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The beginnings of a mbSID :)


unrise_lyrical
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Well, after reading on here for over a year and considering various projects, I've finally bitten the bullet and started making a mbSID synth :) all I have done so far is source a SID chip, purchase a 2x20 LCD and track down a box to squeaze it all into. Im going with a cigar box...dont know why...just thought it would look amusing :) Here is a pic with the LCD display in place after varnishing the box. I thought it would be an easy box to work with but I was horribly mistaken. Soft timber that marks too easilly, and is way too thick to cut through easilly...

digitalcigar.jpg

any comments/ideas? I am currently practising my electrical skills on a few simple kits before I take on this properly :)

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OK, first question. Will the following rotary encoders be able to be used on the mbSID?

Specifications:

Weight: 11g

Electrical Output: 2-bit gray code

Closed Circuit Resistance: 3 ohms

Contact Rating: 1 mA at 5 VDC

Insulation Resistance: 10 megohms at 250 VDC

Dielectric Withstanding Voltage

Sea Level: 50 VAC minimum

Electrical Travel: Continuous

Contact Bounce (15 RPM): 5.0 ms.

RPM (Operating): 100

Mechanical Angle: 360° continuous

Running Torque: 30.6 to 204 g-cm (0.42 to 2.83 oz.-in.)

Shaft Side Load (Static): 2.04 kgf (4.5 lbs.) minimum

Weight: 3 gm (0.1 oz.) max

Operating Temperature Range: -30 °C to +70 °C (-22 °F to +158 °F)

Storage Temperature Range: -40 °C to +85 °C (-40 °F to +185 °F)

Humidity: MIL-STD-202, Method 103B, Condition B

Vibration: 30 G

Contact Bounce: 10~55~10 Hz / 1 min. / Amplitude 1.5 mm

Shock: 100 G

Rotational Life: 30,000 cycles minimum

Switch Life: 20,000 cycles minimum

IP Rating: IP 40

Wave Soldering: Sn95.5/Ag2.8/Cu0.7 solder with no-clean flux: 260 °C max. for 3-5 seconds

Hand Soldering is NOT recommended

Power Rating (Resistive Load): 10 mA at 5 V DC

Switch Travel: 0.5 +0.4/-0.3 mm

Switch Actuation Force: 360 +153/-102 gf (5 +2.1/-1.4 oz.-in.)

Im aware of what kind of pots are needed for the MB64...but I couldn't see it written where it says what kind of encoders to use? Could their button function be used to trigger anything on the mbSID? or would it be useless?

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I thought the info on PPR, detents per rotation, driver support, links to forum writeups and other FAQs might be handy? Don't just stop at that one page of course :) A forum search for 'encoder support' turned out 9 pages of hits, but I don't really have time to read them all for you... Might be worth a look? I can't see any info on ucapps, but I only took a quick look....

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...but I couldn't see it written where it says what kind of encoders to use? Could their button function be used to trigger anything on the mbSID? or would it be useless?

you could use different types of encoders. and you could use their button. i'm still building my sid, too (will continue soon) and intend to make use of the button function in some encoders, too. but you'd have to decide in which case it is useful. for example the buttons i use underneath the LCD are still normal buttons while using some of the encoders in the osc, env, filter sections as buttons too. but try the forum search, there are some people who did it with different encoders, you can find pictures that show how they did it (for example look for Vinyljunkie's SID, i can remember this one because he uses the same encoders as i do and makes use of the buttons too.)

nice idea this cigar box!

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well, due to uni commitments I haven't had a chance to fully read up on the Encoder issue, but I managed to take a small step in the right direction :) Due to a bit of confusion with the other project im working on atm (building a strobe) I had a brand new stereo 6.5mm socket at my disposal, so I decided to use it for the mbSID :) I am no electronics wizz, but when I was buying it, it was a choice between this one, or a DPDT (dual pole dual throw) socket...does it matter this one isnt DPDT? to be honest, I can barely remember what that even means...

Anyways, on with the picture! Like I said...its not much but its a step in the right direction :)

aoutv.jpg

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The DPDT socket refers to a switching socket. The idea with these, is that when the jack is not inserted, it is "like they are not there", but inserting a jack breaks the internal connection, and instead routes the signal into the jack. They're needed for inputs (so that the switch connects the input to GND when no jack is inserted) but not for outputs.

Googling switching audio jack will probably get you some schematics etc for a more detailed explanation :)

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OK, first question. Will the following rotary encoders be able to be used on the mbSID?

Theoretically any encoder that outputs quadrature, or "2-bit Gray code", should work.  The real question is whether the selected encoder is desirable or not - for many reasons.  If it looks good, it probably is good ... but you might consider sharing a link to its datasheet.

They're needed for inputs (so that the switch connects the input to GND when no jack is inserted) but not for outputs.

To clarify:  you can use a switched jack for an output, but you won't need to use the extra terminals.  Switched jacks are also often used for headphone outputs, when the signal is perhaps normally routed to an internal amplified speaker, and plugging something into the jack breaks that connection so that you only hear it through the headphones.

Even the MB-6582 uses switched jacks on its outputs: when you don't plug something into an output jack, it gets passively mixed with the next output.

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well, I made another baby step today. Picked up some rubber feet for it on the way back from dropping in an assignment...Put them on excitedly before I realised it was rocking backwards and forwards :( I figured the box must be slightly warped...which isnt suprising as its made from such light material...but seeing as the feet are fixed with such strong adhesive, i just took to the "longest" ones with some sandpaper and it now sits flush :) Also picked up some stick-on PCB standoffs, as I dont want to be using screws through the soft timber. Will hopefully put in my order to smashTV sometime over the weekend once I have worked out exactly which bits I need.

Also, I stumbled acrosssome rotary encoders today on ebay. I have put up a post on another section of the forum about them but I figured I may as well ask in here. I have heard of people mentioning bourne encoders before, but can anyone tell me if these ones will work? Going by the "if they look good, they probably are" theory, Im guessing they will be pretty decent. They look a damnside better than the other ones I have seen on ebay.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=120413220840

The downside is they are $5AU each...which sure as hell isnt cheap...but as I am going for a minimal setup with the 5 assignable encoders...I think I only need 6 all up? (those 5 plus one for the menu?). If thats the case...I dont mind spending 30 bucks on them...if they are good quality.

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more baby steps made. I needed to fit some pine inside the container to help reenforce it and give something for the socket screws to bite into that hold down the top panel. This is proving to be a right pain in the ass as I had to cut one of these pine supports to fit around the audio output jack, only to realise after I had glued these piece into the box...the other one needs to be trimmed to clear the 2x20 LCD :( since it is glued in I will have to do this with a dremel I guess, which will be painful to say the least. Oh well, hopefully a bit of a sand and some more varnish and it will blend in :) I also ordered my CORE, DIN and SID kits today, along with a few other required parts :) oh, and some encoders...as far as I know I have everything other than a power supply and some buttons now :)

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I was wondering if anyone could give me some advice re. the front panel layout. As I think I mentioned somewhere in here, I am going for the minimal setup + the 5 assignable encoders. From what I have read, the minimal setup involves 9 buttons and 1 rotary encoder for the menu navigation. Here is the basic layout I was thinking of:

layoutdgo.jpg

Obviously the 9 red things are the buttons, the one rotary enc near the LCD is for menu navigation and the 5 rotary encs along the bottom are the assignable ones. Does this look like a decent layout? any advice on how to have the 9 menu buttons laid out better? Any help greatly appreciated :)

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Also, I stumbled acrosssome rotary encoders today on ebay. I have put up a post on another section of the forum about them but I figured I may as well ask in here. I have heard of people mentioning bourne encoders before, but can anyone tell me if these ones will work? Going by the "if they look good, they probably are" theory, Im guessing they will be pretty decent. They look a damnside better than the other ones I have seen on ebay.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=120413220840

The downside is they are $5AU each...which sure as hell isnt cheap...but as I am going for a minimal setup with the 5 assignable encoders...I think I only need 6 all up? (those 5 plus one for the menu?). If thats the case...I dont mind spending 30 bucks on them...if they are good quality.

I should sell Soundwell encoders on eBay... $5 AUD each is a really expensive.

Sorry I didn't read this sooner, I would have offered you some much cheaper.

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Encoders arrived today. I have already destroyed one pulling it apart but I figured I would probably kill one or two working out how to get in. There arent any actual things to bend back on these ones to get rid of the detents....its actually a spring-loaded ball bearing that bounces over the spline of a plastic cog inside. In typical ebay style...the company sent me knobs for it too...which are for a star-style shaft...and these are a d-shaft....so incredibly useful ??? oh well.

EDIT: Could someone possibly clarify if that is a good design for the layout of the front panel or not? :) Just want to check before I go hacking into it!

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well...me being as giddy (and impatient) as a schoolgirl, and looking for a distraction from my assignment thats due tomorrow...went ahead and just put the encoders in in the way I drew in the pic. Worked out better than I could have hoped for! The thread on them wasnt long enough to screw a nut onto...but they didnt come with any nuts anyway! BUT...the drillbit I used was just the right size that after i varnished the inside of the holes...they swelled up enough that I could just screw the encoders into the lid itself :) And after some selective grinding of that stupid little standoff tab thing on pots/encoders...they sit nice and flush! picture:

encoders.jpg

Heres the problem though. I have already broken two encoders trying to open them up to remove the detent. There are tiny tabs that sort of...split down the middle and spread out to form something like a snakes tongue....and they are about 1mm thick :/ I will take a photo when I have more time with a real camera...its too small for my camera phone to pick it up. Anyways...I have 2 more spare encoders (5 x assignable, 1 x menu one (finished), 2 x broken) but I don't really want to break any more of them :( Does anyone have any nifty inside tips on how to do it? I wish they were as simple as wrap around tabs that you can just fold back...but these ones are...well...f*cked up.

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haha, I never thought of timber knobs! I would love to use some if I could get them...Id even have a go at making some but fitting them to a D-shaft would be an absolute bitch :/

I've seen it done... What you do, is drill a round hole, and glue in a shiv to make the 'D'. (I've also seen cork used but that's another story)

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Well, I picked up some black aluminium knobs for it from Jaycar on Friday, only to take them back today to change them for straight brushed aluminium...suits the woodgrain more.

n789667276_1658323_4558300.jpg

Looking good so far!

...All the nice looking boxes lately make me really want to get mine completed soon.

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  • 4 weeks later...

I have been a little quiet due to university assignments and exams, as well as waiting on parts to arrive from smashTV. But they have finally arrived, and I have made them (there is another thread about that floating around). But here are a few more pics of where I am up to anyway :)

Holes drilled for midi cables....had to sand them to the right size by hand...took ages!

midicables.jpg

The finished components sitting in the box...fitting a power supply PCB in there as well is going to be bloody hard!

components.jpg

anyways, thats all for now! :)

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