Differences

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--- rotordrive [2012/04/04 15:31] – created wadmin
+++ rotordrive [2019/12/24 23:24] (current) – wadmin
@@ Line 1: / Line 1: @@
 ==== RotorDrive ====
+{{ :rotordrive.jpg|}}
+RotorDrive is my first attempt at building a solid state DIY Guitar Overdrive. Design is based on a dual transistor gain stage for power overdriving.
+Design constraints were kept to the minimum : only components with nominal values (multiples of 10), only one gain control for the first stage.
+The distortion is asymetrical and provided by either transistor power saturation or the unique diode at transistor stage 2.
+When "DRIVE" switch is open, Rotordrive is in BOOST mode, providing a slight crunchy overdrive on single coil microphones, reasonalby maintaining the instrument timbre at the output.
+When "DRIVE" switch is closed, unit is in Overdrive mode, with highly distorted sound and weird harmonics.
+The sound of this medal is somehow quite "brute force". I recommend to combine it with a tone shaping network like the [[basic tone filter]] proposed here.
+The volume output pot is optional, recommended mainly for assembly in a case on a final product.
-Under Construction
 === Schematic ===
-{{ :schematic_v1.jpg?600 |}}
+{{ :schematic_v1.jpg |}}
+The "DRIVE" switch is SPT1.
+The "Gain" potentiometer is for ... Gain !
+The Gain can be modified by changing the feedback resistors R4 and R9
+Changing the transistors itself should result in higher gain (ex switching to BC550).
+Generally, this schematic can be easily extended on use. Consider having a good power supply regulation, according to the gain of this dual stage.
+Note : R13 should not be installed, it has been added for simulation purpose. The output of this pedal is the tip of the volume potentiometer.
 === Operation ===
+A few time diagrams from Tina are shown herebelow to illustrate both boost and overdrive modes.
+Both diagrams represent the effect of the Gain potentiometer from 0 to 100% when Rotordrive is fed by a 60mV peak input signal, close to a standard Mic.
 == Boost ==
-{{ :boost_60mv_input.jpg?600 |}}
+{{ :boost_60mv_input.jpg|}}
 == Drive ==
-{{ :drive_60mv_input.jpg?600 |}}
+{{ :drive_60mv_input.jpg |}}