This Week on the Breadboard: The Celestial Boost

[Chuck D. Bones]

Nice work, James, see what you're started?

There needs to be a WTF icon in the LIKE menu. I know I'd use it.

I remember when we used to talk about pedals...

 

[HamishR]

In Australia we call it shit-stirring. I have been called a shit-stirrer many times. It is considered a noble art here by the cognoscenti. Some of our most famous exports have been shit-stirrers. And New Zealand has some of the finest. The Kiwi sense of humour can be amongst the world's driest.

You said something about pedals?

 

[szukalski]

Back on topic, the faceplate came with lessons learned about playing with different layers, but it’ll work:

 

[Nic]

Back on topic, the faceplate came with lessons learned about playing with different layers, but it’ll work:
View attachment 58301

Fuzz, Boost or ...... w"h"ine ? Volume and Bass are not that bad, I quite like the effect if I must say.

 

[Chuck D. Bones]

Looks like white wine to me.

 

[zgrav]

Back on topic, the faceplate came with lessons learned about playing with different layers, but it’ll work:
View attachment 58301

Almost looks like a "Pass" control. A bit more detail in the stem for the wineglass and it could be a P*ss control (your choice of vowels)

 

[HamishR]

Yeah I'm getting notes of flux, fibreglass and lanolin...

 

[MichaelW]

Demo posted here.

 

[Chuck D. Bones]

Lookin' good!

 

[MichaelW]

Lookin' good!

Great circuit Dave!

 

[MattG]

@Chuck D. Bones - I want to build the boost-only circuit. Is the first schematic you posted still considered good for that? Or is the tweaked more complex circuit in boost mode better than the boost-only circuit?

And if that first boost only circuit is still viable, should Q1's drain be set for 5.4v as in the latter circuit?

Thanks!

 

[Chuck D. Bones]

@Chuck D. Bones - I want to build the boost-only circuit. Is the first schematic you posted still considered good for that? Or is the tweaked more complex circuit in boost mode better than the boost-only circuit?

If all you want is clean boost, then the circuit in post #1 will get you there. At higher GAIN settings, less bass gets thru Q1. You can compensate for that by adjusting the BASS knob. The way I would set the knobs is start with BASS & TREBLE at 5, VOLUME at 10 and adjust GAIN for the desired boost. Then adjust the EQ.

And if that first boost only circuit is still viable, should Q1's drain be set for 5.4v as in the latter circuit?

Select Q1 to get close to 5.4V when GAIN is dimed, then fine-tune by adjusting R6. Try to keep R6 between 35K and 45K for best results. Note that the GAIN knob affects the bias and might scratch when turned.

If you don't need the clipping option, then omit S2, D1, D2 & C15. For maximum headroom, omit D3 & D4. If you take all four (D1-D4) out, then you can omit R7 and jumper C3.