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No knob lead boost

Started by Gus, April 06, 2014, 02:55:11 PM

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Gus

C3 10uf note more mids but the curve still cross at about 80Hz (green input blue output)


The voltage 680K 120K voltage divider is driven by the emitter of Q1 this is coupled by C2. This is part of the bootstrapping

Q2 is a emitter follower
R8 C4 are a lowpass filter
Just looking at the first stage you should see the gain is LESS than 4.7 (47K/10K)and 9.4 (47K/.5K)you also need to work out the loading of Q1 collector for the true gain
C3, R6 sets when the gain goes up

Gus

18VDC humbucker adjusted lead boost sim idea.
R4 and R3 are bias adjusts for both stages the emitter follower is biased by Q1 collector
More bass increase C1

duck_arse

I breadboarded the "04/06/2014" tonight with 270pF input cap, and got hum along with hard and brite boost. voltages were close enuff, using bc549 and 549c.
granny at the G next satdy.

Gus

I simmed this with 2N2222s and the voltages were close.

Yes it was simmed as a bright boost.  I was thinking lead boost in a band setting at volume

For more bass increase C1 and less highs increase C4.  
More mids at less gain remove C3, R6
More mids at higher gain increase C3

Sims are posted as starting points add  remove frequencies(adjust the high and low pass filters) to what you want.

Thanks for the feedback