synthmania

first timer builder looking for suggestions

20 posts in this topic

Hi,

I just discovered this new world of SID standalone devices; and want to make my own SID Midibox. I used to have a C64 when I was a kid, and never got any idea how electronics did work, but with time got more and more into it; until the point where I became a programmer.

Searching in the attic of a relative I found a treasure of old hardware; like Amiga 600, a C64, an Atari 2600 and few other computers that for today standards they are fundamentally ancient. While nothing beside the 2600 was working; I found that people were using the SID in the C64 to make synths, and since I am a big synth nutcase, I thought why not trying putting together a midibox.

I did check the various solutions out there, and what did strike me is the fact that most implementation goes pretty low to the metal; while in some cases I saw people using Arduino or even Raspberry Pi to control the SID; so I was wondering if there is a "newer" way to make a midibox SID, using such devices, which offer native support for things like Midi, serial and usb; and has an easy to use IDE (like for the arduino IDE), that can be programmed in C and it is pretty straightforward.

I am OK going for the standard implementation but was wondering if there was a reason for not using something more "complete" like an arduino/ARM micro, or even a RPI, to drive the SID chip (not planning to build the whole thing, that is way out of my league; but I would be happy to at least get some sound out of the chip, and maybe control it via standard midi CC signals to give some retro-vibe to my music compositions).

Thanks!

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I'm not a pro but heard using an arduino for building midi/sound devices isn't "the weapon of choice" it's just very populated, documented and easy to get.

(I say how I see this, someone with better knowledge correct me if I am wrong)

Also, the design is old, there wasn't much more other solutions at this time but still good enough, today.

Today, TK may would use the Core stfm 32, but I think it's just not necessary.

The Midibox project is a detailed documented gift for others to build this devices in the way the inventer choose it. If there is nobody porting the stuff to other solutions, document it and share it with others, there is no other but it is, sure, possible. 

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Yep, noise generator is right, the design for SID control is old but still very complete. If you follow the diagram and he "how to" you will quickly get some result, and get some good vibes from your SID, with CC etc...
You can also find some clean board at Modular Addict. CORE8 + SID Module.
Migrate the firmware to an ARM like arduino is an hard work, and you will not be able to use the MIOS Studio which is very usefull to program your patches etc...

Best regards
Bruno
 

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Thanks for your reply; from what I can tell, there is not much about using arduino for builds; I just found few videos that were not even going in details about the process; hence my curiosity to know if that was the new way to make the midibox.

I am OK with using the original design; I just wonder why it was not updated, and the assumption that it is much easier to find the parts in the list for the barebone board, compared to support a commercial product like an arduino. Also I assume that it has to be hard to make, so nobody mass-produce it (as it happened with other designs that started as hobby/maker projects and became commercial).

Also good point on not having the MIOS studio at that point; I wrote few midi programs to interface with my hardware, so I am not totally new to the process, but having something that is solid is a great starting point.

I will give it a try :) I guess nobody made a video tutorial about how to go by with the build, right? :) Also what would you consider pitfalls for the build? Beside voltage (12V for the SID and 5V for VCC if I recall correctly from the schematics)?

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4 hours ago, synthmania said:

I will give it a try :) I guess nobody made a video tutorial about how to go by with the build, right? :) Also what would you consider pitfalls for the build? Beside voltage (12V for the SID and 5V for VCC if I recall correctly from the schematics)?

 

If you’re going to build an MB-6582, I’d suggest following the guide for Power supply option E. This uses a standard 12VDC wall wart and swaps out the 7805 for a switching regulator. Your synth will run very efficiently and barely give off any heat. You can completely ditch the fan. 
 

As far as lessons learned go, if you scan through the posts in this forum, you’ll see some areas I struggled with. Learning to program the PICs and change device, etc. took me a while, but it’s actually a pretty straight forward process. Getting the JB Weld ‘just right’ for the front panel takes some practice and patience as well.
 

Everything you need is well documented and easily searchable, so look around and don’t hesitate to ask...

 

 

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Posted (edited)

Thanks a lot! Will probably give it a go this weekend, once all the electronic parts will arrive (these days it is hard to go to a store to grab components).

BTW I have a question regarding the sammich box; which from what I understand, is a variant of the original midibox. Not sure if it is kosher to talk about it here, so I want to point out that I am not aware if there is any negative history about this box or not.

I noticed that the sammich use 2 SID; which is kinda weird; is there a particular reason for using 2 of them? I thought each SID is a 3 voices stereo device, so adding 2 give you 6 voices? Also considering that it takes 2 SID; does it matter if you use SID of different revision, like 4982, 2282 and so on? Being made in the same year should guarantee a consistent sound I believe.

Edited by synthmania

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Posted (edited)

On 5/13/2020 at 7:30 PM, synthmania said:

thought each SID is a 3 voices stereo device, so adding 2 give you 6 voices? 

that's the bit that's confused, each chip is 3 voice mono - so pairs are used to create stereo.

I think it's unlikely you'll get two SID chips that sound identical no matter if they're from the same day in the same factory really, they were a bit variable to begin with and they're now 30-40 years old. 8580s are apparently a lot less varied than the 6581s though...... As long as they're in the same ballpark the differences just tend to make them sound wider (and pretty great). I don't think worrying about which year/factory they were produced in is too important (and will be difficult now anyway as the supply of them is not great!) Having said that I did try to pair mine based on the dates on them, so I get the inclination to do so!

Edited by the_duckchild
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Posted (edited)

Polyphony is another reason, take a look at the Menu Guide to get all Infos.

The sammichSID design is great and compact, you just can't buy it anymore because it is a design of a user named wilba and he didn't released the pcbs for open source as far as I know. But it is "nothing" more than some separate modules put in one mainboard.

Edited by Noise-Generator
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Thanks for the clarifications! So it is fundamentally a core with 2 SID modules then? I looked around and the prices for the few on the market are insanely high. The other alternative is ebay kits; which I assume are not "original", if the user didn't release kits anymore and he is not selling them from what I can tell. If it was in the 100-150 USD ballpark I may consider it; but I see that ModularAddict sell the PCB already, so that is a more practical way to get started I think.

Good point on the SID not being producing the same sound; I was curious why would someone use 2 in stereo, but since each chip has 3 voices mono, that make sense.

Would you say that to start, I should get the PCB from https://modularaddict.com/manufacturer/midibox ? I have no clue how to work with PCB, I can make breadboard circuits but that's the extent of it; having a PCB that is well made is probably the best route for me. I was planning to order the SID module, but there are 2 core modules; there is MB6582 - SID synth main PCB and Core8 PCB.Then I need the midi module too I assume, to be able to have the box to talk to my computer.

 

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If you’re not comfortable soldering (and troubleshooting) a full sized set of PCB yet, then you could do what @Noise-Generator suggests and work with the individual modules. Although in my humble opinion the final product will come out looking a bit messy with all the ribbon cables joining the boards together, etc.

As an alternative to that, you could consider building a sammichSID kit from eBay (https://www.ebay.com/itm/153859268349). I’ve purchased and built a few of these over the years with no issues. It’s basically a single core module, combined with a single SID module and some bank sticks on one small PCB and a shrunken down, but still very usable control surface on another. It’s functionally complete and it let’s you fully experience the MIDIBox SID v2. It uses the same sound patches as the MB-6582, etc.

The seller is based in China, so the kit could take a few weeks to arrive, but it comes complete with everything you need, including the PCBs, all discrete components, a couple SwinSIDs, which are much cheaper than real SID chips, a decent metal case, a power supply, etc. 

Following the build guide(http://www.midibox.org/dokuwiki/doku.php?id=sammichSID#sammichSID_build_guide), you can probably complete the whole thing and be up and playing within ~5-6 hours.

Cheers

 

 

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Thanks; I read the manual but it is not a step by step manual, so it is more of a guideline about how to do things, and there are no reference to pre-made PCB ; that's why I was asking (there is a broken link referring to a kit, that's all I was able to find on the manual).

Since I want to try all solutions, I did order the PCBs AND got the sammichSID kit; hopefully it will arrive soon, since I paid for expedite shipping. I have 2 6581 so I can use one for each project and see which one works best for me; got all the components monday, so I can do all 3 implementations at this point and see which works best for me.

@dwestbury I was told that sammichSID has a different interface, even if it is using MIOS; in fact I saw that it has a row of buttons that is blank (I assume those are the #1 to #5 buttons for options, there is no label on them from the picture I saw), and a second row with F1 F2 and F3; the midibox V2 manual does not seem to have any reference to these. The other side has the shift, menu, and top-bottom buttons; which are in the manual. Is there a sammich manual beside the build guide?

Also as side note; using 6581, the manual warns about leakage of the sound after pressing a key; how bad is it? Is there a way to solve it? Because if I am recording audio that has leakage and background sound, I can't really do much to fix it (I can fix background noise with the audio tools available these days, but I don't think that will work for actual persistent audio that leak. I won't know until I actually build either solution so I want to be prepared about it

Thanks!

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On 5/20/2020 at 0:56 AM, synthmania said:

@dwestbury was told that sammichSID has a different interface, even if it is using MIOS; in fact I saw that it has a row of buttons that is blank (I assume those are the #1 to #5 buttons for options, there is no label on them from the picture I saw), and a second row with F1 F2 and F3; the midibox V2 manual does not seem to have any reference to these. The other side has the shift, menu, and top-bottom buttons; which are in the manual. Is there a sammich manual beside the build guide?

Also as side note; using 6581, the manual warns about leakage of the sound after pressing a key; how bad is it? Is there a way to solve it? Because if I am recording audio that has leakage and background sound, I can't really do much to fix it (I can fix background noise with the audio tools available these days, but I don't think that will work for actual persistent audio that leak. I won't know until I actually build either solution so I want to be prepared about it

 

Yes, the button layout on the MB-6582 and sammichSID are different, but the main functions you’ll generally need are still accessible on the condensed sammichSID interface. The main difference is really the smaller screen and the missing routing matrix. The interface was really only designed for two rows anyway. The extra rows show secondary info, like scroll bars and progress indicators etc. I realized that I wanted the routing matrix however - that’s what ultimately lead me to build the MB-6582. 

I don’t really use 6581’s, so I haven’t experienced the sound leakage thing. I’ve read that others have dealt with it by using a noise gate in their DAW.

-Darrell

 

 

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9 hours ago, dwestbury said:

 

Yes, the button layout on the MB-6582 and sammichSID are different, but the main functions you’ll generally need are still accessible on the condensed sammichSID interface. The main difference is really the smaller screen and the missing routing matrix. The interface was really only designed for two rows anyway. The extra rows show secondary info, like scroll bars and progress indicators etc. I realized that I wanted the routing matrix however - that’s what ultimately lead me to build the MB-6582. 

I don’t really use 6581’s, so I haven’t experienced the sound leakage thing. I’ve read that others have dealt with it by using a noise gate in their DAW.

-Darrell

 

 

Thanks for the clarification. In the end being a DIY project, I understand everyone can make it as they like :) What is routing matrix adding to the overall experience? Maybe it is more for live usage? I am planning to tuck the device under the table or somewhere around and use it as sound module mainly, so the lack of extra controllers or even a screen is not bothering me (for now) :)

So the issue is just noise? The manual seems to mention ghosting, when a note is pressed and released; which to me sound like a pretty big problem. I can do filters; so if that is all is needed that should be simple; but I would assume there is a way to totally silence the VCO on the chip, to remove ghosting but I can't find much on the forum either. Maybe a fast program change back and forth would stop the VCO ghosting? Or send a reset signal? Although if I remember correctly, that will reset also the current settings you have on the buffer of the chip.

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3 hours ago, the_duckchild said:

Just been updating my website a bit with some words and pictures about various making projects... maybe this will be inspiration? I only really started soldering things in late 2016, so totally possible to do this thing

:)

 (you can teach an old dog new tricks it turns out)

http://www.robotriddims.com/makingmusing/2020/5/20/mb6582-midibox-sid-synth

Nice pictures! Those will come handy to get a comparison when soldering the components. Did you buy the kit including all the parts included? Would be nice to have an updated bill of parts for that kit, I just ordered the parts for the core and SID modules, not for the MB-6582 PCBs yet :)

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On 20.5.2020 at 6:56 AM, synthmania said:

Also as side note; using 6581, the manual warns about leakage of the sound after pressing a key; how bad is it? Is there a way to solve it? Because if I am recording audio that has leakage and background sound, I can't really do much to fix it (I can fix background noise with the audio tools available these days, but I don't think that will work for actual persistent audio that leak. I won't know until I actually build either solution so I want to be prepared about it

Use a noise gate effect plugin.

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Offtopic

On 21.5.2020 at 1:59 PM, the_duckchild said:

Just been updating my website a bit with some words and pictures about various making projects... maybe this will be inspiration? I only really started soldering things in late 2016, so totally possible to do this thing

:)

 (you can teach an old dog new tricks it turns out)

http://www.robotriddims.com/makingmusing/2020/5/20/mb6582-midibox-sid-synth

I bought the gameboy amp, too and wanted to built in but it is just for amplifying the speaker, not the phone output, right?

096BDF51-5CD8-4C4E-BAC5-4B245826C13B.jpeg

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On 5/21/2020 at 4:51 PM, synthmania said:

Nice pictures! Those will come handy to get a comparison when soldering the components. Did you buy the kit including all the parts included? Would be nice to have an updated bill of parts for that kit, I just ordered the parts for the core and SID modules, not for the MB-6582 PCBs yet :)

no, I just bought the PCBs from modular addict
I fortunately found someone who had a front panel left to sell. 
everything else was ordered based on this:

http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582_parts_list

although I had quite a lot of stuff around from other projects. It's a lot of parts though, I kept having to order things I had forgotten!

Re: The Gameboy, the pic you linked is a bivert board (to increase contrast on the backlit screen by flipping the pixel polarity)
You can get a replacement headphone amp for the old nintendo one (which is really noisy), but if you have a mixer it is just as easy to cut a hole in the case and put in a new headphone jack, and take the signal from before the headphone amp - the "prosound" mod. 
Makes the signal much clearer if you want to record it into a DAW or use it live. 

that's what I've done in this image:

IMG_20180203_171852_258.jpg?format=750w

 

(there are actually some even better earlier points to solder to that are before the volume wheel as well (that's quite often a bit crackly as well, plus it means you can turn the speaker down whilst still having the gameboy come out of the mixer.)

this is a bit off topic though  ;)


 

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Yeah, you're right, I did the bivert mod, too but mistaked this with the amp ; /

Thanks for the Info about the headphone mod. 

I've got a question left but will use open message instead the thread.

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