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I'm building an SP-1200 clone with a few extra features Drum Machines & Samplers
Old 2 weeks ago
  #31
Lives for gear
Will you selling this as DIY kits?
Old 2 weeks ago
  #32
Here for the gear
 

Get that kickstarter going!
Old 2 weeks ago
  #33
Gear Maniac
Quote:
Originally Posted by living sounds View Post
Nobody has nailed the sound so far. Maybe the transpose algorithm and its artifacts, but not the converter/analog part. For me that part was a major reason to get another SP and consider it really important. The lossy power supply might have something to do with it as well. Luckily, identical components or adaquaete substitutes for everything should be availible.
yes they have
take a look/listen at Rossum Assimil8tor, from the original designer of the SP12/00

you can go to drop sample behavior (and beyond) and bit 'crush' (variable!) down to 1bit

esp. when loaded with SP12 / drumulator samples (i use SOX program to convert samples to original 26/28Khz rate) i get lovely comments on how punchy the sound is - what helps and really makes a difference is to filter/send the sounds through a SSM doepfer A105, even with fully opened freq.

Assimil8or
Old 2 weeks ago
  #34
Gear Addict
 

Quote:
Originally Posted by tiger001 View Post
yes they have
take a look/listen at Rossum Assimil8tor, from the original designer of the SP12/00

you can go to drop sample behavior (and beyond) and bit 'crush' (variable!) down to 1bit

esp. when loaded with SP12 / drumulator samples (i use SOX program to convert samples to original 26/28Khz rate) i get lovely comments on how punchy the sound is - what helps and really makes a difference is to filter/send the sounds through a SSM doepfer A105, even with fully opened freq.

Assimil8or
The Assimil8tor isn’t even close to being 12 bits nor trying to be. It has 24 bit ADs and DAs.
Old 2 weeks ago
  #35
Gear Maniac
true, it can do High fidelity too

from the manual : Bit Depth

This parameter lets you hear your sample as it would sound if it were stored at bit depths of from 32.0 bits down to 1.0 bit. Resolution is 1 bit from 10.0 to 32.0 bits and 0.1 bit from 1.0 to 10.0 bits. (That’s right, you can finally hear what a 5.3 bit format would sound like.)NOTE: Playing with this parameter will demonstrate that the difference between high and medium bit depths are really quite subtle. If you really want to destroy your sounds, start around 6 bits or so and head down from there.
ANOTHER NOTE: It’s a good idea to turn down the volume before exploring the lowest bit depths. As you get down to 1 bit, you’ll get to the point where your sound is
just a full-level square wave. A LOUD full-level square wave. Be careful.Bit Depth can be modulated by any of the CV inputs with the modulation gain set by the associated attenuverter. The gain range is from -3.20 bits per volt to +3.20 bits per volt.
Old 2 weeks ago
  #36
Gear Nut
 
dahkter's Avatar
 

Great work so far!

My feedback:
Sequencer feel is key. Think "Music Sounds Better With You". I believe the SP1200 used a Z80 chip. If you can have the Arudino mimic this behavior, possibly you can duplicate it.

Sound is important as well. I recall the kicks, snares and hats on the SP being beefy and rubbery and larger than the sample source. Possibly some EQ/Compression/Envelopes to mimic this. Re the aliasing sound, the TAL SAMPLER (and the TAL DAC) has done the best job of any software I've used at nailing this.

Really happy to see you doing this, I miss my SP (had two, sold one, traded the other). Now that you can buy a decent car for the cost of an SP1200, it's definitely high time for someone to duplicate it. On that note, does anyone know why eMU or Dave Rossum don't just remake the SP? Originally they claimed the filter chips were hard to get, however like others in this post, I never cared for or used the SP filters. Additionaly, you can now get clone chips to rebuild this machine.

Update: I sent a message to Dave Rossum, will advise if he replies. Thanks.
Old 2 weeks ago
  #37
Gear Head
I agree about the sequencer feel, but it's not nearly as magical as most people think. Dave Rossum breaks it down himself in that interview about the SP that's on YouTube.

I think the main factors are:
- The 24ppq resolution of the sequencer, which is basically already quantizing your drum hits, that's already implemented in my prototype
- The slight jitter which makes it so that not every hit is perfectly on time (the drift is only about +/-2ms), again easy to do that on purpose
- The swing templates, which are easy enough to reproduce

I also have on-the-fly bit depth reduction from 12bits to 1bit done, there's a video of that on my IG.

Dave Rossum said he isn't remaking the SP for various reasons, for one he doesn't have the rights to the Emu brand anymore, Creative has them. For two, he says he likes to go forward and not backwards, in so many words. I think another major factor is how niche a product like this is, it probably wouldn't make sense financially for a full-on established company to do.
Old 2 weeks ago
  #38
Gear Nut
 
dahkter's Avatar
 

Quote:
Originally Posted by Low Hiss View Post
I think the main factors are:
- The 24ppq resolution of the sequencer, which is basically already quantizing your drum hits, that's already implemented in my prototype
- The slight jitter which makes it so that not every hit is perfectly on time (the drift is only about +/-2ms), again easy to do that on purpose
- The swing templates, which are easy enough to reproduce

I also have on-the-fly bit depth reduction from 12bits to 1bit done, there's a video of that on my IG.

Dave Rossum said he isn't remaking the SP for various reasons, for one he doesn't have the rights to the Emu brand anymore, Creative has them. For two, he says he likes to go forward and not backwards, in so many words. I think another major factor is how niche a product like this is, it probably wouldn't make sense financially for a full-on established company to do.
Thanks for your reply, all sounding great.
If you can make that sequencer bounce like Craig Mack Flava in Ya Ear, I will salute you like a 5 Star General.

Re Rossum Electronics, they did reply, here is their feedback:
"As you guess, we have received quite a bit of interest in the possibility of some SP-1200 follow-on from us. While we haven’t committed to anything, we are actively discussing the possibilities. No promises, but watch for any future news."
Old 2 weeks ago
  #39
Lives for gear
 
Cornish1999's Avatar
^ O.M.G!
Old 2 weeks ago
  #40
Gear Head
damn, this looks interesting as hell!
would also be interested in somehow getting one of these
Old 2 weeks ago
  #41
Gear Addict
 

I hope Rossum understands a modern take on the SP, such as a 24-bit drum machine, would somewhat miss the purpose.

What has kept many back from modifying current SPs has been how protected its code is and that the original source code has been “lost”.
Old 2 weeks ago
  #42
I'm in! Project looks amazing! Hope for a Kickstarter campaign
Old 2 weeks ago
  #43
Gear Head
Thanks guys. Crowdfunding does seem like a good option but I need to make sure it doesn't cost me a lawsuit before I do anything, I don't know US law.

Judging by how similar the behringer 808 clone is I have good faith that I can sell SP clones legally, I just need to know exactly which lines I can't cross basically.
Old 2 weeks ago
  #44
Lives for gear
 
the fxs's Avatar
 

well, not putting an EMU logo or the "SP1200" name on it will certainly help you not to get sued.
Old 2 weeks ago
  #45
Gear Nut
 

isn't behringer working on one as well?
Old 2 weeks ago
  #46
Gear Head
Quote:
Originally Posted by 808BD View Post
isn't behringer working on one as well?
I highly doubt it, the only thing on the subject is this thread which is just a bunch of people's wishful thinking it seems: Behringer BP-1200 Sampling Drum Machine (in 2019?)

This post sums it up: Behringer BP-1200 Sampling Drum Machine (in 2019?)


Quote:
Originally Posted by the fxs View Post
well, not putting an EMU logo or the "SP1200" name on it will certainly help you not to get sued.
Well of course, that goes without saying, but I'm sure there are some finer details.
Old 2 weeks ago
  #47
Gear Head
or you can follow a strategy similar to these dudes who sell a roland tb 303 clone

for example: make a pcb and bundle it with all the necessary things needed (buttons, cables, potentiometers, raspberry)
but sell the case separately
Old 2 weeks ago
  #48
Gear Maniac
Quote:
Originally Posted by Low Hiss View Post
Well of course, that goes without saying, but I'm sure there are some finer details.
Maybe reach out to Dave Rossum's company directly ?


http://www.rossum-electro.com

Last edited by eqverb; 2 weeks ago at 05:40 PM.. Reason: .
Old 2 weeks ago
  #49
Here for the gear
This is wicked cool man! nice build!
Old 2 weeks ago
  #50
Gear Head
Quote:
Originally Posted by eqverb View Post
Maybe reach out to Dave Rossum's company directly ?

http://www.rossum-electro.com
I will contact Dave Rossum but I wanna wait until I have something a bit more presentable.
I'm in indirect contact with a former Emu engineer who's on the credits for the SP in the manual, through an online friend who happens to be his neighbor, and who bought the one of a kind prototype of the black reissue he had laying around at home.
I asked him some questions I should have some answers fairly soon.
Old 2 weeks ago
  #51
Gear Maniac
@ Low_Hiss

Great to hear, I emailed them about a year ago about the Assimil8or and SP1200 questions. Dave signed the email so I have to assume it was him responding directly. He seemed very approachable based on the response.
Old 1 week ago
  #52
Gear Maniac
can you elaborate more about this tantalizing ersatz (the Assimil8tor as a replacement for the SP12/00) please?

maybe here : Rossum Assimil8or - Is it just vaporware at this point?
Old 1 week ago
  #53
Gear Maniac
Quote:
Originally Posted by tiger001 View Post
can you elaborate more about this tantalizing ersatz (the Assimil8tor as a replacement for the SP12/00) please?

maybe here : Rossum Assimil8or - Is it just vaporware at this point?

Hi Tiger,

It's not a replacement just a very interesting sampler in euro-rack form. I was at one point going to take the plunge into modular and really liked the features of Assimil8tor. It was between that and 1010 music bitbox. I was going to pair with a digitakt. I was hoping for the filters or similar filtering of the sp1200, but that wasnt the case.

Last edited by eqverb; 1 week ago at 02:11 PM.. Reason: .
Old 1 week ago
  #54
Gear Maniac
 
KazRemark's Avatar
 

Nice work, I'm down to contribute to Kickstarter.
Old 1 week ago
  #55
Lives for gear
 

Quote:
Originally Posted by tiger001 View Post
yes they have
take a look/listen at Rossum Assimil8tor, from the original designer of the SP12/00

you can go to drop sample behavior (and beyond) and bit 'crush' (variable!) down to 1bit

esp. when loaded with SP12 / drumulator samples (i use SOX program to convert samples to original 26/28Khz rate) i get lovely comments on how punchy the sound is - what helps and really makes a difference is to filter/send the sounds through a SSM doepfer A105, even with fully opened freq.

Assimil8or

A modern sigma delta ADC/DAC running on the modular's PSU is very different from the original SAR / R2R design.

People need to stop focusing on the buzzword "12-bit", since it in itself has very little to do with the specific sound of these old samplers. 12 Bit can be sufficient and pretty much transparent for modern highly compressed music, you get SNR superior to an analog studio tape machine. The "sound" of these samplers lies in specific behaviour that is not related to bit depth.

If I were to clone the SP I would take a hard look at the circuitry and component selection of the PSU, the ADC and the DACs. It is ideosyncratic and needs a fair bit of skill to adjust properly, in the SP-12 (which is not very different in most respects) even more than in the SP1200.
Old 1 week ago
  #56
Gear Head
Quote:
Originally Posted by living sounds View Post
A modern sigma delta ADC/DAC running on the modular's PSU is very different from the original SAR / R2R design.

People need to stop focusing on the buzzword "12-bit", since it in itself has very little to do with the specific sound of these old samplers. 12 Bit can be sufficient and pretty much transparent for modern highly compressed music, you get SNR superior to an analog studio tape machine. The "sound" of these samplers lies in specific behaviour that is not related to bit depth.

If I were to clone the SP I would take a hard look at the circuitry and component selection of the PSU, the ADC and the DACs. It is ideosyncratic and needs a fair bit of skill to adjust properly, in the SP-12 (which is not very different in most respects) even more than in the SP1200.
You are right that the bit depth really doesn't play as big a role as most people think, the difference between 16bit and 12bit is very subtle in most cases.

However you'd be surprised how much of the "sound" actually comes from the digital implementation rather than the analog circuitry. The main thing by far (at least 80%) is the pitch shifting algorithm. I doubt you'd be able to tell two SPs with different PSUs appart (e.g the original and the black reissue for example).

The main analog components that contribute to the sound are the input filter, output filters and op-amps in my opinion.
Again here are some samples downloaded and ran digitally through my implementation of the pitch shifting algorithm: Uploadfiles.io - SP-algorithm-test.zip

And a comparison between the same samples ran through the real thing vs my digital emulation:
Low Hiss on Instagram: “Which bank is the SP and which bank is my copy of its tuning algorithm? Go! I've been busy copying the exact way the SP pitches samples up…”

There's definitely a roll off in the high frequencies on the original but aside from that it's very similar, so much so that a majority of SP users got it wrong in a blind test in the fb group.
Old 1 week ago
  #57
Lives for gear
 

Quote:
Originally Posted by Low Hiss View Post
You are right that the bit depth really doesn't play as big a role as most people think, the difference between 16bit and 12bit is very subtle in most cases.

However you'd be surprised how much of the "sound" actually comes from the digital implementation rather than the analog circuitry. The main thing by far (at least 80%) is the pitch shifting algorithm. I doubt you'd be able to tell two SPs with different PSUs appart (e.g the original and the black reissue for example).

The main analog components that contribute to the sound are the input filter, output filters and op-amps in my opinion.
Again here are some samples downloaded and ran digitally through my implementation of the pitch shifting algorithm: Uploadfiles.io - SP-algorithm-test.zip

And a comparison between the same samples ran through the real thing vs my digital emulation:
Low Hiss on Instagram: “Here are the results from yesterday's experiment. The green bank was my emulation, while the yellow bank was the real thing. Some of y'all…”

There's definitely a roll off in the high frequencies on the original but aside from that it's very similar, so much so that a majority of SP users got it wrong in a blind test in the fb group.
I very often don't even use the pitch transpose in my SP-12. I still find it to add a certain punch to the sound that is impossible to get ITB. I also usually don't use the SSM-filters or TL084 based output filters (I added switches on my SP so I can bypass all the output filters if I like).

I made a SPICE emulation of the input filter and send sound through it, did exactly what you would expect but didn't add the punch.

You can actually send samples via MIDI into the SP and they still get the punch.

So what remains is the DAC and/or related nonlinearities of the analog output stage. There are no VCAs and it works for loops the same as it does for single samples.
Old 1 week ago
  #58
Gear Head
 

Hi Low Hiss,

This is a great project and i, like many others, just can't wait to buy one.
It would be great if a lot of parameters could respond to midi CCs.
Is it something you have on your road map ?
Cheers.
Old 1 week ago
  #59
Gear Head
Quote:
Originally Posted by living sounds View Post
I very often don't even use the pitch transpose in my SP-12. I still find it to add a certain punch to the sound that is impossible to get ITB. I also usually don't use the SSM-filters or TL084 based output filters (I added switches on my SP so I can bypass all the output filters if I like).

I made a SPICE emulation of the input filter and send sound through it, did exactly what you would expect but didn't add the punch.

You can actually send samples via MIDI into the SP and they still get the punch.

So what remains is the DAC and/or related nonlinearities of the analog output stage. There are no VCAs and it works for loops the same as it does for single samples.
Oh for sure the DAC does play a role, that's undeniable, but I think you'll agree that as good as the effect it induces is, it's pretty subtle. Like I said the DAC choice isn't finalized yet, we might very well end up using the AD7541

Quote:
Originally Posted by Js.theracon View Post
Hi Low Hiss,

This is a great project and i, like many others, just can't wait to buy one.
It would be great if a lot of parameters could respond to midi CCs.
Is it something you have on your road map ?
Cheers.
Thanks for the kind words. I haven't started working on the midi implementation yet, so I can't say for sure how much the Pi can and can't handle. That being said I definitely will try to make the implementation as complete as possible.
Old 1 week ago
  #60
Lives for gear
 

Quote:
Originally Posted by Low Hiss View Post
Oh for sure the DAC does play a role, that's undeniable, but I think you'll agree that as good as the effect it induces is, it's pretty subtle. Like I said the DAC choice isn't finalized yet, we might very well end up using the AD7541
When people say the SP "kicks like a mule" it's due to this DA stage, and I wouldn't call that effect subtle.

The AD7541 is fine, I put it my former and my current SP-12. It's probably not the specific DAC chip but rather certain artifacts of the circuit that create the effect.
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