Talk:E-mu SP-12

Requested move
I believe that my article is relevant because it helped define digital sampling as we know it. The peer reviews that i received told me to go live.

Optronix10 (talk) 04:53, 4 May 2011 (UTC)

Requested move
User:Optronix10/E-mu Sp-12 → E-mu SP-12 — Relisted. Jenks24 (talk) 21:12, 17 May 2011 (UTC) I feel my article is ready to go live and that the E-mu is often regarded as one of the first commercially successful digital samplers that helped open the door on the way sampling is used in rap music today. Optronix10 (talk) 17:33, 4 May 2011 (UTC) ✅--Kotniski (talk) 09:02, 25 May 2011 (UTC)

better picture of the SP-12?
nobody has a better picture of the SP-12 that can be added? the retouched image being used for the header of this article is pretty terrible. Tom (talk) 16:48, 21 February 2013 (UTC)

Sampling Rate
There are now five highly reputable sources cited, including a disambiguation from E-mu co-founder and original SP-12 and SP-1200 designer Dave Rossum provided on this specific subject for the 2011 book SP-1200: The Art and Science (on page 60).

Dave is quoted:

“I don’t know where the rumour started that there was a different sample rate between the SP-12 and the SP-1200? I haven’t been able to find a set of SP-12 schematics to absolutely confirm it, but the sample rate of the Drumulator was 26.04 kHz (5 MHz divided by 6*32), and the SP-1200 is the same (20MHz divided by 3*256), so I’m pretty sure the SP-12 was the same as well. That rate was chosen in the early Drumulator R&D days as a good compromise between perceived audio bandwidth (high end) and total sample time.”

(Though there may have been an unfortunate error in a version of an SP-12 owner's manual, the fact remains that the sample rates are certainly the same between the SP-12 and SP-1200.)

The schematics clearly show that the instruments are the same in the area that generates the channel counter (which must be the sample rate). The only difference is the SP-12 used a 74HCT163, the SP-1200 a 74S163, they are functionally the same).

Also one can see that the 20MHz crystal oscillator is divided by 3 by the 74HCT74s, then by 8 stages of divide-by-2 in the '163 counters. This can be calculated as 20,000,000Hz/3/256 = 26,041 2/3Hz (26,041.666666...Hz), the correct sample rate.

That circuitry cannot generate the claimed SP-12 27,500Hz sample rate. That would require a divisor of (20,000,000/27,500 = 727.272727... = 8000/11), which is clearly not not possible with the simple circuitry present.

Also, when E-mu updated the SP-12 to the SP-1200, E-mu provided ways for users to transfer their SP-12 sounds. They would have all played back at a noticeably wrong rate, and would have been terribly off-pitch (and there would have been a huge upset) had they not been the same sample rate. It would not have made sense to change the sample rate between the SP-12 and SP-1200.

If one has both an SP-12 and an original SP-1200, they can transfer a sample from the SP-12 to the SP-1200 via the cassette interface, and observe that there is no pitch change (and thus no sample rate change). Vactrol (talk) 05:19, 5 July 2024 (UTC)