My MIDIbox SEQ... 100% sorted & finished

MIDIbox SEQ
1

Well.. this is where the projects at; Got one LCD to fix (and some logo decals to add on the case outers) ..then its done with :slight_smile:

After abit of soldering.. all the leds, functional & brought to the same brightness levels..

This is the original panel design for my midi box seq…

© Artesia 2005 :wink:

My less than tidy wiring & somedetails of internal construction.. given that it doesnt see much light of day.. i dont try to hard here:

Yup.. made with recycled pentum spec pc cases..

Drying front panel ‘decals’:

the lines on the panel dont really go like that :wink: its some funky interference pattern from image sizing…

Bare chassis.. front panel to be added on top..

Well.. some progress has been made with further construction; waiting on the nice people at lazertran to post on some of the inkjet compatable stuff (works in lasers too). This is the sub chassis which all the components & boards mount to; the front panel with all the (nice) graphics design will sit above this to provide a tidy finish… also the case shell will completely enclose this element.. keeping all the clutter & fixings on this inner shell element :slight_smile:

* upper row of grey buttons are diy ..Change of design from the render.. …made by flattening the top of some plain grey buttons with a file, drilling a hole in the middle & gluing some reclaimed speckled plastic to the top …results in a translucent button with a ‘sweet spot’ in the middle.. looks fun - will wire up for effect sometime soon…

(Should i put the following here ? ..hmm, ah well here it goes anyways..)

Progress has been slow here in getting these boxes built and finished ..as other little projects have cropped up and completed.

Of late i was lucky enough to get an abandoned, trashed  Leak Stereo 20 Valve amplifier & matching 2030 speakers from the 1960’s.

The speakers, although a dosmestic model …where based on the same 3 way technology; with a aluminum 10mm foam sandwich 10" woofer - used in their popular studio bound, sleeker.. bigger sister speakers.

Took some work to restore this lot… The speakers needed the rear spiders reattaching to the magnet & carefully centering up… but worked fine afterwards …damp got to the spiders over the years i guess. The amplifer needed a full overhaul, the chassis was repainted a curious pearlescent purple/blue ..which changes colour and tint depending on lighting (difficult to photograph !); As for components… all the capacitors were replaced & the resistors with modern high voltage metal film resistors.. DONT use ‘new old stock’ caps & Resistors …they are inferior & have usually deteriated to a worse state than that of the ones already present. Oh.. and new valves were needed… four ‘new unused, old stock’  Mullard EL84’s from ebay on the output end & three ECC83 Electro Harmonix’s on the in stage. …and the finishing touches were decent quality gold contact speaker & line terminals + a mains switch & a new solid base under the amp.

If you happen across one of these… or any other half decent valve amp… RESTORE IT ! …you’ll not regret it & even if you dont like em’ …theres plenty of people out there who will pay top dollar for a tidy one…

Iv’e always wondered what the fuss was all about with valve amps… and well ..the first time i rigged this one up …er Woa ! ..they do indeed sound nice :wink: ..very clean (and with modern caps+ res’s) 'n quiet… + the top end is clear.. but not harsh…

The 14-16w or so per a channel really does go alot further for some reason ..they can give a 50wpc amp a run for its money. At that, they really do sound shed loads better than most half grand transistor amps… had this up against a decent studio grade amp… and the Leak was far nicer to listen to :wink:

Quick note …there are afew el84 based designs out there on the web; if anyone wants to have a crack at building one from scratch …go ahead …just keep in mind that going above these power ratings with valves is generally un nessursary & it gets far more difficult to keep em sounding clean without buying silly expensive transformers ..and so on :wink:

A quick, and marginally blurry shot of the end result…

Sort of what the amp used to look like …except my one was scratched up & dented like crazy… Eew, that muddy gold colour !

A Hi-Fi world article about the Leak Line of valve amps:

http://www.hi-fiworld.co.uk/hfw/oldeworldehtml/leakstereo20.html

A Leak Stereo 20 restoration website ..proved useful to me…:

http://www.geocities.com/stereo20/

About the Leak sandwich speaker technology…:

http://werple.net.au/~kiewavly/sandwich.html

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Hey Artesia,

Nice SEQ design and nice valve amp!

Glad to see that there are still some tube enthusiasts left here in the full digital MIDI world ;D

I’m restoring a tube amp for a classic hammond organ at the moment.

It’s a M-100 and looks like on theese pictures: http://theatreorgans.com/hammond/dutchhammondsite/m100.htm

(Not my site and not the same amp I’m restoring! But it is as filthy as the one on these pictures.)

One of the high voltage capacitors had a short and so the transformer and some resistors ended up in smoke. While waiting for the new transformer I’ll replace the caps and clean the housing.

This amp has a very interresting design with a tube rectifier and some special circuitry for the “percussion” feature of the organ.

Tube amps rock!

Raphael

P.S.: For all the people who have no experience with tube amps: Be careful with the high voltages inside the amp. Some operate at 800V! And the caps will hold these voltages for a long time after swithing the amp off.

3

Update:

Got it oscillating, had fun working out where to go from the ‘infamous’ “F0 00 00 7E 40 00 01 F7” sysex message onwards.. Go there in the end…

there really needs to be a clear overview as to whats going on with the programming process for people who arent too familiar with pic programming.. As three things need burning to the pic to get it to work.. two by sysex… very disorientating first time round ..and if you forget about the mios layer that sits between the bootstrap & the app (doh !) …its a recipe for a good few hourse of goosed’ness…

Maybe a nice ‘layer’ diagram in the mios firmware download page; explaining how the app sits ontop of mios & the boot strap. ..with the configurable elements of each pointed out along the way… 

hmmm… damn ! …know why the second screen was not working now …its broke ! :frowning: …oh well time to wait on some more parts.. 

…back to trawling the forum & prodding the innards for the min…

4

hey Artesia, that design looks awesome.

One question though: Won’t the handles get in the way when operating the sequencer?

5

Thanks :slight_smile:

Not particularly… I did wonder though…

the knobs are easily manipulateable with just a forefinger, thumb or both.

the intention was to allow the device to be held by the handles and all the controls be accessable at the same time; without letting go …then again my hands do span 1 1/2 octaves ..so this may not apply for everyone..

6

Hi Artesia,

thats a great panel design, I’m just only missing your midibox.org logo in the middle :wink:

Yesterday I updated the bootstrap loader page, hope it’s better understandable now: http://www.ucapps.de/mios_bootstrap.html

Best Regards, Thorsten.

7

Thanks..

this is true :wink: ..i did wonder for a while if to include it on the front panel… and decided not to in the end; after much head sctratching as to where it would go comfortably… also i wondered if someone would comment about this matter :wink:

To be honest; there was another logo i would prefer to use; if one does go on the case somewhere.. unfortunately it looks like i may not adopt this particular logo, for this purpose… This might throw up alot of questions & dilemmas.. but nevermind.. :slight_smile:

busy soldering the hundreds of wires to the sub modules right now… and trying to get another display or two on order …lights on and a functioning box picture soon…

8

Another adveancement, another new problem here…

Got the led out section working great; however on wiring in the digital in board/s… only the first chip on the first board seems to be receiving signals correctly ..works fine with main control dial. however when the second chip exit button is triggered, it just seems to send random buttton signals and sends the midibox crazy (cycles through loads of the menus). cihps further on do not seem to trigger.

Each of the chips has a power line cap added …anyone have any idea what might cause this freekery ?

Would probably be better able to figure this if my oscilliscope was still working :frowning: (new one soon)

Something to do with the way each chip is chained to the next i guess..

…btw a nice bootup feature to see added to the apps; is a little routine which lights up all of the (registered) led outputs on startup. This immediately points out everything which aok ..useful during building; but also handy for determining during in normal use ..if the absence of an expected light is defineately not a hardware issue.

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…btw a nice bootup feature to see added to the apps; is a little routine which lights up all of the (registered) led outputs on startup. This immediately points out everything which aok ..useful during building; but also handy for determining during in normal use ..if the absence of an expected light is defineately not a hardware issue.

Thats not true, it wouldn’t simplify the debugging on some special error cases.

But thanks to the flexible MIOS concept, propably more is possible than you already know?

E.g., you can set/clear individual DOUTs from MIOS Studio debug window

Or you could just upload the very comfortable debugging application “dout_enc_v1_3”, which allows you to lit single LEDs by turning the MBSEQ datawheel

If not stuffed yet, you could also upload MIDI128 and control the LEDs from a MIDI keyboard, or from a virtual keyboard

Best Regards, Thorsten.

10

Leds are working ok; you have a point there ..was just a thought :slight_smile:

Back to the DIN section… have tested all the switch connections & the fault seems to occur somewhere in the serial linking chain between the ics.. thing is cant for the life of me; think why this could occur with everything seeming ok..

darn.. really need the scope to hand.. :confused: :slight_smile:

will try the “ain64_din128_dout128_v1_3.zip”.. although i already know what is not working… however it is a ‘why’ issue… :slight_smile:

ta..

…well checked with the “ain64_din128_dout128_v1_3.zip” ..it gets weirder :] ..for some reason every pic thats tested is receiving continuious ‘AIN’ signals …even though a ‘AIN’ module is not connected & the metal mounting plate is earthed ..latching down the inputs for that module  & disconnecting the remaining ‘din’ modules …does not stop this either :confused:

okay… all the pics are doing this… in all the cpu boards.. hmm..

..a little puzzled here…

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ok.. sorted now.. AIN latched down properly & DIN trouble shooting has been seen through with much tedious tinkering…

12

amazing seq box !!!

congrats

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ooooooooouuuuuuuweeeeeeee!  8)

I like that design! The invert LCD is giving everything the special touch! Everything fits together perfectly! Much respect for that baby!  ;D ;D

*applaud*

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Thanks :slight_smile:

Hey, Pay_c

you’ve come up with some really nice designs there too :slight_smile:

Thanks to your post, i’ve just been reminded of the neat trick you used to ring illuminate small push buttons on your midiboxseq. Given that im a complete sucker for illuminating every button possible (partly for easy visability in the dark); i will have to borrow that idea for my up and coming interface designs for the mbfm & mbsid :slight_smile:

Incidentally i have already designed them around the microswitch buttons.

I think i may have been inspired by your transparent mblc buttons when i ‘modded’ the custom larger buttons on this very seq :slight_smile: Btw what -exact- tool did you use to cut out the perspex circles ?

Hopefully tommorow when i get back, the next lcd display order will have arrived & i can submit the final write-up on this little project to the forum :slight_smile:

Have been working on the designs & panel designs for the mbfm & mbsid; all are designed to sit next to eachother in one aluminum suitcase… and for the challenge (+ studio space), have been minaturised as much as possible without comprimising ergonomics.

The mbfm was fairly streight forward to re arrange; however the mbsid panel has proven to be -extremely- difficult to re-organise… My hat goes off to anyone who comes up with a custom re-design that they are 100% happy with :slight_smile:

15

i’ve just been reminded of the neat trick you used to ring illuminate small push buttons on your midiboxseq.

Was that the post about drilling a small hold with a ‘hole saw’ bit into a piece of plexiglass and inserting an LED into it, or is there another method I’m missing?

Thanks!

-drin

16

Yupp, right. Holesaw.

I used a 16mm holesaw (inner diameter = the diameter of the cut out piece = appr. 12 mm) and a 19mm holesaw (the same = 15 mm appr.). Without the center driller the pieces are cut out at a *STAND* driller (fixed in every way). The drilling speed should be well above normal (the double amount is ok) and you should no press to hard. This way you won´t get to much thermal stuff and so nicer buttons. It´s a bit tricky at first but somehow you get to it.

After that a small hole into the middle of the piece (tricky again here) for better and more stable glueing and that´s it. Putting/glueing it onto a normal button and backlight it! :slight_smile:

Greetz!

17

thats cool :slight_smile:

My method of making the custom larger buttons seen here consisted of takling the generic standard grey MEC buttons (got a ton of them for pennys at a radio show).

drilling a 5mm hole in the middle with a drillstand, then filing the top flat & gluing on a slither of frosted perspex recovered from some of those frosted blank cds found in spindles of cds.

Then the button is pushed onto the head of a suitable sized bolt fixing & loaded into the drill as a drill bit would be. Then the keycap is spun in the drill against a coarse file & afew grades of sandpaper to grind it down to a perfectly rounded & smooth finish :slight_smile:

Will try the hole saw method too; though iv’e not seen many smaller than about 3/4 inch…

18

hi drin,

im on about various methods of making round keycaps as in the above posts :slight_smile:

I also mentioned about placing a ring of plastic around mini buttons as pay_c has done with his mbseq. as he says; this was done by cutting a length of clear flexable plastic tubing & pushing/gluing it onto the shaft of a microswitch.

19

On the note of transparent tube lighting around switches…

have now equipped all the switch elements for the mbsid & mbseq with a slither of tube & led.

The most effective away of illuminating the ring (for me) is pictured as below..

Putting the led on an angle betwen 90-45 degrees to the shaft of the switch proved most effective for optical coupling. By trimming a small section off the plastic at the base, the ammount of light that works its way to the top tripples.

I found that the finish of a clean knife cut provided on the exit end was sufficient for good illumination… sanding or filing the end just resulted in a inconsistent appearence.

(the shift in brightness on one side is no where near as obvious as here - also by cutting more smoothly & closer to the base; this can be avoided)

Btw, normal cynoacrylate superglue is useless for attaching the tube to the switch shaft.. it just works its way into the switch and jams it ..no matter what you do. also hot glue gun glue (although bloody excellent stuff for projectwork allround)  ..is useless at adhering the two plastic types …will try some abrasion & a tiny dab of araldite to prevent the tube slipping on the shaft over time.

…also for some fun …ever wondered what 77 (12-15mcd) Leds pushing out a rough total of (1.2cd) 1,200 mcd for 5 watts in looks like ?

Makes a pretty good chill out room light :slight_smile:

…and WHAM !

:slight_smile:

…has no problem lighting up the back garden either. …Though id probably advise getting some luxeon lumileds instead. For three reasons.. A: they come in 1-5 watt sizes for one 5mm size chip B: it’s a hell of alot less soldering C: it’s usually cheaper. I had 3,000 of these from a ham radio show a while back for an unbeleiveably cheap price :slight_smile:

Further notes on luxeon lumileds ..for the same 5w that the above array consumes; a single 5w lumiled produces 100x ! the output at (120cd) 120,000mcd. (even the 1w one produces 45cd).

Be warned those really are quite hazardous to stare into ..talk about condensed light - even the above array is quite painful…

see: http://www.luxeon.com

20

These buttons look cool, where do you get the plastic tube?