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DIY Stompboxes => Building your own stompbox => Topic started by: benl560 on March 08, 2011, 04:53:11 PM

Title: subbing components. what should i look for?
Post by: benl560 on March 08, 2011, 04:53:11 PM
specifically, diodes.

http://freestompboxes.org/members/soulsonic/schematic/LAL_SuperOscilloFuzz.GIF

what should i be looking for in a substitution for a 1n771a?  or any diode for that matter.
Title: Re: subbing components. what should i look for?
Post by: benl560 on March 08, 2011, 04:54:10 PM
and why, if someone would be so kind, does the fsb.org site always get censored?
Title: Re: subbing components. what should i look for?
Post by: Hides-His-Eyes on March 08, 2011, 05:23:33 PM
If you want to talk about stuff found on FSB, it's best to ask on FSB. The divorce wasn't pretty (and some would say that FSB got custody of the children  :icon_lol: )
Title: Re: subbing components. what should i look for?
Post by: CynicalMan on March 08, 2011, 06:21:48 PM
That image is blocked anyway. Is this what you're talking about?

(http://i1226.photobucket.com/albums/ee420/bail23/LAL_SuperOscilloFuzz.gif)

Prettu much any normal silicon diode can be subbed for the 1N4148. The same probably goes for the 1N4001 but you should probably get a second opinion on that. The 1n2771a diode doesn't even seem necessary to me. It looks like polarity protection for the LED, which should be able to handle itself.
Title: Re: subbing components. what should i look for?
Post by: benl560 on March 08, 2011, 06:54:05 PM
Quote from: Hides-His-Eyes on March 08, 2011, 05:23:33 PM
The divorce wasn't pretty
aaaahhhh... yeah, everyone hates a bad breakup. sorry

Quote from: CynicalMan on March 08, 2011, 06:21:48 PM
The 1n2771a diode doesn't even seem necessary to me.
thats the one. i couldnt really figure out what it was for.

ok, im still learning this, but:
the 1n4148's are clipping? and:
the 1n4001 is to block dc?

thanks a much
Title: Re: subbing components. what should i look for?
Post by: blueduck577 on March 08, 2011, 08:41:25 PM
The way the diode is reverse biased makes it look like a zener diode or something.  You'd probably be fine just leaving it out
Title: Re: subbing components. what should i look for?
Post by: CynicalMan on March 08, 2011, 09:27:53 PM
Quote from: benl560 on March 08, 2011, 06:54:05 PM
ok, im still learning this, but:
the 1n4148's are clipping? and:
the 1n4001 is to block dc?

The 1N4148s are for clipping. The 1N4001 is the polarity protection diode. If the power supply is the wrong polarity, the diode shorts the DC supply to ground.
Title: Re: subbing components. what should i look for?
Post by: Johan on March 09, 2011, 12:30:51 AM
the zener is there to let you know when battery voltage falls to low. when the battery falls towards the combined zener and LED forward voltage the LED dims. when the LED doesnt light up anymore, replace the battery.
...but as stated, for the function of the FX, you dont need it.
J
Title: Re: subbing components. what should i look for?
Post by: PRR on March 09, 2011, 02:13:40 AM
"1N771A" is a Ge diode, 100V breakdown, 200mA rating, 1V max drop at 100mA.

If wired as shown, the LED will get less than 25uA of diode leakage, and the glow will be invisible.

I suspect it is NOT a 1N771, but (as blueduck says) a low-voltage Zener for lo-batt hinting, and can be omitted (LED direct to +9V).
Title: Re: subbing components. what should i look for?
Post by: benl560 on March 09, 2011, 04:46:48 PM
ok, i see.
i wont even be installiing a battery snap, so ill be good there.
thanks much