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DIY Stompboxes => Building your own stompbox => Topic started by: Alpha579 on February 07, 2004, 06:09:54 PM

Title: MosFETs As Diodes
Post by: Alpha579 on February 07, 2004, 06:09:54 PM
Hey all,
How do u wire Mosfets/Fets as diodes. Do u guys think they sound good? I read sumwhere they sound more tubish?
Thanx for input,
Alpha
Title: MosFETs As Diodes
Post by: RDV on February 07, 2004, 06:21:39 PM
(http://www.diystompboxes.com/pedals/mosdiode.jpg)

Regards

RDV
Title: MosFETs As Diodes
Post by: Boofhead on February 07, 2004, 08:30:58 PM
MOSFET sound tubish when operated as *amplifers*.  When they are operated in reverse as a diode they are just a silicon diode, no real claim to tubiness - likes and dislikes are a personal preference here.
Title: MosFETs As Diodes
Post by: Peter Snowberg on February 08, 2004, 03:36:26 AM
In this case, Aron made use of the protection diode built into the power MOSFETs to get a new diode option. The actual transistor part is unused.

I do like overdriven JFETs and MOSFETs very much. They're more "tubey" than BJTs, but they're still not even close to real tubes. They're well worth exploring.

Take care,
-Peter
Title: MosFETs As Diodes
Post by: Transmogrifox on February 08, 2004, 03:08:10 PM
I have a distortion design using some 2N7000's as diodes that produces a very "Milkable" distortion.  Not exactly tube, but it's dynamic and responsive to picking and such.

I like the sound, it's very useable.  If you want, I'll scan in the schematic of the distortion I made and send you one...  transmogrifox@yahoo.com
Title: MosFETs As Diodes
Post by: Gringo on February 09, 2004, 10:03:16 AM
I'll mail you right away ;)
Title: MosFETs As Diodes
Post by: WGTP on February 09, 2004, 10:54:19 AM
I think they have a different sound, but I have blown up 2 2N7000's plugging them in and out of the circuit.  Be careful.
Title: MosFETs As Diodes
Post by: smoguzbenjamin on February 09, 2004, 11:20:16 AM
Blown up? :shock: As in BOOM and bits of plastic flying around or did you just let the blue smoke out? ;)
Title: MosFETs As Diodes
Post by: WGTP on February 09, 2004, 12:23:09 PM
I guess that is a little over dramatic.  Blown up as in things quite working and they no longer measure around .55 as a diode in the DMM.  Bad time of year.  Probably need to work on them in the Spring there is more humidity.  I have been using MPF102 jfet instead, they don't quite on me.  :shock:  :shock:  :shock:
Title: MosFETs As Diodes
Post by: Transmogrifox on February 10, 2004, 03:24:05 PM
You guys who emailed me for the distortion schematic, check your mail.

Be careful soldering MOSFETs as well, I have ruined a few by burning them too hot soldering the leads
Title: MosFETs As Diodes
Post by: Gringo on February 10, 2004, 03:44:41 PM
Are those coffe stains? Thats exactly the way my notes look after some tinkering  :lol:
Title: MosFETs As Diodes
Post by: Transmogrifox on February 11, 2004, 12:08:28 PM
Yeah, I think there's both coffee and beer stains on there. All my vices are accentuated while tinkering.  I must not be the only one, enjoy it to the fullest.
Title: MosFETs As Diodes
Post by: Transmogrifox on February 11, 2004, 12:15:06 PM
BTW Gringo, I love the pics on your page.  Your work bench set-up is not unlike mine, only my home-brew soldering iron stand is an old silver cup bought from a thrift store filled with coins.
Title: MosFETs As Diodes
Post by: Gringo on February 11, 2004, 01:30:44 PM
I tried many different stands after getting burned for the nth time :twisted:, the one in the picture is the last one, and seems to be taking it quite well.

I should have taken pics of my DIY amp's footswitch (added weight with 4 dead AA batteries), and my homebrew power source (boxed in a hand-assembled card board box)  :wink:
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