Midibox SID all in one keyboard/synth

[pinksoir]

Hi there,

I am going to embark on my first midibox stereo SID. Of course first I'm going to get the core and sid modules and get it up and running, but I also want to plan ahead.

I'd like to build an all in one synth with midi keyboard integrated. The thing I can't really get my head around is how I would power the keyboard. I presume that because most midi keyboards can be powered from USB that they are low power consuming, but I'm not sure if I'd be able to power it from the C64 optimized power adapter or not, or if it would need it's own independent power source. Or if it was USB powered, whether there'd be some way to power it from usb in the box.

Something like this one by Reboot:

Hope someone can help.

Cheers,

Karl.

Edited October 7, 2011 by pinksoir

[orange_hand]

Hey Karl,

if you have already got a keyboard that you want to use for this, why don't you measure the voltage and the current ? You can then see how much current the keyboard draws and on which voltage it runs. I am pretty sure that you can easily integrate this with the replacement PSU....

Cheers

orange

[Hawkeye]

+1 / or you add a small powered usb hub to the optimized power adapter to power the usb keyboard (can be all hidden within the enclosure).

Greets!

Peter

[pinksoir]

Cheers guys

So I went and dug out the old keyboard. It's not usb powered but runs off a 9v adapter, 500mA. Or batteries.

I have no idea how I could modify the optimised PSU to run it though, but it certainly seems to be within the operating voltages...

I'm kind of thinking out loud, but would it be possible to run an effect off the power supply too? Sort of like daisy chaining. It would be cool to put a chorus effect in the synth, like a juno type BBD chorus or something. Possibly delay too.

Edited October 7, 2011 by pinksoir

[Hawkeye]

Well, in this case it might be appropriate to build a new PSU that powers everything...

E.g. one like this one:

Orange_hand is working on an improved PCB for this design.

It has more than enough power on the 9V AC line to power 9V AC driven fx units besides TKs optimized PSU circuit, or in conjunction with a second 7809, drive the keyboard or 9V DC driven fx units.

Greets,

Peter

[pinksoir]

Cheers Peter,

I'm not great at reading schematics and that PSU confuses me a bit... Perhaps in practice it's not too difficult though.

I think I'll forget about effects for now. What would I need to run just the midibox SID and the controller keyboard?

Karl.

[Hawkeye]

Hi Karl,

The optimized PSU circuit uses the 7809 for 9V DC and adds 5V DC (from the original C64 "brick PSU") to achieve 14V, which will be fed into the voltage regulators of your SID modules - which then convert this down to the operating voltage of your sids (9V or 12V depending on SID type).

You could just use another 7809 to create 9V DC from the 14V pins for your keyboard (copy this part of the circuit from a SID module).

Or, but I am a bit unsure about this, there could also be 9V available when measuring between the "blue" ground line, and pin 3 of the 7809 in the optimized PSU circuit.

In any case, i´d recommend you use a "real" 7809 in the optimized PSU circuit (not the low power variant), to be able to handle the additional 500mA load of your keyboard.

Greets and have fun!

Peter

Edited October 8, 2011 by Hawkeye

[pinksoir]

Ahaaaa... I see.

So copying the bottom part of this circuit onto a new veroboard (obviously with a 7809) will regulate it down to +9v. Should I run it from the 14V line after the sid modules?

Also, I see on the schematic that it says it's only 100mA. Is this a problem, or am I misunderstanding the schematic?

While I'm on the subject of power, what sort of cable and connectors should I be using to, for example, connect the 5V output of the optimized PSU to the core and SID modules? How do I split this cable? Or do I split it at all, but rather run two pieces of cable from the one connector?

I hope I'm making a little bit of sense.

Thanks so much for your help, Peter, I really appreciate it.

EDIT: I searched around and it's SIL sockets. How do I connect ribbon cable to them? I presume I solder them. But if I want to connect two wires to the one socket, eg. to connect the 5V line from the PSU to both the core and SID modules, what do I do? Is it possible to solder two wires to the one socket?

Sorry for my complete ignorance, I'm fairly new to circuitry etc having only built a few effects stompboxes. I'd like to have it clear in my head before I go ahead and start building, I guess.

EDIT 2: Ok, so it's actually on uCApps what to do. I directly solder the cables to the SIL headers. I presume I can use a SIL socket instead of soldering straight to the header...

Edited October 8, 2011 by pinksoir

[Hawkeye]

no problemo, to adapt a known saying... there are no irrelevant questions, only irrelevant answers :-)

a) Module interconnections/"power line"

I´d recommend IDC connectors, as available in SmashTVs shop: http://www.midibox-shop.com/buy.html

They are available with different numbers of pins for all your needs.

of course, you also need their counterparts on the veroboards, they look like this: http://www.reichelt....00&PROVID=2402

Regarding cabling/splitting the wires... for the IDC connector, you just insert a ribbon cable and press it together... a small tutorial can be found here:

Using these ribbon cables, you can also avoid "Y-Junctions", by just pressing on a connector in the middle of the cable and pressing on another one a bit away...

If you only have 2 pins for the power line, this is a bit overkill, but you could create a +14V, +5V, GROUND, GROUND, GROUND, GROUND power line using a 6-PIN IDC connector.

The good thing using these connectors is, that they are "coded", so a wrong connection is impossible. And you can separate your modules afterwards (reduces cable spaghetti a little bit :-))

b) where in the "power line"

it should not matter where you plug that mini-keyboard-"psu" veroboard... before or after the sid modules...

c) 100mA

...to my knowing are enough for a SID-.. That´s why a low-power 78L09 (or ..12 for the 6581 sid) in the mentioned schematics is enough to drive those. As you need 500mA for the keyboard, i´d recommend using two normal 7809s... one on the "optimized PSU" circuit side, and one on your "mini keyboard-psu" veroboard.

d) cutting the schematics

you need to start at C10 (330uf) and work your way rightwards (using a 7809 ofcourse)... then you will have a clean separate 9V out for the keyboard.

Please test appropriate voltages on all modules (SID, Core, Keyboard-Mini-PSU) before plugging in "active/expensive" components, like the keyboard, or any ICs (SIDs/PICs...)

Have fun!

Peter

Edited October 8, 2011 by Hawkeye

[Hawkeye]

Small addendum... TK. suggests "star wiring" for the power supply... to avoid ground loops/50hz hum...

Please forget the "powerline" concept and just solder the wires in "starlike" fashion directly to the optimized psu cirucit.

You could also achieve this starwiring using unpluggable connectors, split a ribbon cable (using e.g. a 10 pin idc connector at the "optimized psu" side) into three ribbon cables each carrying for example 5v/14v/gnd, which are connected at the optimized psu side.

The starlike connection ends in three connectors going into the unpluggable core module, the sid module and your keyboard-mini-psu module.

By the way, as you probably do not build the core/sid module on veroboard, you can also use lower-pin-count SIL connectors to achieve unpluggable connections at their end (which fit on the SIL headers provided by these modules).

Greets,

Peter

Edited October 8, 2011 by Hawkeye

[pinksoir]

Again, thank you so much Peter for your help.

I'm in Ireland, so I think I'm going to order the full kit with control surface from Mikes (I won't be building on vero). I guess that does mean I won't have the convenience of buying all the bits in one place (10 pin IDCs mainly).

I was leaning towards using SILs and soldering. But IDC connections seems better and more "idiot-proof". Which in my case is certainly a good thing! Also, from the looks of it, it looks like Mike's PCBs are laid out to take IDC connections. I just have to find somewhere that sells them... ebay is looking quite sparse unless I want them in lots of 100!

Are Y connections bad, or generally to be avoided?

Edited October 8, 2011 by pinksoir

[Hawkeye]

Ireland, so you could always ask Smithy for component sources :-)

No, y-connections are not bad (are even necessary when starwiring), just to some people "busses" may seem more elegant.

Greets and have a good time!

Peter

Edited October 8, 2011 by Hawkeye

[pinksoir]

So here is a mock up of the synth. I've added buttons for the arpeggiator. Is it easy or difficult to add that option to the hardware? I would certainly like to have an arp at my fingertips. I wonder if I've laid it out properly. Would there be a better button configuration? How about for the up/down 1 and 2 being the same button with two leds, and the same for down/up 1 and 2. Is this possible?

I also added a dedicated volume control too. I wonder why that's not on the usual CS, though I'm sure there is a reason.

I'm pretty sure that the complete CS layout has enough DINs free, especially since I've taken out the SID selection (I'll only have at most a stereo setup) and the Up and Down buttons that were near the Shift button. As it was there was about 15 places free on the 3rd DIN. I might need another DOUT though...

The octave buttons are from the midi keyboard.

What do you think?

Edited October 12, 2011 by pinksoir

[nebula]

Looks pretty cool!

I really like the look of those square buttons on the lower half of the panel. If it was me, I would probably try to figure out a way use more of the same square buttons in place of the tiny tact switches on the top half, just to tie the whole thing together. But I would keep the tiny buttons for the mod matrix.

That is, of course, assuming they are based on actual buttons you can buy!

Also, the bender is real cool, but do you have a lever like that? It looks like a JX-3P bender. It will be a hell of a challenge to incorporate into your own case design.

[orange_hand]

Hi,

I really like the design, that looks cool :-) !

Cheers

orange

[Imp]

Hey, nice one! Reminds me of a Juno somehow.

I wouldn't ommit the UP/Down-buttons though, i use those quite frequently.

The dedicated arp-controls would need some understanding of the code, AFAIK.

I just checked: Without dedicated controls, you can access the arp-menu with 3 actions (push button, turn encoder, push button) after startup.

If you set the row of encoders in the envelope section to "assign", you can directly control the parameters of the current menu.

Unfortunately, if you touch any other control(e.g. LFO-rate), it jumps to that menu. You'd have to navigate back to the arp-menu then.

[pinksoir]

Thanks guys.

Everything on it is based on available hardware etc. Here are the tact buttons if anyone is interested.In fact, the only thing I can't find a source for is a 2x20 LCD in black and red negative. Plenty of 2x16s though. I did find a 2x20 in black and white negative though. It dos look pretty cool with a 2x20 blue backlight if all else fails.

nubula, I originally tried placing the square 12x12 buttons on the top half but it sort of looks better without. There are coloured tact button covers avilable like these that you can see on the design above. It's by no means a finalised design so I'll be most likely messing around a bit more with the layout.

I do have that bender too. It's from the Roland midi keyboard I canabalized! It can be pushed up for modulation as well.

Imp, cheers for the info. I might stick the up/down buttons back in so. I wasn't sure if they were that useful as the CS page on UcApps says that they were just there as there were pins free. No harm in having them if they serve a purpose.

I'd really like to have a dedicated arpeggiator section as I reckon it'd be one of the features of the SID I'd use it a lot, especially on the fly live. I'm not too great with coding, but I'm sure with a little help from the (great!)community I could work it out.

The design is inspired from part Yamaha SK-20, part Prophet 600, part Jupiter 6 and part Juno 106, so you got one of the reference points!

[Janis1279]

So here is a mock up of the synth. I've added buttons for the arpeggiator. Is it easy or difficult to add that option to the hardware? I would certainly like to have an arp at my fingertips. I wonder if I've laid it out properly.

Hi,

Looks cool design!

The setup_6581.asm and setup_8580.asm files have entries for Arp ON/OFF function already. Only you need to enter the right SR# and Pin# for your own setup and to make the new *.hex file.

;; new for MBSID V2 (additional ***optional*** buttons)

;; don't worry, you still have full access to all functions w/o these buttons!

;; note that you could also re-arrange the pin assignments if required (e.g. if you don't like a certain button function)

DIN_ENTRY CS_MENU_BUTTON_M_Vol, 9, 5 ; matrix: button below M_Filter

DIN_ENTRY CS_MENU_BUTTON_Play, 9, 6 ; direct access to play function

DIN_ENTRY CS_MENU_BUTTON_SID_LR, 9, 7 ; direct access to L/R toggling

DIN_ENTRY CS_MENU_BUTTON_M_Mode, 10, 0 ; direct access to meter on/off function

DIN_ENTRY CS_MENU_BUTTON_Fil_ExtIn, 10, 1 ; direct access to Filter ExtIn Flag

DIN_ENTRY CS_MENU_BUTTON_Sync, 10, 2 ; jumps to ENS->CLK menu

DIN_ENTRY CS_MENU_BUTTON_Arp, 0, 0 ; enables/disables the arpeggiator of *all* oscillators

DIN_ENTRY CS_MENU_BUTTON_Knob, 0, 0 ; changes to knob menu

I did not find entry for the Arp ON/OFF led.

I have an interest to add the Arp led for my design, too.

Regards,

Janis

[pinksoir]

Thanks Janis. That at least brings me one step closer!

How difficult is it to code for new button configurations? The more I think about it, the more I'd really like to have dedicated arp buttons. I've seen a few Midibox SIDs with different layouts so it must be doable I suppose...

[Janis1279]

Hi,

It is not difficult to add in this code string

DIN_ENTRY CS_MENU_BUTTON_Arp, 0, 0 ; enables/disables the arpeggiator of *all* oscillators

the right SR# and Pin# instead of ,0,0 .

The each button , encoder has own physical place in a shift register chain and it are need to be documented in the setup file.

after your changes are saved the next step is:

http://www.midibox.o...hain_quickstart

Regards,

Janis

Edited October 15, 2011 by Janis1279

[pinksoir]

Thanks, those links are pretty useful, though it'll take me a few reads to get my head around them... I'm completely ignorant of coding!

Is it possible to add other buttons and encoders to control the arpeggiator on the control surface, like in my mock up CS I posted?

[Janis1279]

Hi,

I do not know many things, sorry.

I did some more reading for myself, too:

especialy #4

There are the some parameters for Arp controling in the Parameter Chart of MIDIbox SID V2 .

Thorsten can give the best advice for you, I think.

Regards,

Janis

[pinksoir]

Ok, thanks janis. I'll start a new thread to find out.