System-100 Model-101 & 102 in eurorack

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Modulart_JP
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System-100 Model-101 & 102 in eurorack

Post by Modulart_JP » Mon Dec 03, 2018 8:15 am

I have been working on this for quite some time now and everything is finally ready.
It all started a few months back when I was thinking about how I missed my System-100 Model-101 & 102 and how I liked the filter of those synths.
I could buy them again but these days the prices for those antiques are just silly.
Then I thought I could make a clone of that filter for my modular.
But then I thought that I liked the VCO too... :roll:
OK, let's go for a clone of the VCO too.
Eventually I ended up to clone everything... :deadbanana:

The result is 11 modules in eurorack, most of them are 6hp except for the VCO which is 12hp and the VCF, 10hp.
the modules are:
- VCO
- VCF
- VCA
- LFO
- ADSR
- Mixer
- Noise
- S&H
- Ring Mod
- Glide / Portamento
- Inverter / Multiple

I kept most of the original parts: 2SC945-Q, 2SA733-Q, 2SC828-R, 2SK30A, N13T1, etc...
Luckily some local suppliers still carry those parts.
In the VCO, I replaced the uA726 with a well known "discrete" circuit.
Also, it is well known that Roland used a odd matched transistor in the VCF design that I replaced with a AS394 from Erica Synth.

All modules use through hole parts except for 2 IC's on the VCO.

I'm quite happy with the result.
I no longer have the original synths to compare but everything sounds and behaves the way I remember the old ones did.
And that's good enough for me. :guinness:

I was not quite sure what to do with this project.
But I decided to sell PCBs only.
I'll add them to my shop soon.
The BOMs will be available for download as well as FPD & DXF files for the panels.

Pictures of the PCBs and assembled modules to follow.
Demos as soon as I find the time to make some... :ripbanana:

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tron23
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Post by tron23 » Mon Dec 03, 2018 8:42 am

I remember to like System 100 model 101 the most out of the Roland monos I have tried in all the years. What a great project you have completed right there. :guinness:

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Jaytee
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Post by Jaytee » Mon Dec 03, 2018 9:54 am

Oh wow, I was just wondering a week or two ago why we haven’t seen these in DIY.

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Post by mome rath » Mon Dec 03, 2018 10:04 am

Jaytee wrote:Oh wow, I was just wondering a week or two ago why we haven’t seen these in DIY.
are the FCUK system X modules not the same thing?
suppose I'm not well versed in the roland modular stuff
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Jaytee
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Post by Jaytee » Mon Dec 03, 2018 11:04 am

mome rath wrote:
Jaytee wrote:Oh wow, I was just wondering a week or two ago why we haven’t seen these in DIY.
are the FCUK system X modules not the same thing?
suppose I'm not well versed in the roland modular stuff
Confusingly, Roland System 100 and Roland System 100m are not the same.

That said, I have no idea how much the circuitry differs between the two.

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Isaiah
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Post by Isaiah » Mon Dec 03, 2018 11:22 am

Nice!
Do all the PCBs sit parallel to the panel? Do they all have mounting holes?
What are the dimensions of each PCB?
I’ve been dreaming of a banana-equipped Model 101 and 102 for some time!

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Modulart_JP
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Post by Modulart_JP » Tue Dec 04, 2018 6:50 am

Here we go... :ripbanana:

- SYS-100 VCO:
Image
Image
Image

- SYS-100 VCF:
Image
Image
Image
Image

- SYS-100 VCA:
Image
Image
Image

- SYS-100 S&H:
Image
Image

- SYS-100 Ring Mod:
Image
Image

- SYS-100 Noise:
Image
Image

- SYS-100 Mixer:
Image
Image

- SYS-100 LFO:
Image
Image

- SYS-100 Inverter/Multiple:
Image
Image

- SYS-100 Glide/Portamento:
Image

- SYS-100 ADSR:
Image
Image

The System-100 and System-100M are completely different beasts.
Think more of the System-100 as a modular SH-5 (though with only LP filter) and the System-100M as a modular SH-09/SH-2.

I'll let you know when PCBs are available for sale in my shop.
I think the price will be around 5 USD for 6HP modules single PCBs and 10 USD for 10HP/12HP modules PCB sets (2 PCBs/set).

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Post by Purveyor2 » Tue Dec 04, 2018 4:59 pm

you gonna sell panels too?

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Post by maltemark » Tue Dec 04, 2018 5:03 pm

Yeeeesssssss!!!!

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Post by OIP » Tue Dec 04, 2018 6:00 pm

awesome! i will grab the filter when they go up and maybe some others too

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Post by tobb » Wed Dec 05, 2018 5:50 am

Modulart_JP wrote:
The System-100 and System-100M are completely different beasts.
Think more of the System-100 as a modular SH-5 (though with only LP filter) and the System-100M as a modular SH-09/SH-2.
Not really ,a System 100M does not sound at all like a SH-09 or SH-02,so i wander where you get that lol.

Its like the 100M that shares some same circuitry like the System 700 but both systems sounds completely different.(but on top System 700 had two versions of VCA's,one with BA's and one with CA's).

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Post by ndf » Wed Dec 05, 2018 6:07 am

OUROBOROS :)

This is brilliant! I can't wait to build some.

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Modulart_JP
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Post by Modulart_JP » Wed Dec 05, 2018 7:18 am

tobb wrote:
Modulart_JP wrote:
The System-100 and System-100M are completely different beasts.
Think more of the System-100 as a modular SH-5 (though with only LP filter) and the System-100M as a modular SH-09/SH-2.
Not really ,a System 100M does not sound at all like a SH-09 or SH-02,so i wander where you get that lol.

Its like the 100M that shares some same circuitry like the System 700 but both systems sounds completely different.(but on top System 700 had two versions of VCA's,one with BA's and one with CA's).
Well I was talking circuit design, not sound.
And I'm afraid you don't know System-100M, SH-09/2 and System-700 very well otherwise you would know that the design and components used in the 100M are closer to the small SH synths than the mighty 700.
But this is not really the thread for such unproductive debate...
Let's move on. :tu:

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Post by Bamboombaps » Wed Dec 05, 2018 7:26 am

put the panels in the mix and im sold, pcb material even and this will be an awesome cheap build

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Post by haudelukas » Wed Dec 05, 2018 1:01 pm

I was waiting for this for so long! :love: I will buy 3 Oscilators, 3 Filters and i need 1 new case :doh:

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Post by leeski » Wed Dec 05, 2018 1:28 pm

:wow: :eyes:
«:::A:::» «:::W:::» «:::E:::» «:::S:::» «:::O:::» «:::M:::» «:::E:::»

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rosch
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Post by rosch » Wed Dec 05, 2018 2:24 pm

Will you keep it available or only a short run?
This would be material for a small dedicated cabinet. Great looks!

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Post by Isaiah » Thu Dec 06, 2018 5:19 am

Modulart_JP
The VCO and VCF look like they’ll be suitable for formats other than Eurorack due to the inclusion of mounting holes.
I’m wondering how I could include the VCA, ADSR etc though...

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Post by Modulart_JP » Thu Dec 06, 2018 7:58 am

rosch wrote:Will you keep it available or only a short run?
This would be material for a small dedicated cabinet. Great looks!
For sure, the PCBs will be available.
I have received many requests for panel/PCB sets as well as assembled modules.
Therefore I have decided to make a run of them as pre-order.
Then I'll see how things turn out.
Isaiah wrote:The VCO and VCF look like they’ll be suitable for formats other than Eurorack due to the inclusion of mounting holes.
I’m wondering how I could include the VCA, ADSR etc though...
You might use the pads for the pot brackets since they have only a mechanical function.
But often they are close to components or tracks therefore it would be wise to use nylon standoffs as well as nylon screws.
For the modules without pots, you may try to use the holes under the jack sockets.
The closest pad to the hole is the switch of the jack and it's almost never used.
Again, if you use nylon standoffs and screws, it should be OK.
And the noise has a mounting hole.
I had to add one for mechanical reasons.

Here is what a system equivalent to a Model-101 looks like:
Image
The only thing missing is the Glide/Portamento because I have not received the front panel yet.

A system equivalent to a Model-102:
Image

Everything is now available in my shop here:
https://www.pharmasonic.jp/shop/index.p ... r=category

The PCBs are in stock and can ship right away.
On the PCB pages, you'll find the BOM, DXF and FPD files.

Since I was not expecting to sell modules or panels, they are available only as pre-order. (I didn't stock parts or panels)
With the end of the year coming soon, I'm afraid nothing will be able to ship before mid-January.

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Post by tobb » Thu Dec 06, 2018 8:12 am

Modulart_JP wrote:
Well I was talking circuit design, not sound.
And I'm afraid you don't know System-100M, SH-09/2 and System-700 very well otherwise you would know that the design and components used in the 100M are closer to the small SH synths than the mighty 700.
But this is not really the thread for such unproductive debate...
Let's move on. :tu:
I have had all of them and know better then any who's not owned them how the sound!

No matter the thread ,its important for for ppl to know a 100M does not sound like at all like a SH-09 or SH-2,so you statement can be totally misleading,so it important to mention it.

Btw,the 100M share plenty circuitry from the 700 to.

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Post by Modulart_JP » Thu Dec 06, 2018 9:22 am

I have had all of them and know better then any who's not owned them how the sound!
Hahaha ! You don't know what I owned or not.
If you knew you would not say things like that.
For your record I know all those synths (including the 700) inside out very well.
If you want to continue talking about it, PM me.
But don't troll this thread.

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Post by Branko » Thu Dec 06, 2018 10:31 am

Just ordered a bunch of PCBs. Stoked! Gonna start designing some panels! Thanks for making this available.

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Post by Bartelby » Thu Dec 06, 2018 10:57 am

Is the price right for the ring mod panel. Y14,000 seems a little pricey :)

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Post by Branko » Thu Dec 06, 2018 3:16 pm

Had some fun in anticipation:

Image

I still gotta tweak some stuff (kerning and font sizes) but I like where I got!

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Post by Modulart_JP » Fri Dec 07, 2018 1:16 am

Very nice indeed !
But you might have a problem with the S&H's FREQ pot... :lol:

On the PCB pages, I have added a link to Mouser carts for common parts.

Some info about some technical aspects...

1) The ADSR uses the rare N13T1 PUT.
I have some and therefore used them to build my modules.
The 2N6027 is a drop in replacement however I have not tested it and cannot confirm that the ADSR will behave exactly as with a N13T1.

2) The ADSR envelope again...
TBH, the System-100 envelope generator is not the best around.
But my goal was not to enhance or upgrade anything, it was to make it as close as possible to the original.
Therefore the modules of this project come with the pros AND the cons of the System-100 design.
One of the cons is the threshold of the envelope.
Simply put, it won't work correctly with a 5V gate/trig.
I guess the threshold is around 8/9V.
It works well with my Beatstep Pro and a 10V gate.

3) As said before, I had to replace the infamous uA726 in the VCO design with a "discrete" equivalent.
The circuit uses SMD parts in order to get the components at the right temperature faster.
But still the VCO will drift for a few minutes when you switch it on.
Once it has warmed up, it is pretty stable.

4) You can use the System-100 Model-101 & model-102's service manuals for the calibration of all the modules.
The only difference is with the VCO.
There is one more trimmer to calibrate the "uA726" circuit.
I'll make a little guide in PDF for that soon.
Is the price right for the ring mod panel. Y14,000 seems a little pricey smile
Yes, a mistake indeed.
Thank you for pointing it out. :tu:
It's fixed.

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