Synthesizer
I picked up the pen again and sketched a familiar shape on the paper.
Since implementing all 88 keys like a real piano would take too much board space, I roughly drew just the 12-key layout for one octave.
“Luna, can you make a control device that looks like this drawing? So that pressing each panel adjusts the mana amount I mentioned earlier and sends it to the circuit.”
Luna narrowed her eyes at my explanation and flicked my forehead with her index finger.
“Lia, it's mana pressure, not mana. Keep mixing up terms and even I'll get confused~? Well, I get the gist perfectly, but later you're teaching me basic magic engineering from the ground up~.”
Yeah… future me, fighting.
Luna grumbled but scrutinized my drawing closely before quickly grasping the intent.
As expected of a grand mage—her insight was razor-sharp.
“So, you want these 12 panels to send progressively higher mana pressure to the circuit the farther right you go~?”
“Exactly. Can you do it?”
“Piece of cake~.”
Luna placed her hand on the board and swept lightly over it. In an instant, a precise input device circuit divided into 12 sections was engraved.
“There, next?”
“Now I need a part to control the volume—the overall sound loudness.”
“Simple~.”
Luna boldly began engraving the next circuit into the empty space on the board.
Like a master artisan embroidering, complex magic symbols settled in neatly.
But the real challenge started now.
“Next one's trickier. It's a circuit for controlling temporal sound changes… called an ADSR envelope.”
“A… what?”
Luna tilted her head at the unfamiliar term.
To help her understand, I explained the four stages step by step.
“When we play an instrument, the sound doesn't just pop and vanish, right? There's the attack time to reach max volume, the decay time dropping from peak to sustained level, the sustain volume held while pressing, and the release time until it fully fades after letting go. Tuning these four gives that instrument-like quality.”
Luna's eyes sparkled as she listened.
Introducing a time axis to finely knead mana flow.
Plenty to ignite a grand mage's scholarly fire.
“Hmm… so you're magically fixing dynamic changes over time? This is sneakily fun~? But Lia, the timings and volume levels—you'll adjust those yourself later, right?”
“Oh, yeah! As expected of Luna.”
“Hold on. This'll complicate the circuit…”
Luna grabbed another board and started engraving with far more focus.
Soon, the board glowed brightly as the circuit completed.
“First time thinking like this~? Okay, what's next? Spill it quick~.”
Luna buzzed like a kid, prodding for the next step.
Amazed at magic handling it all, I sensed completion nearing.
“Now engrave the magic that converts this waveform to actual sound. Oh, don't connect the circuits yet.”
“Conversion magic? Baby steps.”
Luna engraved it on the output side without pause.
All parts were ready now.
Okay, think… what was the signal flow structure again?
Staring at the boards, I carefully dredged up memories.
The synthesizer basics I'd memorized endlessly.
I traced the path in my head: signal from oscillator, through processing stages.
“Luna, time to connect. First, link the control device to the oscillator magic circuit.”
“Yeah~ keep going. Listening.”
No sooner said, Luna drew mana threads from her fingertips, bridging the boards.
True to a grand mage—no hesitation in tweaking engravings or linking.
“Route the oscillator's waveform output to the volume control circuit.”
“Next?”
“Connect the ADSR envelope to the volume control. Volume auto-adjusts to the envelope's output signal.”
With each instruction, intricate mana wiring sprawled across the boards in real time.
A past-life job for dozens of patch cables flowed organically from Luna's fingertips like a living thing.
“Ah! Luna, just hit me—make the envelope retrigger from start every time the control gets input.”
Nearly forgot retrig.
“Ehh~? Lia, warn me ahead! Was wrapping connections~.”
Luna puffed her cheeks, grumbling—but her fingers flew, revising at blinding speed.
Too gleeful for a complaint; I felt guilty.
“Done! Really the end now?”
“Yes! Last: connect volume control output to the physical sound conversion magic.”
The final mana strand stretched from Luna's fingertip to the output terminal.
The sine wave's vibration was primed to enter the world.
No filter yet—the heart of subtractive synthesis.
Filter later, via trial and error. Priority: confirm proper pitch output.
I swallowed, gazing at the final board Luna handed over.
Press any of those 12 panels, and sound would emerge.
If the design held…
Heart hammering like it'd burst from my chest—anticipation raw.
A sound heard thousands of times before, but magic-forged? Worlds apart.
Trembling fingertip to the leftmost panel—C.
Carefully pressed.
“Here goes.”
The instant I lightly tapped the first panel—
“Woooooong—!!!”
“Kyaaak?!”
A roar dwarfing expectations shook the mansion.
Luna had overjuiced the sound conversion output—a mere sine wave thundering like earth itself.
—Clatter, clang!
Teacups danced wildly on the living room table; wall ornaments plummeted.
“Whoa! Output's insane?!”
Luna whipped her hand—transparent barrier snapped up around us.
Direct shock dodged, but the majestic bass beyond battered eardrums relentless.
Ears plugged, I screamed.
“Luna! Volume! Crank it down! Everything's shattering!!!”
Pandemonium pure.
As Luna frantically dialed back mana on the output line, frantic footsteps thundered from upstairs.
“E-Earthquake?! Or forest spirits wrathful?!”
Edelrin—guitar practice in her room—barreled down, wielding it like a club.
Disheveled golden hair flying, she burst in—and locked eyes with me amid glowing boards, ears blocked in torment.
“...Huh?”
Her gaze dropped to the bizarre boards on the floor.
Luna twisted mana wiring hastily—mansion-crushing roar tapered to faint hum.
No wind, no water: smooth, alien timbre vibrating the air faintly—unheard in this world.
“Haa… haa… Nearly died.”
Vibration hell ceased; I collapsed, heaving ragged breaths.
First lifetime hearing: artificial timbre, grain alien to nature.
Edelrin, stunned, nearly fumbled her guitar, mumbling.
“Master… what was that sound? Thought the mansion'd launch!”
She orbited the board dazed; I rubbed ringing ears, slumping sofa-ward.
Deafened yet thrilled with achievement, I pointed to the faintly glowing boards.
Answered cool as ice.
“Ahh… this?”
Last vibration's echo lingering, I replied.
“This is called a ‘synthesizer’.”