 2010, 06:05:35 AM
fatfoohy - Just checked mine and it has a 16v 47uf in that position, I remember having a bit of
distortion and "weirdness" when going lower than that.

askwho69 - Flatline is very quiet in operation and has a TON of output volume for some great boost also.

MM
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 09, 2010, 01:51:24 PM
hmmm, yeah well i'll definitely try out a 47 and 100, for the record.....i feel retarded for misspelling capacitor in the title of this post
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 09, 2010, 05:07:23 PM
wow......put in the 100uf, fired this thing up, sounds amazing! i added a switch to go between normal, a boss, and then the expansion mod, and it sounds amazing all around! it really makes my slap bass sound orgasmic(am i allowed to say that?) thanks for your help guys!
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 09, 2010, 11:24:01 PM
got it boxed and working! my second build ever, and first in a 1590a, I'll post pics monday, it's late, and tomorrow im out of town
Title: Re: best capicitor for a flatline?
Post by: askwho69 on October 11, 2010, 12:38:35 AM
WOW really! i want this :))) can someone share some PCB on this great compressor please really need a compressor as booster CS3 is very noisy its great but low output :(
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 11, 2010, 08:23:01 PM
sustain is a 100k linear pot, volume is a 100k logarithmic, the switch and be a two or three way, two way(on on) would be compression and expansion, 3 way (center off) would be compression boost and expansion. to omit the switch put a jumper between where the wire connects to the board for the switch's middle lug and the pad that connects to the IC's first pin(between the red and black wire's pads
(https://dl.dropbox.com/u/9029377/PnP.gif)
(https://dl.dropbox.com/u/9029377/render.gif)
Title: Re: best capicitor for a flatline?
Post by: askwho69 on October 11, 2010, 11:56:58 PM
Thanks A Lot  bro.. is this layout verified? :)
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 13, 2010, 03:37:24 PM
it was verified before i added the mods for a switch, and now i have verified it (i omitted D5 for what it's worth)
Title: Re: best capicitor for a flatline?
Post by: Hides-His-Eyes on October 13, 2010, 05:01:35 PM
Protection diode backwards? Or have I missed something in the reflection?

Looks to be shorting 9v to ground...?
Title: Re: best capicitor for a flatline?
Post by: fatfoohy on October 13, 2010, 09:11:26 PM
oh no idea, i didnt make this layout....
Title: Re: best capicitor for a flatline?
Post by: askwho69 on October 13, 2010, 10:13:33 PM
i found a thread a while ago and it was said that d5 is backwards.. we can omit it as you did  :icon_question:
Title: Re: best capicitor for a flatline?
Post by: John M on January 12, 2011, 04:54:51 PM
Can someone please confirm I am understanding this correctly? If I want a longer attack time, I should increase the value of C5. This is a great compressor!!!

Thank you

John
Title: Re: best capicitor for a flatline?
Post by: CynicalMan on January 13, 2011, 07:46:11 AM
Increasing c5 will increase attack and decay. I only played around with decreasing the attack, not increasing it, so I don't know how much of an effect it would have, but it's worth a try.
Title: Re: best capicitor for a flatline?
Post by: edvard on January 13, 2011, 08:13:53 AM
Seeing as this is uses a homebrew LDR, can anyone vouch for a certain LED?
Normal or ultra-bright?
Red, Green, Yellow or some other color?