Howdy folks. Yesterday I got a "commission" to build an SHO for a friend (OK, so its being traded for a case of beer and a bit of auto repair) and while sourcing parts I ran into an interesting conundrum.
Just about every layout for the SHO I can find lists the fet as a BS170.
BUT! In the instructions that come with the pedal itself, the part is listed as a BS107 ( https://static1.squarespace.com/static/555e332ce4b0577e788c3a16/t/559efbf3e4b0ea46bca0bfec/1436482547498/ZVEX+Super+Hard+On+Instructions.pdf )
Both small signal mosfets, but with somewhat different parameters. So, who is being dyslexic here. Is the part listed incorrectlyin the zevx paper, or was the original gut trace misread? I can't find any clear pictures of the circuit in the pedal itself annoyingly, so I am curious if anyone here knows for certain.
https://www.onsemi.com/pub/Collateral/BS107-D.PDF vs https://www.onsemi.com/pub/Collateral/BS170-D.PDF
I've always used bs170, built many of them, sounds right to my ears.
I've used the BS170 & the 2N7000 and hear no difference. The footprint is a 180 degree turn.
(http://i216.photobucket.com/albums/cc305/davent/IMG_2635.jpg)
dave