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2003-10-02 by combatwombat12
Does anyone have any comments on this. I am thinking of buying either to go with my MPC 3000 and SP12. What are the advantages of either one. What is sampling bass like through the EMAX. The emax is 12bit isnt it. marc
2003-10-02 by John Silveria
They are both 12bit.
As far as the sound, my memory is that the S950 made more accurate samples. eg - the
sample sounded more like a recording of the input, as to where the E-mu line seems to
have a more discernable fingerprint left in the sound. But the S950 filter was not
anywhere near as phat and warm as the Emax, but then again what is :) The other thing
was the S950, though I remember it being available as a keyboard, was mostly a rack
unit.
The Akai has some advantages over an Emax, up to 2.25 MB of Memory (750k
stock) and an optional external SCSI, accepts HD diskettes, and there was
15,000 made which means a larger user base. Also it samples at up to 48
kHz.
But, if you want to make BASS samples the E-mu is going to be the hands
down winner when it comes to actual sound. The Emax makes great warm and
phat bass sounds
On 2 Oct 2003 at 7:14, combatwombat12 spoke unto me:
> Does anyone have any comments on this. I am thinking of buying either to
> go with my MPC 3000 and SP12. What are the advantages of either one.
> What is sampling bass like through the EMAX. The emax is 12bit isnt it.
> marc
>
>
On 2 Oct 2003 at 7:14, combatwombat12 spoke unto me:
> Does anyone have any comments on this. I am thinking of buying either
> to go with my MPC 3000 and SP12. What are the advantages of either
> one. What is sampling bass like through the EMAX. The emax is 12bit
> isnt it. marc
>
>
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------------------ http://www.silveriafamily.com ----------------------2003-10-02 by capricorn
the original emax(I) is 12bit the emax II is 16 bit
----- Original Message -----
From: combatwombat12
To: emax@yahoogroups.com
Sent: Thursday, October 02, 2003 2:14 AM
Subject: [emax] EMAX HD SE v's AKAI S950
Does anyone have any comments on this. I am thinking of buying either
to go with my MPC 3000 and SP12. What are the advantages of either
one. What is sampling bass like through the EMAX. The emax is 12bit
isnt it.
marc
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[Non-text portions of this message have been removed]2003-10-02 by Rob Keeble
Hi, Emax is usally considered to be 12-bits because thats the resolution of the ADC/DAC''s and thats the resolution of sample stored to disk. However the Emax sample replay chip uses 16-bit audio data, 24-bits in the DSP to maintain 16-bit precision, and manipulates samples that are compressed into 8-bits. All rather confusing ! And all done with 50,000 transistors. The bottom line is Dave Rossum designed quite an effective sample replay chip with some neat DSP tricks to reduce pitch shift distortion (for 12-bits....). Not at all like a 12-bit linear sampler like the Akai S900, and well worth using even today. The Emax was designed to sound good, rather have great technical specs. Regards Rob The emax is 12bit isnt it. [Non-text portions of this message have been removed]
2003-10-04 by tbiggz
> chip with some neat DSP tricks to reduce pitch shift distortion (for > 12-bits....). Not at all like a 12-bit linear sampler like the Akai Strange. Everyone I know who's interested in the Emax, likes the way the emax mangles samples during pitch shifting. The draw is that this is the closest thing to SP-12/1200 pitch shifting. I don't know for sure, but I imagine the circuit for pitch shifting in the SP is to simply repeat or drop samples as needed to produce the required pitch change at a fixed sample playback clock. This would account for the square wave sound on top of the pitched SP samples. However, this requires no dsp power whatsoever, other than an adder with some fractional precision. So although all the other stuff in the Emax might be complicated, I never imagined the pitch shifting would be complicated. Is that true? BTW I have an S950 and the pitch shifting on it (not to be confused with time stretching) is fine. I never notice artifacts like on the SP.
2003-10-04 by Rob Keeble
Hi,
The Emax uses a fixed rate sample replay algorithm and therefore drops/adds
samples, just like the SP's. However the E chip within the Emax is
considerably more complex than the TTL chip based micro controller in the
SP's, as it deals with different sample rates, as well as
compression/expansion of the samples. The Emax sample engine is good for
keyboards as it pitch shifts (down) reasonably well, the SP engine is for
drum samples where good quality pitch shifting is not important. The SP
sample replay engine is the same as the Drumulator, as are all the filters.
The E chip is only a basic DSP, and the SE sample manipulation features run
on the main processor. The E-chip is a custom DSP chip which manipulates 16
channels of digital audio. The chip performs three main jobs:
1) It replays the samples from memory and pitch shifts them as necessary
using a fixed sample replay rate that adds and drops samples to achieve the
transposition in pitch. It understands the sample rate of the sample.
2) It translates the 8-bit samples that are held in sample memory back into
12-bit samples ready for conversion back into an audio signal.
3) It adjusts the volume of each individual sample as required by the patch,
although the final VCA is in the analog filter chip. Overall sample volume
and modulation from the LFO is set by the E-chip.
The Akai S950 (variable rate) and Emax have very different frequency
responses, with the Akai having 5dB boost from 3.5kHz to 21kHz, whilst the
Emax drops 9dB at 18kHz. The Akai has much less pitch shift distortion, but
the Emax distortion is due to the compression/expansion of samples more than
shifting, which also affects dynamic range. The E chip may also be over
sampling, but the precise design is confidential.
An Emax and SP do sound similar because they are much closer in design than
an E-mu and Japanese sampler. The technical specs of the Emax are inferior
to the Akai, but musicians often prefer the sound of the Emax.
Hope this helps!
Rob
www.emulatorarchive.com
Strange. Everyone I know who's interested in the Emax, likes the way
the emax mangles samples during pitch shifting. The draw is that
this is the closest thing to SP-12/1200 pitch shifting.
I don't know for sure, but I imagine the circuit for pitch shifting
in the SP is to simply repeat or drop samples as needed to produce
the required pitch change at a fixed sample playback clock. This
would account for the square wave sound on top of the pitched SP
samples. However, this requires no dsp power whatsoever, other than
an adder with some fractional precision. So although all the other
stuff in the Emax might be complicated, I never imagined the pitch
shifting would be complicated. Is that true?
BTW I have an S950 and the pitch shifting on it (not to be confused
with time stretching) is fine. I never notice artifacts like on the
SP.
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[Non-text portions of this message have been removed]2003-10-04 by tbiggz
--- In emax@yahoogroups.com, "Rob Keeble" <rob@e...> wrote: > channels of digital audio. The chip performs three main jobs: > > 1) It replays the samples from memory and pitch shifts them as necessary > using a fixed sample replay rate that adds and drops samples to achieve the > transposition in pitch. It understands the sample rate of the sample. Well, that would account for the distortion. From what little I know, adding/dropping samples is a poor method of resampling. With a single multiplier op, one can do at least linear interpolation where samples will sound smoother. I'm not complaining, I love the pitch- down/up artifacts on my SP. I imagine emax owners love their artifacts too. > The Akai S950 (variable rate) and Emax have very different frequency > responses, with the Akai having 5dB boost from 3.5kHz to 21kHz, whilst the > Emax drops 9dB at 18kHz. I didn't know that! Why does akai do that? Is their input filter this bad? The Emax spec makes more sense to me. > the Emax distortion is due to the compression/expansion of samples more than > shifting, which also affects dynamic range. The E chip may also be over > sampling, but the precise design is confidential. Ok, so the resampling/pitch shifting is not the culprit!? So that may be the difference between the SP and the Emax. At zero pitch shift on the SP, the sample exhibits no distortion of the kind heard when pitch-shifting. I would have imagined that the Emax was the same; only introducing artifacts when pitch-shifting. If the compression algo does this much damage, I would guess that the Emax plays back with distortion even at the root key. Is that true? BTW Rob, thanks for the indepth responses. These are super interesting!