Akai S950 Firmware Mod: SP-12 / SP-1200 GRIT on All 8 Voices

SP-12 aliasing on a stock Akai S950, on all 8 voices. SP MODE is a software update for the S950 sampler OS and boots from floppy or Gotek. No EPROM change, no soldering. Get the OS: https://tailout.de/os-mods Sample libraries, firmware and mastering: https://www.tailout.de Every S950 voice has a 36 dB/oct anti-alias lowpass (MF6-50, 6th-order switched capacitor), clocked by its own 8253 timer. Akai's OS lowers that clock whenever you play a sample below its original pitch, so the filter closes and the top end disappears. SP MODE switches the tracking off. Pitched-down samples keep their highs and alias the way an E-mu SP-12 (12-bit, 27.5 kHz) does. First, sine samples played 8-voice polyphonic show what the switch does: watch the alias peaks on the right side of the analyzer come and go. After that you hear a Rhodes and the Amen break on the S950 in SP MODE and on an E-mu SP-12. SP MODE sounds the same as my SP12 grit hardware mod, WITHOUT SOLDERING and on all 8 voices instead of voice 1. What's new in the sampler OS: SP MODE on the Master Tune page: filter tracking off on all 8 voices Switch it from the front panel or via MIDI CC 77, live while playing FILTER 0-99 covers the whole range, about 166 Hz to 20 kHz on a log curve (the stock OS does nothing below ~22 and above ~80) Finer filter steps with a 16-bit divider instead of 8-bit Filter clock never drops below 8 kHz, which keeps clock bleed out of the audio Boots from floppy or Gotek, no EPROM swap Note: because of the new filter curve, existing programs can sound different than on the stock OS. Back to stock: boot from the internal ROM. Chapters: 0:00 Intro 0:12 SP MODE OS: sine samples, 8 voices 0:27 SP MODE on/off on the Master Tune page 0:42 Rhodes: Akai S950 SP MODE 1:01 Rhodes: E-mu SP-12 1:25 Amen break: E-mu SP-12 1:52 Amen break: Akai S950 SP MODE 2:05 Loading the OS + changelog More from the workbench: SP12 grit hardware mod for the S950:    • Akai S950 SP12 Grit Mod - aliasing A/B vs....   E-mu Emulator II OS mod (EIIFX), live sample rate down to 243 Hz:    • E-mu Emulator II Firmware Mod: 1984 Sample...   All OS mods for vintage samplers: https://tailout.de/os-mods/ Prefer samples over soldering? My libraries come from the same kind of gear: vintage samplers and drum machines, many recorded through a Studer A820 tape machine. Akai S900 kicks, 12-bit from a modded S900: https://tailout.de/product/akai-s900-... Free taster pack: https://tailout.de/product/all-free-t... All libraries: https://tailout.de/product-category/s... Sampler OS mod by Jacob Korn at TAILOUT TAPEMASTERS 2026 - https://www.tailout.de I was product manager and in charge of quality management for MAGIX Sound Forge and the MAGIX audio plugins. Akai and S950 are trademarks of their respective owners, used only to describe compatibility. Not affiliated with or endorsed by Akai. Install at your own risk. #AkaiS950 #SP1200 #CustomFirmware #FirmwareMod #OSmod #NewFirmware #Lofi #SP12 #Sampler #VintageSampler #BoomBap #Aliasing