Akai S900 Midi Digital Sampler (1986)

 

Rackmount sampler of the eighties, still widely used for oldschool sonic character

RACKMOUNT Main S900 panel features a 40 x 2 backlit display, 29 buttons, 3 knobs and a data rotary encoder.

Front panel terminal connectors:
- Mic / line inputs
- pedal trigger play

Back panel terminal connectors:
- 8 individual outputs
- stereo main out
- Midi interface
- custom voice connector to link Akai-compliant synths like VX or AX series
Note: old 2-progs power cable, you can still mod it to standard one.

SAMPLING core based on a 8-bits CPU NEC manages 8 voices polyphony.
The monophonic sampling engine works at 12 bits resolution and relative DAC is a BA9221 with various recording frequencies modes:

- from 7,5 kHz for 63 sec. max. - to 40 kHz for 11.75 sec. max.

EDIT A sample can be stretched up to a maximum of 6 octaves with famous high-quality Akai interval algorithms; special Warp pitch allows to time-stretch a section. Than a single (or more) sample has to be be placed in a keygroup and once mapped, finally, this makes a program.
Each Keygroup features individual parameters such as:

- Midi channel - zone assignment - EG amplitude - LFO amplitude - VCF cutoff - volume gain - velocity switch

-

SAMPLE IMPORT it is possible to sample dump handshake over Midi which is NOT compliant to standard SDS protocol and requires special dedicated softwares.

It is also possible also to use the RS-232C parallel port with old communication soft, but I do not have much information about this protocol, but a dedicated software is dedicated for this task.

 

FILTER non-resonant filter based on a MF6CN-50 a switched capacitor VCF a kind of an hybrid analog-digital offers -12dB/ Oct. slope. The VCF section also features a simple key filter function for keyboard note tracking on octaves.

LEFT- S900 filter MF - Click to enlarge picture -

 

LFO a single delayed triangle modulator vibrato with special "desync" option emulates natural acoustic vibration feeling. TIP: the LFO is triggered by modulation wheel or assigned to aftertouch.

ENVELOPE based on VCA BA6110 a 4-segments EG amplitude for each sample in keygroup + 1 EG overall amplitude bias for keygroup. The special positional crossfade tracks the amplitude up to +50% toward lower or higher octave. TECH: a second EG for filer is available when using OS 4.0.

STORAGE floppy disk drive format 3"5 DD 720 Kb capacity controller upd7265c.
The disk volumes are formatted at 800 Kb in Akai proprietary file system, thus the file system is not directly MS-DOS compatible, however ome third-party programs handle AKAI file system from PC computers.

Today it is possible to replace standard drive with a third part USB floppy emulator like HxC.

OS most common is 1.2 version burnt into EPROM chip which is able to boots higher 4.0 with floppy disk. The lastest OS4 adds more extra features like s900 timestretch, crossfade and a second EG for filter.

OS4 LATEST *IMPORTANT* the EPROM OS 1.0 does NOT have boot option so new EPROMS are required to access 4.0 by disk. *DOWNLOAD* S900 OS4 BOOTDISK TELEDISK IMAGE*

MAINTENANCE / MODS the inverter NEL-D32-43 power supply gets faulty and creates troubles with backlight; for replacement you can adapt a standard cheap display so do NOT get ripped by guys on Ebay: S900 / S950 displays replacement are STANDARD and cheap.

LEFT- old display just dimes out and dies. TECH: Also check out capacitors, bad soldering and click pops, take a look to this nice video tutorial about BAD RAM issues.

 

MEMORY:

- 750 Kb sampling RAM (cannot be expanded) - 32 samples - 32 programs - 16 keygroups. LEFT- AKAI S900 MOBO - click to magnify picture -

EDITOR just some old programs around:

- Soundfiler ST S900 by drumware (ATARI ST) PIC - Akaisex converts between 12 and 16 bits akai samplers format (ATARI ST) - Akai ZEROX (ATARI ST)

 

EXPANSION BOARDS:

	Ib 101a interface for Atari hard disk - special ASCSI (not SCSI standard! ) Atari volume hard disk.
	Marion Ms9c - upgrade board to 16 bits resolution.
	ASK-90 external trigger board- triggers 8 voices from external signal. ASK-90 TRIGGER CARD FOR SALE INFO!

 

AKAI S900 vs S950 both machines sound the same. What's the difference between akai s900 and s950? The s950 features a better floppy drive with higher density 1.44 MB, higher sampler rate, optional SCSI and digital interface and memory can be expanded. The S-900 needs OS4 for time stretch function and extra EG2. However the ASK-90 is a must have expansion for analog sequencer and this feature is compatible only to S-900.

 

AKAI S SERIES RELATED FAMILY OVERVIEW:

	S-612 (1985) the legend started here!
	S-700 (1987) upgrade version of S-612 also exists in keyboard version X-7000. It seems that a model called X-3700 was a never-released prototype... or a plain hoax?
	S-950 (1988) is the S-900 updated version keeping same sound. Memory can be expanded to 2.25 MB, disk drive is now HD and DD, second ADSR and different expansion options.
	S-01 (1987) budget sampler, basic display no SCSI. S-20 laptop version and Remix16 (and japanese 88) with improved options and memory.
	S-1000 (1988) 2nd generation cd quality and SCSI S-1100 boosted model comes with many optional boards and HD recording. S-1000KB is the S-1000 keyboard version S-1000PB playback, just plain sample reader.
	S-2000 (1995) budget sampler between s1000 and s3000 series
	S-3000 (1996) 3rd generation. - S3000XL was an update with extra (SCSI, digital) - S2800 cut-down version - S2800I with SCSI standad - S3200 added filter board + optional boards - S3200XL all optional - 3000CD includes a cd player - 3000I with SCSI standard
	S-5000 (1998) 64/128 voices, optional USB, digital I/O. S-6000 was even bigger with some standard option and detacheable display, last of the S series then replaced hen by Z family like Z4 and Z8.

 

 

VST PLUGIN / SAMPLED VERSION some free samples disk resources and some plugins, however there are no official PLUGIN version of S900 sampler, but some interesting related programs:

	s900 S950 Soundlibrary Image DISKS FREE!	n/a
	AKAIZER FREE

 

AUDIO DEMO

Disk SL-516 "Ooos" choir Disk SL-515 "Glass Bell" Disk PSL9046 "Hammond" Disk PSL9005 "moog" with cutoff demo Disk PSL9025 "Linn drum" Disk SL-554 "Latin percussions"

Sampling with DSI TEMPEST Sampling with Commodore 64 Sampling with ROLAND TR-909 Sampling with YAMAHA DX-7   Contribute please do send yourS900 beats

 

VIDEO SELECTION - Beat Making Vintage Sampler Demo VIDEO MANUAL

 

 

 

S900 / S950
Free disk images
Exchange club page

MANUAL

SERVICE MANUAL

original brochure

original brochure

original brochure

original brochure

OS CRASH !

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