Klein Bottle - Makeup Gain Trimpots

[benny_profane]

With my LP, I was getting a decent amount of distortion from the Klein Bottle itself. I adjusted the trimpots to mitigate this, but I had to go pretty low (~9 o'clock). The LP has humbuckers (so higher output), but that's no where near the signal amplitude of line level (which the KB can handle). This, of course, could because I'm running at 9V. I'm curious to know what experience other people have with the makeup gain trim.

[EBK]

I haven't touched my trimpots, but I play with vintage-spec single coil pickups, so I'm not much help.  Sorry.

[benny_profane]

I haven't touched my trimpots, but I play with vintage-spec single coil pickups, so I'm not much help.  Sorry.

No problem. Thanks for the response. I'm just curious more than anything.

Also, I think we've become the de facto Klein Bottle crew here.

[EBK]

Looks like we need to find some 10,000uF caps to mod our Klein bottles now.   !

[benny_profane]

Looks like we need to find some 10,000uF caps to mod our Klein bottles now.   !

Hahaha oh man that looks wild. Glad taking the board out isn't necessary. I never want to take it out of the enclosure.

[zgrav]

Not THAT'S a capacitor...

[benny_profane]

Not THAT'S a capacitor...

Bit wary of this one to be honest. Is this capacitance moving into danger territory?

[EBK]

Not THAT'S a capacitor...

Bit wary of this one to be honest. Is this capacitance moving into danger territory?

I'd have to refresh myself on the physics involved to guarantee your safety.

But...

If you keep your tongue away from that cap and make sure it is discharged before you solder it in, it cannot pose any sort of threat.

It would be storing a bunch of charge at a low voltage, much like a simple battery.


Another solution would be to cut the trace where those resistors create Vbias and add an op amp buffer daughter board.

I'm really mostly amazed that this giant cap is only $2.

[benny_profane]

Yeah, the voltage potential here is very low as well as current, but still should be safe about possible injury.

This cap is honking huge. I haven't placed a new mouser order yet but will get it when I do. Are you planning on both the cap addition and the resistor changes?

I kinda laughed at the video when he said that the other one wasn't nearly big enough. It's 680uF.

[EBK]

Yeah, the voltage potential here is very low as well as current, but still should be safe about possible injury.

This cap is honking huge. I haven't placed a new mouser order yet but will get it when I do. Are you planning on both the cap addition and the resistor changes?

I kinda laughed at the video when he said that the other one wasn't nearly big enough. It's 680uF.

Yeah, super huge caps can be a sign of less-than-optimal design.  Here, Peter really should have buffered that Vref if the other  parts of the circuit are pulling on that node as hard as they apparently are.

Still, I intend to perform all of the mods in the video as soon as I can justify a Mouser order.  No good reason not to do them all once you've started down that path, in my opinion. 

This build certainly seems like a rite of passage.