Author Topic: Klein Bottle - Makeup Gain Trimpots  (Read 285 times)

benny_profane

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Klein Bottle - Makeup Gain Trimpots
« on: July 25, 2019, 11:22:23 AM »
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 thatís no where near the signal amplitude of line level (which the KB can handle). This, of course, could because Iím running at 9V. Iím curious to know what experience other people have with the makeup gain trim.

EBK

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #1 on: July 26, 2019, 09:04:04 AM »
I haven't touched my trimpots, but I play with vintage-spec single coil pickups, so I'm not much help.  Sorry.
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benny_profane

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #2 on: July 26, 2019, 11:24:44 AM »
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. Iím just curious more than anything.

Also, I think weíve become the de facto Klein Bottle crew here.

EBK

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #3 on: August 11, 2019, 05:24:00 PM »
Looks like we need to find some 10,000uF caps to mod our Klein bottles now.   :o!

<a href="http://www.youtube.com/watch?v=Q-g2TZwPNhk" target="_blank">http://www.youtube.com/watch?v=Q-g2TZwPNhk</a>
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benny_profane

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #4 on: August 11, 2019, 08:24:53 PM »
Looks like we need to find some 10,000uF caps to mod our Klein bottles now.   :o!

<a href="http://www.youtube.com/watch?v=Q-g2TZwPNhk" target="_blank">http://www.youtube.com/watch?v=Q-g2TZwPNhk</a>

Hahaha oh man that looks wild. Glad taking the board out isnít necessary. I never want to take it out of the enclosure.

zgrav

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #5 on: August 14, 2019, 01:11:50 PM »
Not THAT'S a capacitor...

benny_profane

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #6 on: August 14, 2019, 01:18:03 PM »
Not THAT'S a capacitor...

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

EBK

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #7 on: August 14, 2019, 01:32:05 PM »
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.
« Last Edit: August 14, 2019, 01:41:22 PM by EBK »
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benny_profane

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #8 on: August 14, 2019, 01:56:45 PM »
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 havenít 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 wasnít nearly big enough. Itís 680uF.
« Last Edit: August 14, 2019, 01:58:18 PM by benny_profane »

EBK

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Re: Klein Bottle - Makeup Gain Trimpots
« Reply #9 on: August 14, 2019, 02:27:57 PM »
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 havenít 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 wasnít nearly big enough. Itís 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.
Not affiliated with Oatey, makers of the world's best and most delicious* low tar solder paste. Ask for Oatey -- It's the juiciest!

*Solder paste is not food.  If ingested, seek medical help promptly.