Diamond Drive Reduced Gain

[DeadAirMD]

I'm still learning to read but more so understand schematics. Would there be a change I could make to this circuit, like lowering a resistor value to reduce gain? Would putting a resistor across lugs 1 & 3 of the Drive pot reduce gain or reduce the Drive pot's gain control level? Any and all help/education is welcomed and appreciated.

 

[BuddytheReow]

You could do 1 of 2 things from looking at the schematic. Either reduce C2 or R7. Reducing R7 will still give you the same amount of gain on tap, but you can dial it down more. C2 will reduce the overall gain. Or you could remove C2 altogether.

 

[DeadAirMD]

Thanks a bunch for the ideas Buddy. How did you come to that decision? What on the schematic made that jump out to you?

 

[BuddytheReow]

There are 4 circuit blocks here. Since you wanted GAIN tweaked, I looked for a gain control and it's in this first section. Looking at the drive control, all it's doing is throwing all signal to ground with a 100k resistor stopping it. Lowering that resistor's value will dump more signal to ground. C2 is a bypass capacitor and within limits, the higher the value the higher the gain of the transistor. You can try this on a breadboard with a BJT and wire it up like a LPB-1 with the added electro cap to see what I mean. The breadboarding part solidified the learning process for me.

 

[cdwillis]

I would increase reduce R7 to 10k and increase C6 to 10nf. That should lower the minimum gain, but also maintain the frequency response I think. If you left C6 at 1nf it would probably sound a little thinner at the minimum gain setting.

 

[DeadAirMD]

Thank you very much for the replies and circuit lesson. You made that very easy to understand and I definitely have a better grasp on what's going on and why. I'll for sure break out my breadboard gear this weekend and do some experiments.

I already modded C10/18 with two dpdt toggles with some different cap values and have been having a ton of fun tweaking the tone aspect of this circuit.

 

[KR Sound]

You can try this on a breadboard with a BJT and wire it up like a LPB-1 with the added electro cap to see what I mean. The breadboarding part solidified the learning process for me.

That’s a great idea

 

[mdc]

You could put C2 on a switch and have a lo/hi gain toggle.

 

[DeadAirMD]

Exactly what I was planning on doing. Great idea