In his latest video, RobSmithDev returns to a decades-old project: rebuilding the CU Amiga Sound Sampler. The device first appeared in CU Amiga magazine’s May 1993 issue, promising readers a low-cost way to record audio on their Amiga. Back then, audio capture required expensive external hardware like the Techno Sound Turbo. Rob tried building the DIY version, but his sampler never worked. Thirty years later, he’s determined to solve the mystery.
To recreate the CU Amiga Sound Sampler, Rob locates the original ZN448E analog-to-digital converter chip and designs a modern PCB version of the old stripboard layout. He explains each step in detail, showing how analog-to-digital conversion works and why older chips had strict frequency limits. His updated design looks clean and professional, thanks to modern PCB fabrication and assembly services.
Once built, he tests the circuit on his Amiga. However, it fails to record any sound—just like before. Rob then investigates deeper, comparing the circuit against CU Amiga’s June 1993 issue. There, he uncovers a vital correction: the capacitor marked “7μF” in the original design was a typo. The fix calls for a 47μF component. After replacing it, the sampler performs slightly better but still produces no clear sound.
Next, Rob examines the chip’s timing circuit. He discovers the clock capacitor value is far too high, slowing the chip to 287 Hz instead of 30 kHz. By swapping it with a 4.7 nF capacitor, the circuit suddenly behaves correctly. The result is a working CU Amiga Sound Sampler after three decades of trial and error.
The moment it plays sound is both satisfying and nostalgic. The audio quality isn’t perfect, but it’s proof that persistence pays off. Rob closes the video by inviting viewers to share their experiences and hints at a future episode exploring commercial Amiga samplers.
This video is a must-watch for retro enthusiasts who love seeing vintage hardware brought back to life.
