Author Topic: yet another stupid newb question  (Read 1586 times)

lightningfingers

yet another stupid newb question
« on: March 09, 2004, 04:41:17 PM »
mmkay  im building an phase 45 (from the tonepad site)
where in gods name do i get those FETs from
U N D E F I N E D

RDV

yet another stupid newb question
« Reply #1 on: March 09, 2004, 04:57:27 PM »
http://www.smallbearelec.com
Hit the stock button.

Regards

RDV

petemoore

Mine fired up
« Reply #2 on: March 09, 2004, 05:17:21 PM »
With plain old MPF102's from RS..
Convention creates following, following creates convention.

Chris R

yet another stupid newb question
« Reply #3 on: March 09, 2004, 07:01:12 PM »
From the DIY FAQ link above

"The NTE458 usually has more gain than the J201, and the 2N3686 can provide gain of 500. The 2N5457, MPF102, and 2N3819 will produce less gain. Other substitute transistors include 2N5484, 2SK43, 2SK68, 2SK117, 2SK118, 2SK121, 2SK163 and BF245."

Mark Hammer

yet another stupid newb question
« Reply #4 on: March 10, 2004, 09:51:40 AM »
The FETs are not chosen for their gain in this instance, but for their ability to produce a reasonable (and equivalent) rate of resistance change for the range of LFO voltages that will be driving them.  What makes a J201 great for a distrtion unit does not necessarily provide ideal characteristics for a phaser or compressor or gate.

Other FETs besides the 2N5952 *will* work (K30A, BF245, MPF102 are frequently observed as control elements in phasers) but the 2N5952 just happens to fall in the sweet spot and makes selection/matching a whole lot easier and more troublefree.  There is a nice document at RG Keen's www.geofex.com site on matching and identifying FETs suitable for phaser use.