FM262 First DIY Project

[minya]

Hello guys,

i'm very proud having my first DIY Synth just started! I decided to build a SID Synth with as much SID's as possible and also a YMF262 FM Synth. When i tried to desolder the yac chips i was overtly too rough and broke some pins. But fortunatelly i had found another soundcard on ebay, bought it and now the YMF scheme is ready soldered.

I thought about doing the same 19" version as shown on the ucapps site, but i came to the conclusion, that my 19" Cabinet is already full enough and a desktop version would also be very beautiful. So i just drafted an idea i had last night. I want to build the FM Synth in a white coloured frontpanel and some wooden parts on the side....

here is a small draft of my idea... these days i'll take my order from the tax office and build the rest of the schmes which were needed

ps: sry for bad english skills :D

ppps: the draft is build with the original version jpgs of TK and just arranged in another way

peace,

markus

[TK.]

Nice "Blofeld" format! :)

Best Regards, Thorsten.

[stryd_one]

HEhehe totally Waldorfian :) Look forward to seeing this thread grow!

[minya]

hellau,

all modules are ready soldered, dinx doutx, core and ymf module are done. Today i wanted to buy an transformer, but i read in the forum that it is possible to use the c64 one. i have one laing around and so i decided to use this. can anyvbody tell me if i need some accomodations or can i use it directly? has somebody maybe a scheme about the c64 transformer pinning?

thanks and regards,

markus

[stryd_one]

I believe that someone has been working on a schematic for using the MBSID Optimised PSU with the MBFM but it might be a little while before they can talk about it... But it has been described before. You do need to add some circuitry to make it work.

[Foona]

I love the look of that layout you've done Minya!

[minya]

@foona: hey thank you very much! i love to hearing that ...

i already downloaded the scheffer software to but i did not jet found an option to make white panels there, just black ones. but at the website they also offer white one ... i'll phone them tomrrow and ask if that would be possible

@strydeone:

yesterday night i watched the psu options which were provided at the wiki and i'm not sure if i shall take one of these, the c64 one, a already build +-12v one ... or however. Do you know if they all work fine or if there are some problems with the fm and one of these psu systems?

i thought about method 3 "3. Then there are two excamples of how to connect two identical 12v power adaptors. It is very important to use two identical ones! Same brand, same rating, best bought in the same shop the same day! You get these in regulated and unregulated versions."

might i do this with this transformator http://www.reichelt.de/?;ACTION=3;LA=4;GROUP=C525;GROUPID=3316;ARTICLE=27370;START=0;SORT=artnr;OFFSET=16;SID=27d-jEZawQARsAAHTfbLcdc8d159c31b1d24dda8b52285bcd8c75 and scheme 3 for the 12+-v psu and which one can i use for the 5v voltage?  ???

thank's

markus

[stryd_one]

Well, the C64 optimised psu is not bipolar so it requires some modification... Using two EXACT same PSU's should work, and has for some people, but it's also caused trouble for others. Just my own personal opinion, I would not go that way.

If I was you right now, I would be waiting for that person (who shall remain nameless until they announce this themselves) to return with a known and working solution, or I would look at NorthernLightX 's very big informative PSU thread... You linked to a +/-12V transformer, personally I'd go for the +/-15V and use circuit #1 from the wiki page - which in case anyone's wondering, is this one: http://www.midibox.org/dokuwiki/bipolar_12v_psu. Quite a few of us have recently bought  transformers from pollin.de: cheap transformer for bipolar PSUs at pollin.de Which look perfect for a power supply that would be bang-on for an FM, and various other projects too :)

Hope that helps!

[minya]

hi strydeone,

thanks for your fast reply! yes i think it heps a lot and i'll try to buid the same one if you think that works fine for the fm. another question, what is exactly meant with the double size of caps? aren't they just 100n and 10u ones?

the ground conections in the middle are also connected aren't they? i already ave the 78xx and 79xx here, i can't build them in the circuit on the wrond direction? and one last thing ... is the thing on the left side a diode and which one shall i use?

i'm sry but i'm not really experienced in electronical circuit but nevertheless i want to build it save and working fine. cnan i also use the mk528 with circuit scheme one ... in the wiki they tell something about 15+-v and this one is 13,6v is there any mdification needed with the 4,2v output or can i use that directly?

thanks for your patience :D

markus

[Foona]

hi strydeone,

thanks for your fast reply! yes i think it heps a lot and i'll try to buid the same one if you think that works fine for the fm. another question, what is exactly meant with the double size of caps? aren't they just 100n and 10u ones?

the ground conections in the middle are also connected aren't they? i already ave the 78xx and 79xx here, i can't build them in the circuit on the wrond direction? and one last thing ... is the thing on the left side a diode and which one shall i use?

i'm sry but i'm not really experienced in electronical circuit but nevertheless i want to build it save and working fine. cnan i also use the mk528 with circuit scheme one ... in the wiki they tell something about 15+-v and this one is 13,6v is there any mdification needed with the 4,2v output or can i use that directly?

thanks for your patience :D

markus

I wouldn't worry about patience here.

If this forum has an abudance of anything, it's patience...and information. ;D

When i started in the DIY electronics buissness, i hardly knew anything myself.

But by the help of google, forums like this one and patience ;) iv'e learned alot.

So im gonna try to answer your questions.

Thing on the left:

The thing on the left is a bridge rectifier.

You can either use a rectifier or regular 1n4001, 1n4002, etc.. diodes. With diodes you need 4 of them.

It will look like this:

(i borowed this part from the C64 optimized circuitry for the SIDv2)

Reguator pinning:

Be shure to check the pinouts of the regulators.

Do a search on them, and im shure you'll find datasheets on them too ;)

<add-edit> aw hell... here you go:

Regulator Pinouts

BUT! Do not assume that this pinout is the right one.

Be shure to check the datasheets for the regulators you have.

I'll borrow a quote from a Steven Seagal movie.

"assumption is the mother of all fuckups"

Regarding ground:

If you look closely at the schematic from the wiki above that iv'e linked to,

you can see two AC outputs from transformer going to oposite sides of the rectifier (the diod looking thingy).

And the middle one is 0 volts (GND=ground).

I know that reading schematics can be hard when being a n00b,

and i always try to find graphical info, wich makes it easier to grasp.

So i made this for you:

Hopefully i did it the right way (in any other case im shure im gonna get slapped by somone),

and hopefully you will see the answers right away. :)

Double sized caps?

Im not shure about what you mean with double sized caps,

but be shure to make shure youv'e got the right types.

If you look at the schematic, 100n looks to be ceramic, other sorts can be used,

but i bet this schematic is based on ceramic ones. You do not have to take polarity in count with these.

The 10u ones is electrolytic caps. These have polarity.

The thick line on these (looking at the schematics) are - and the thin lines are +.

eh...do i make sense?

Be shure about all this before you do anything!

As the wiki say, polarised caps can blow up if mounted in the wrong direction.

Anyone noticing errors in what iv'e stated here may slap me!   ;D

oh yeah, regarding the mk528, i have no idea what this is.

But you've peaked my interest, so i'll check it out.

Hopefully somone else here on the forum might answer you before im able to.

<correction-edit>

After being slaped by bugfight iv'e changed the statement

about using 1N4148 diodes for rectifying, to 1n4001, 1n4002 power diodes.

Thanx bugfight!

[minya]

hey loona,

thanks for your reply! i also read a few things and the 78xx and 79xx pinning should be clear now, thanks again! i found a cheap tranformer at reichelt and bought this, it's just a single one, but as i understood the threats i read it shoukld also work fine with scheme 2 ...

i bought

WIPPE 1832.3312  Wippschalter, 2-polig AUS, 20(4)A/250    1          1,95 Euro

FLINK 0,63A      Feinsicherung 5x20mm, flink 0,63A        4          1,16 Euro

SB 140          SCHOTTKY-DIODE 1A/40V                    4          0,53 Euro

FLINK 0,5A      Feinsicherung 5x20mm, flink 0,5A          2          0,58 Euro

TEKO 364        ABS-Kunststoffgehäuse 311x170x87mm        1          15,50 Euro

MKS-2-5 100N    WIMA Folienkondensator, Rm 5mm, 100nF    6          0,74 Euro

RAD 10/35        Elektrolytkondensator, 5x11mm, RM 2,0    10          0,41 Euro

EI 48/16,8 115  Trafo 10VA, 15V, 666mA                    1          4,10 Euro

LEITPASTE 10GR  Wärmeleitpaste, Metalloxydpulver, 10g    1          1,70 Euro

BSN 4.700/40    Snap-in Becher-Elko, 25x40mm, 4.700F/    2          5,40 Euro

PL 112000        Sicherungshalter, 5x20mm, max. 6,3A-2    4          0,49 Euro

SM 10/16RAD      Subminiatur-Elko, radial, 10µF/16Volt    4          0,29 Euro

V CK960/20      Aufsteckkühlkörper für Gehäuse TO-220    2          3,40 Euro

KES 1            Kaltgeräte-Einbaustecker, waagerecht      1          0,30 Euro

EI 42/14,8 109  Trafo 5VA, 9V, 556mA                      1          3,30 Euro

FLINK 0,8A      Feinsicherung 5x20mm, flink 0,8A          2          0,58 Euro

i hope the 15v 666mA and 9v 556ma transformer is enough for this project. i already thought about the fuses, they are obviously too little for using. For scheme 2 it is told that the double caps size of the elkos should be used, i took 4.700F/40v hope thats ok, and i hope the diodes will also work

i haven't found a good and safety looking +- transformer, that's why i decided to try it with this

markus

[stryd_one]

Thanks Foona! I've had this reply on my to-do list, and now I get to take a break, thankyou :)

I'll give some quick answers and extra info... Pardon me for being brief, but my browser has crashed 3 times while typing this reply... after the third time, I feel somewhat less poetic ;)

what is exactly meant with the double size of caps? aren't they just 100n and 10u ones?

That refers to the caps labelled C, or in that diagram, 2xC. See section 4 in that document for the size of those caps, which should be doubled if you use the design you refer to.

the ground conections in the middle are also connected aren't they?

Yes (see foona's post)

i already ave the 78xx and 79xx here, i can't build them in the circuit on the wrond direction?

You can, and it won't work and may blow things up. Not highly recommended ;) Make sure you get the correct datasheet  (see foona's post)

is the thing on the left side a diode and which one shall i use?

well on the seft is the transformer... Diagram one shows a rectifier after that, which is a box with an arrow onit - that's your four diodes. The other symbols  which look like an arrow pointing at a wall are diodes. Essentially, they make the electricity only flow in one direction (electrons, ie negative charge, go in the direction of the arrow). This takes the AC current and makes it DC.

cnan i also use the mk528 with circuit scheme one ...

Yes it's recommended. I will :)

in the wiki they tell something about 15+-v and this one is 13,6v is there any mdification needed

Well, no, is the short answer... Long answer goes somewhere though...

in the wiki page it says:

The regulators need a voltage 3v higher than their output to work correctly.

That's kinda right. The voltage regulators need an input which is 2V greater than their output**. This is because the electronics in there need power. Also, the diodes tend to cause a bit of 'friction' (all those electrons smacking that wall) and that means that they drop about 1V also. So, in total, you should aim for around 3V greater input, than output.

So, to get 12V out after the rectifiers and regulators, you really want 15V to be out put by the transformer.

Also take note of:

Many small printtransformers will give more than their rated voltage when little current is drawn.

The audio circuitry does not use a lot of power, mostly because there are no big flashy lights or heat or moving ports, which all eat lots of power. The quote from the wiki I pasted there is a hint, that perhaps your transformer may actually output a little more than what it is rated to. So ,maybe our 13.6V will actually output as much as 14V or so

** Coming back to the regulators - if your circuit does not draw too much current, then the regulator may need as little as 1.5V greater input than output. This, combined with the above, means we may only need about 14.5V input.

If you've done your math ;) You already noticed that we are short by about 0.5V.... So in theory, the pollin transformers should not work.... However nILS put his $$ on the line and tested them, and sure enough he has assured us that they work a treat. Which just goes to show what theory is good for ;)

with the 4,2v output or can i use that directly?

You won't use that at all. Using the above theory, the +8V output of the transformer is meant for a regulated 5V circuit, and the 4.2V is meant for a 3.3V circuit. We don't use any 3.3V componentry, so you can leave that one disconnected :)

[stryd_one]

it's just a single one, but as i understood the threats i read it shoukld also work fine with scheme 2 ...

I don't know if anyone's actually tried it yet, so please inform us of your progress :)

i hope the 15v 666mA and 9v 556ma transformer is enough for this project.

15V@666mA definitely, that's lots.

9V@556mA...uhm... Maybe. I hope you don't have lots of LEDs or a hungry backlight on your LCD.

For scheme 2 it is told that the double caps size of the elkos should be used, i took 4.700F/40v hope thats ok, and i hope the diodes will also work

Ahh I see you've been doing your reading, nice one. Next time, tell me that you found the answer to the question you asked me, so I don't spend an hour typing something you already learned :D

i haven't found a good and safety looking +- transformer, that's why i decided to try it with this

Cool, good luck!

[baconjuice]

Nice post Foona! Seems you got this power supply thing down.  8)

[bugfight]

You can either use a rectifier or regular 1N4148's diodes. With diodes you need 4 of them.

It will look like this:

1n4148 is a small signal diode, you want power diodes (1n4001, 1n4002, etc)

Anyone noticing errors in what iv'e stated here may slap me!  Grin

*slap*

[MTE]

The "OPL3-PSU" works great,tested with scope....ignore the "MB-6582..."-schematic, Im still testing...

....enjoy ;)

[buhler]

*slap*

man foona!!! that's 2!!! i'm jealous! ;D

[Foona]

No need to thank me stryd_one. Im just trying to give back

what iv'e got from you guys.  :)

Baconjuice: I might have gotten this PSU thingy down (exept for the diodes..ehrm..),

but im faaar away from understanding how all the other curcuits work.

I guess i'll get those in time too.

Mr Bugfight, i think were gonna have to pull out some leather wips soon.. 8)

And Buuuuuhleeeer  ;D

SLAP!!!

I bet you liked that one huh..oh yeah!

[minya]

hey strype one

thanks again for your reply ... yes i did my homework and read a lot. please don't worry about ordering some caps, and i don't believe that your post was senseless, i read it very interested and talked tonight to an electrician, who told me that solution 1 would be the best. but i'll try it with the single transformer and tell you if it works. but nevertheless i'm verry glad aboutyour answer and am very sorry about making you the work!

peace,

markus

[buhler]

And Buuuuuhleeeer  ;D

SLAP!!!

I bet you liked that one huh..oh yeah!

WOO HOO!!  this is the greatest forum EVER!! ;D

[stryd_one]

Hey MTE, Question: why the low power 7912 with a full power 7812? I think you coud mix'n'match them for this circuit anyway, but...juts curious :) (learning)

WOO HOO!!  this is the greatest forum EVER!! ;D

Ain't it just?

[minya]

wahhhh those reichelts sent me the wrong caps so i have to buy nother one tomorrow, and i'm still thinking about the two transformer solution ... let's have a look what the conrad guys will offer!

is there any modification needed with the 9V transformator? have i got to build the same recruit thing as on the 12v one or can i use it directly? in the ics of thorsten  saw there were three 79xx / 78xx ...

thanks

[minya]

a few days later, the psu problem is solved ... those damned 7912's made me buying a complete one. now the core, the display, the psu and the fm module are connected and the first "ready" message appears, backlight doesn't jet work, i'll check te connections again

the first part of led and buttons are also ready but not jet connected.

i believe i have cooked the op amplifier tl074 when i put it inside in the wrog direction first time (the led glowed shortly and periodical). when i switched it the fm modul led glowed permanently and everything seemed fine. i tried to upload the mios fm testsongs and a lot of smoke can out after a short time. the tl074cn has a little black dirt on one of the middle pins i think the wrong direction action killed him. after reconnecting to power the led glow periodical again. when i took it out of the socket, the led glowed permantly and the display began to show mios start prg and gave the midi start commandso i guess it's gone, i ordered some new ones :D

here is a short clip of my works of today  ;D

attention, 10 mb for a short clip

http://www.jenshansky.de/minya/data/fm.avi

markus

[minya]

hey guya,

backlight of display is burning now, i got the wrong pinning. tomorrow hopefully the new tl074 will arrive and i hope everything will be fine than and no more smoke will appear  :o

my first frotplate is also done, two holes a not perfect so i have to make them bigger, but display and most of the leds and buttons are suitable. the two holes of the matrix buttons are not very exact

i have made a picture with display, leds, encoder, buttons in it

[minya]

yipey! so hopefully i can make my birthday present for saturday on my own :)

just the bank sticks, the new tl074 and the wiring between din, dout has to be done. The frontplate will be brushed this week and when i get everything in the case, that should work *hehe*

i also have to watch the fixing of the modules at the case. unfortunatelly the holes are not at the positions i need them. i thought about glue (i guess eseciatelly for the transformer thats no real good solution), a wooden plate where to screw all on (maybe it's also not the best possibility for the transformer if it gets warm) or another screwing solution with some fixing plates or line in the case where i can fix everything

i guess screwing will be the best and safest solution ... i'll keep you up to date!

1.) a short question to the bank stick ... can i take 4x265 and connect them as in the scheme A0-A3 and take another one for the ext. bankstick with A4 or have all 8 Ports to be connected with sticks?

2.) another question about the leds: i haven't seen the fm working complete and i'm not quite sure what usage the hole matrix has got. Would you mind taking all leds in the same color or do you recommend to use special colour leds for some functions. At the moment i thought about

- power led (right top) green or red

- every matrix led green

- the 4x1/2 select leds both green

- the instr/op leds red

peace,

markus