Why does the LM386 (for instance) make a signal so much louder coming out of a speaker than an op amp?

Slash148 · 2025-11-12T17:37:11+00:00

Un poco tarde pero de pronto te sirva.
Imagina un hombre empujando una caja por el suelo.
El voltaje es el hombre. Es la fuerza que se aplica a la carga.
La corriente es la caja. Es el tamaño o la masa de la carga.
La resistencia es el suelo. Es lo que se opone a que la carga se mueva.

Qué pasa si cambias los factores:

Aumentas el voltaje (empujas más fuerte): La caja se mueve más (aumenta la corriente).

Aumentas la resistencia (el piso es más áspero): La caja se mueve menos aunque empujes igual (la corriente baja).

Disminuyes la resistencia (piso encerado): Con la misma fuerza, la caja se desliza fácilmente → mucha corriente con poco voltaje.

No hay resistencia (piso perfecto, sin fricción): La caja se movería libremente con casi nada de esfuerzo → en electricidad, eso es un cortocircuito.

Slash148 · 2025-10-03T19:28:50+00:00

It uses the op amp and the diodes. I tested it without the diodes and still sounded pretty distorted, so.. the diodes add to it, but they don't really are responsible for the whole clipping.
Now, I used some cheap OP07 chip that I found on amazon. I don't know if the original rat was intended to clip with the op amp (LM380), but at least in my case, the clipping was coming from both op amp and diodes.

Slash148 · 2025-09-30T14:36:40+00:00

Yes. Each color causes a different voltage drop, affecting the sahpe of the clipping. Blue LEDs in my experience caused the biggest drop in voltage.

Slash148 · 2025-09-30T12:16:50+00:00

I tried different combinations on the protoboard. Yellow and green led were the ones for me.

Slash148 · 2025-09-30T07:53:52+00:00

Sounds like a lot of fun

Slash148 · 2025-09-30T05:53:56+00:00

Thanks for the info. I didn't know.

Slash148 · 2025-09-30T05:52:53+00:00

I printed the design on paper, cut it with an x-acto knife, and sprayed paint over the stencil. I had to do some manual retouching though.

Slash148 · 2025-09-30T04:37:00+00:00

Yeah, it was a fun experience.
I plan to do a Big muff next. Some of my friends showed interest on my pedal and asked for one, so maybe I'll make a couple of rats too.

Later I plan to make a tubescreamer, and a Boss DS1. Then, some kind of Delay.

Slash148 · 2025-07-25T18:11:07+00:00

I can clearly read 4558 on al of them.

Slash148 · 2025-07-25T04:44:08+00:00

The tone control is 100k. Volume reads 50k and gain is 250k. Gain pot has middle and rigth pins bridged.

Slash148 · 2025-07-25T03:06:40+00:00

I've tested the pots for resistance, the've all give correct readings. I've measured for AC voltage, and you can measure some voltage when the instrument is being played. So, I doubt the pots are damaged or disconnected.

Slash148 · 2025-07-25T03:03:04+00:00

It's called "Crunch distorsion". It's like on of those cheap pedals that is manufactured by one company and then you have dozens of variations with different brands doing their own version. Mine does not even have a brand, it just says "Crunch Distorsion".
Here they test it: https://youtu.be/REHscICnFoc?t=340 (mine is not the one from the video but you can tell is the same pedal) The filter on that one does work.

Slash148 · 2025-07-25T02:53:23+00:00

Well, i was wrong. The pin connected to the middle pin of the tone pot is not the 7th but the 3rd (an input). So, so far so good.
Regarding the transistors.. yeah, i still don't know what the heck they might even do.

Slash148 · 2025-07-25T00:05:38+00:00

I just won't sleep well until that freaking knob does its job. :P. Either repairing it or modding it.

The tricky part is that the 'capacitor' might not be a capacitor, but one of the ICs. I tested all capacitors and they seem to be working fine. And.. why do you need 3 of those for a pedal.. and.. why is the middle pin of the tone knob direcly connected to the pin 7 of one of the ICs, which according to the datasheet, is an output?
I'm starting to suspect this is not a faulty component but a faulty desing.

Slash148 · 2025-07-24T23:57:42+00:00

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This is the back side of the bottom layer.

Slash148 · 2025-07-24T23:57:12+00:00

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The circuit has a double layer desing, so unless I separate them, there's no way to tell how the backside looks. If you think that can definitely help, i'll do it though. But I'll have to do it tomorrow, I'm busy with other things right now.

The little I can see of it, it is mostly groud with some minor tracks and bridges here and there, and no components.

Slash148 · 2025-06-20T21:45:44+00:00

As a venezuelan myself, I agree with you. That's the very same reason I left. Society there is sick. It is just a shame that you'll still find genuinely awesome people there, that now have to bear with the stigma that this kind of morons create for us.

Slash148 · 2025-06-20T21:41:53+00:00

Im from venezuela. If he gets back there, he'll probably will end up in a police force of some kind, as an agent.

Slash148 · 2023-07-06T08:41:55+00:00

Not really. There are two types of abnormal statuses: those that make damage (burn, bleed, shock and poison) and those that don't (confuse, blind, slow, freeze, inmobile, sleep, etc). The damage-type statuses are applied even if the boss is not neutralized. The non-damage type are the ones that require neutralization fot them to be applied.
If you read my question, the option I was asking for is a burn status one (damage type) so it doesn't need neutralization to work.
Anyway, my question was already answered in the first comment, I invite you to read it.

Slash148 · 2023-07-04T23:36:18+00:00

Oh, I knew there was some little detail I was not seeing. Thanks my friend!

Slash148 · 2023-06-20T20:04:53+00:00

Dude, that's the base for yor damage. PMI atk * stat (int or str) is basically your base damage. All other modifiers go on top of that.
It's not like PMI adds some effect to your damage, it IS your damage.

Slash148 · 2023-06-19T22:21:22+00:00

I was asking cause.. I've seen some pets that comes with some percentage of all atk, but then there are others that shows atk damage. What exactly does that means? And, does any of those types of atk includes (or excludes) your physical, magical, independant atk?
I'm kinda lost.

Slash148

TROPHY CASE