Saturday, September 18, 2010

Guitar Peamp: Buffer + Booster (easy to read schematic)

This is the schematic that I wrote about in the post: New guitar preamp project
It shows a construction of a guitar preamp with some untypical switching system and clear, warm tone.
I made it for those of you, who want some more clear and easy plan.

List of parts (the same like in previous post about this preamp):

1. op-amp: NE5532
2. potentiometer: logarithmic, 100 – 200 kOhm recommended (any value will work to some degree)
3. switches:
     2x DPDT on-on
     SPST on-off (power switch) 
4. electrolytic capacitors:
     C1, C3, C5: 10 uF
5. film capacitors:
     C2: 0,1 uF
     C4: 600 pF (0,0006uF)
6: resistors:
     R1, R2: 100 kOhm
     R3: 1 Mohm
     R4: 1 kOhm
    R5: 10 kOhm (gain 11x), or 20 kOhm (21x), or higher value, up to 40 kOhm – You can try to use even some higher values than 40 kOhm for more gain and really big crunch, but it can make some unwanted distortion effect.
Personally, I like to using boosters only for a little "warm-up" or a little bit of crunch tone, so 10 kOhm is enough for me.
     R6: 250 Ohm

All grounding points should be connected together in one place.