Simulation of the Boss MD-2 Mega Distortion Complementary Common Emitter Stage (Falstad)

Рет қаралды 3,746

Күн бұрын

Пікірлер: 32

@peddlereffects 7 ай бұрын

My nephew had a MD-2 early on and it struck me as “fine” - it was much more early-2000s nu metal than I cared for, but I also didn’t spend much time trying to dial it in. My impression was that it was more intended to give a bedroom player the vibe of recorded guitars vs the kind of pedal you might actually use if you were playing live & loud with a group. If I’m remembering correctly from 10 years ago, a lot more bass than I would want on my guitar tone.

@CraigStuntz 7 ай бұрын

In Falstad you can add an audio input (which requires going through a resistor and will need you to select an MP3 file) and an audio output and then listen to your distorted signal. :)

@blenderbuch 6 ай бұрын

I always wanted to try that audio input! Now I have a simulation which I can use.

@crock2434 7 ай бұрын

Long time musician and electronics hobbyist...thank you for your circuit and pedal videos....so far ive modded an orange amplifier preamp. Emg Active guitar circuit. And built a green ringer pedal with silent switching and a blend control. Thank you for being consistent with your content and inspirational to all...

@Lantertronics 7 ай бұрын

Thank you for your kind words!

@timescobedo3512 7 ай бұрын

Interesting how symmetrical the output simulates. It occurs to me that a simplified DC path can start to look like a BJT version of a CMOS inverter. It looks like they're running two parallel circuits, but share the biasing, which may be the particular novelty here. Otherwise, there might be no reason to do NPN/PNP transistors.

@elmegil 7 ай бұрын

That complementary end pair kind of reminds me of how the CGS lockhart distortion is laid out?

@wreckoningday 7 ай бұрын

Thanks for this video. I learned some valuable things from this. I know that discrete op amp is used in the blues driver, where else is it used?

@LearTrough 7 ай бұрын

Thanks professor for including the SPICE file of the circuit network. Since this thing is audio-related, is there a way by which the output of the FALSTAD simulator could be exported as an array of discrete numbers corresponding to the voltages at some appropriate sample rate so that I may use MATLAB to check how it sounds? That would be the best way to find out about its performance.

@AnalogDude_ 7 ай бұрын

it has audio out.

@LearTrough 7 ай бұрын

@@AnalogDude_ Oh, really? That's fine, but I cannot find the option. Can you give me the steps?

@AnalogDude_ 7 ай бұрын

@@LearTrough right click, "Outputs and labels" ---> Add audio output, add data output. Also the "Add labelled node", simplifies schematic by using "labels" instead of wires all over the place and less strain on the computer drawing currents or gives lines colors, like green and red.

@LearTrough 7 ай бұрын

@@AnalogDude_ Thanks a lot!

@samuelwynn737 7 ай бұрын

I have a question if that’s okay; so I wanted to make a pedal my self that’s a multi FX type. But I don’t know much about actual pedals and so I wanted to make it maybe with a razzberry pi or somthing like that, the simulation you made could it be used for that type of stuff and if so how can you make these simulations?

@Lantertronics 7 ай бұрын

Running a full-fledged circuit simulator like this is not practical for real time effects. Search on google for the electrosmash Raspberry Pi Zero guitar pedal project to get ideas (although it's pretty lo-fi). Also google for pi-fx. Also, I highly recommend checking out the Daisy Seed, it's a STM32 platform. Look up the PedalPCB Terrarium, which is a guitar pedal thingy you can plug a Daisy Seed into. And if you want to learn DSP programming, actually a good place to start is writing plugins for a DAW using something like JUCE, or even Cherry Audio's Voltage Modular (which you can get started with for free). You have much research ahead of you.

@CraigHollabaugh 7 ай бұрын

Are those input jfets in a single package?

@Lantertronics 7 ай бұрын

Nope, two separate discrete. No idea how much work Roland puts into matching them, if any…

@CraigHollabaugh 7 ай бұрын

@@Lantertronics probably no effort, mismatch will lead to distortion which is fine.

@JonDeth 7 ай бұрын

I suspect your summarization is accurate and it's intended to simulate valve distortion. When you overdrive transistors very deeply, it can sound more valve than a valve, so this quasi-complimentary pair provides a transistor to clip each half cycle so it has a good valve sound and a single transistor isn't providing the clipping for both half cycles. I suspect you're also correct and it's more asymmetrical than the sim is showing, but odd order harmonics do have more sleaze, raunch and decadence than even and the goal of the pedal is to produce metal distortion. When I hear pinch harmonics out of low, dominating even order harmonics, there's no raunch, sleaze and soul, just valve-like buzzing that reminds you of a synth and triangle waves. I would guess that this setup is also to prevent the dominant, high even order harmonics of semiconductors and a good blend of low even and odd order harmonics. Boss has the all-around market dominance of analog and digital gear in contrast to other brands' success in both. We've only just entered into digital being a 90% match to tubes, it started about 10-12 years ago, and has only just been in the last 3 to 4 where every brand caught up. I think that's a result of chip engineers being more mindful to provide circuits within the digital microcontroller to be able to produce asymmetrical and dominant low even order harmonics. Likely a product of everyone inspecting one another's solid-state analog and valve products for decades.

@johannalvarsson9299 7 ай бұрын

yes I own a MD-2 since 2002 and play it. Any questions?

@Lantertronics 7 ай бұрын

What do you think about the sound? How do you like to set your controls?

@johannalvarsson9299 7 ай бұрын

@@Lantertronics It actually has a quite "organic" distortion-texture, but on the flipside its a bit mushy and lose in the low-end. I mostly have all knobs at noon - not a very sexy answer I know. Sadly I dont have a ds-1 or 2 to compare it to, but I do use mt-2 and hm-2 clones. These sound a lot more aggressive and tight, though a bit more synthetic. For some reason, the noise floor of the md-2 is a bit higher than that of the two others. Lastly I might add that it doesnt seem to take boosts as well as my other pedals, so its not as easy to tighten it up. Its a decent pedal, I just dont get the "mega", because the mt-2 has way more distortion to offer.

@andrascreams 3 ай бұрын

at first i thought that big companies like boss use discrete components because they're cheaper. i've also checked thru schematics from ibanez, fulltone, MXR, etc and they all use IC op amps though. even some boss pedals do. my personal conclusion is that they may have started as a cost-cutting measure, but later were integrated into the sound of boss pedals. OR vice versa! these very primitive op amps create tons of distortion, have a lot of other finicky electrical characteristics, and boss wouldn't be using them unless someone decided they liked the sound they made.