TheAncientOne

Thanks Jaicen, invoice received and sorted. Very good of you to help out like this. You are more efficient than my bank!

I think the HDD actuator idea is brilliant, though they do eat quite a bit of current. Later on, it might be possible to make a variable impact driver with these - so it might decode the MIDI volume, (though not that well)..... Anything to avoid coil winding! I think an old HDD is going to be dismantled next week. I've been recycling them, selling the alloy for scrap, and using the magnets for stage prop work. Put up a thin steel strip, and they are great for hanging drapes and background cloth. My first go used old relays, with a hammer stick glued to the actuator, they are quite noisy though, better when I put some felt on the top of the coil. I'll get busy with a 555 based design. I've been looking for a child's toy xylophone this week

Perhaps it's just me worrying too much: I do a lot of work with industrial control systems, and whenever we've had problems it's been something in the outside world of the machine upsetting the micro. I've got some very scary horror stories too: like the toolpost box on a CNC lathe that had a low voltage position sensing switch wired direct to an I/O card on a PDP11 computer, (old, well cool mini computer), and a mains operated positioner, nicely opto isolated from the control gear. Very good, until someone got a coolant leak. Then the liquid joined the sensor to the mains drive and put 240 Volts onto the DEC Q-Bus. Tough old birds those PDP11's, I only had to rebuild the IO card. More recently, a local company added a colour pellet doser to an injection moulder. we kept having what seemed like random control hangups, until I found that in installing it, they'd connected the doser direct to a spare IO, (as per the handbook), this let motor noise from the doser on to the controller ground, and was causing random triggering of other IO. A very basic opto cleared that. I may have got this wrong, but you seem to be thinking of driving the xylophone direct from a sequencer. The more I think about it, I would prefer to make another basic core, and do a MIDI to solenoid unit, like some of the organ guys, then a whole lot of things could be MIDI driven, (like my Christmas lights....) On the solenoid idea, I think I'll try it out. Here are my thoughts to get it going. 1) use a relatively high voltage for the solenoids, then you won't 'starve' the power supply if you 'fire' more than one at once. I was thinking of 24V. This also reduces the current, and there is less risk of damaging the ULN. ULN's will deliver 500mA from one output, but this drops proportionally as more are used at once, ending at 120mA if all are being used. This might not be enough for some solenoids. 2) get some decent, FAST spike killer diodes. Some ULN have then built in, but they may not handle the reverse kick from the large solenoid coil. 3) The 24V supply does not have to be regulated, just a reasonable amount of capacitance to feed the solenoids. 3) if the xylophone hasn't got too many bars, perhaps a 555 pulse stretcher might be the way to go for now, I can get 555's for £0.15, so each pulse stretcher might cost less than £0.50. There is the option of tuning the pulse lengths with a trimpot, which might help get a more even tone. This is messy, but the 555 will drive a cheap Darlington transistor or power MOSFET, and you wouldn't need the ULN's. If you went for a MIDI to Solenoid unit, then the pulse widths could be re-written in software. I really do need to take the usual advice and dig into the Wiki, because I think this has already been done. sorry for rambling

I'm thinking that whatever you do, it might well be worth opto isolating the gate outputs from the hammer drivers. Solenoids kick out a lot of spike, which could kill the micro. As an aside, with 3 fast opto's it would be possible to isolate a DOUT or AOUT, which I've been thinking about recently. Because of the high voltages in an analogue synth, (+/- 15 Volt supplies and 10V control signals) and the possibilityl of damaging the sequencer by bad patching.

Another point: the 12V supply is only stable by reference to the 5V. The 12 in a PC is for disc drive motors, fans etc. Not optimised for running audio. The soundcards usually have their own sub-regulators and lots of decoupling. A final thought. On some cheap PC supplies the 12V can 'glitch' on power up, hitting 20V or so, not good for the delicate audio stuff.

With solenoids you need to be thinking in millisecond terms - microseconds is way too short for most of them.

Sorry - forgot to post a further note. My packing supplier still hasn't got the larger bags I need. Should have them on Monday, and will weigh and invoice then. 2 packs of J B Weld left.

There are some very good notes on MIDI at http://www.hinton-instruments.co.uk/reference/midi/promidi/index.htm#pt1 One point he makes is that pro gear should use separate metal DIN sockets, with an indirect connect to the main circuit board, for ease of replacement in case of damage. I've used board mounted connectors on my "Wilbabeast", because it won't be going out on the road. I'll be using metal connectors on molex connected leads on my sequencer because it will. You can also loop the flying leads through a ferrite to reduce RFI.

I've just emailed the UK distributer from my company to enquire about costs and minimum order quantities. I use the splined knobs from rapid for my analogue synths, and really like the encoder knobs, which, sadly, Rapid don't do. Re-An do really good collet knobs, though more expensive, which means that you don't have to worry about pointer orientation. By the way, best simple panel design I've seen recently: http://www.ams-neve.com/html/models/Outboard/88__Series/8816/ But then again, I've never seen anything Neve that I didn't like. I'll keep chasing this one, because, having got them, I don't fancy the Albs Waldorfs on my sequencer, though they look fine on the "Wilbabeast". Using the Re-An's might give a better panel layout, especially with my fingers.

I've been playing with touch films for a while now - they use them in industrial controllers. Rather than use a whole screen, I had another idea recently. Put the film on a translucent backing, and fit it over a bigger modulation matrix for a MIDIbox SID CS. That way I would have the equivalent of one button for each LED on the modulation matrix. I just have this vision of a sort of 'Star Trek' all touch panel, eventually. Ther is a sort of half way option that uses a very basic screen driver to colour the spots on the matrix, perhaps to show what has been updated. Just a thought. The worst parts of coding seem to be the noise elimination and the 'quantisation' for the zones. I need to dig into my archive, I do have some code, (in FORTH), for, resistive, HP optical, and I think one which was accoustic. THe HP was the easiest, because the low level drivers were built in to the old HP150, and you could simply use it by escape commands to the terminal that was built in. As an aside, it also did Tektronix 4010 graphics too, by issuing the correct sequences from the keyboard, you could use one as an "Etch-a-Sketch". On the HP150 mk2, the touch screen was already an optional extra. I must dig out the system I kept and see if I can drag it back to life. Wow, the joys of DOS 3 on a green screen with a wonder HP-IB, (IEE 488), bus to connect the drives..... I have got the Microvitec 'Touch Tech' soemwher too, they were optical for BBC micros, and fitted onto the 'Cub' series of monitors. They're output was serial, showing that you don't need much speed for something like that. They had a on-board controller, which might be worth looking at. Again thewy were the 'grid of LED's and sensors' style. I suppose you've all seen the Lemur. http://www.jazzmutant.com/lemur_overview.php As you might have guessed, unusual control systems are a pet interest of mine - I did some work for a charity for the disabled years ago, and worked with breath/mouth controllers, lightweight joysticks, a few other things. Eye movement was still impractical then, though I believe working controllers are available now.

No it's a metal loaded epoxy designed for glueing metals. It's what Wilba recommends for fixing the screw heads to the panel back. Hope this helps

6 tubes of J B Weld on the way: 4 spoken for: Me Twin-X Nati Goblinz 2 more up for grabs at about £6. Will have twin packing on Thursday, so last invoices will be out then.

Got mine today. Thanks very much for organizing this Goblinz, I know just how much work goes into it! Best wishes

Got mine at the weekend. All LED's fit fine, panel looks good to me - I know I couldn't do anything as good, and the savings over Schaeffer, my only other realistic option, were amazing. I'm quite happy. Detail could be slightly better, I agree, but I'm happy with what I got for the price. Thanks Altitude for all your hard work. Best wishes

That's a bummer, hope you didn't lose anything really vital. I've cancelled the old invoice and sent a new one. Best wishes

Mine got in this morning - I wouldn't look that good after such a long flight - thanks for a wonderful job.

yeah! kind of like silent move meets video game.

@OpKod Yes - I've ended up with a couple of spares, due to something of mine not being a practical fit into one. Shall I invoice you? Your first one is on the way - and posting 2 together makes only a few cents difference to the price anyway.

Prof Packing department update I got all the '1 box' invoices out today and some speedy people who paid fast got their boxes in the post today as well: Sent as of 4pm 30/10/07 UK time Goblinz Sparx JulienVoirin OpKod ToF Multiple pack invoices not out yet:- different prices.

I'll save 12 Caps for you, Julien. I'll put them in with your box - will invoice for the box later today.

Standard on certain types of board, to insulate via's and provide a little bit of stand-off. As you can see, they're not exactly expnsive - unlike the mounting stand-offs for LED, which can cost more than the LED. Crystal pads at Rapid There is a whole range of this type of hardware - the military nearly always had their transistors on pads. If you're using old fashioned TO5 cans these can stop a mechanical shock detaching the track on single sided boards. I used to fit them to some makes of light dimmer pack for on the road use, cut down on repair bills a lot. These are free to those that want them, (and I'm posting a box to), whilst I have stock. Anyone else needs to send me an SAE. On a similar note, I've realised that I can give 4 people a bag of sixteen of those mylar 22n caps. Same rules.

I Have Boxes! Despite the quote of 4 weeks lead time, 20 boxes arrived today. Invoices will be going out soon, once I have checked the 'small packet' rate at the post office. Please let me know if you want crystal mounting pads with your order (Twin-X already noted), they are free, but I only have 22 spare sets. If I get 6 packs of JB weld they will be £5.50 plus carriage to you. If I get 12, they will be £5 plus carriage. To make the JB weld option go, I need 5 or 11 takers.....

<Quasimodo voice> The SIDs! The SIDs! They made me deaf you know......

I was thinking of a quite and dirty solution like his. A midi xylophone is a way better idea. If you were going that route, then the solenoid circuit might be worth doing some more work on. By using 2 DOUT's per solenoid, and a charged capacitor, you could get more than one level of strike, so emphasis would be possible. Something similar was used in line printers to 'fire' the hammers. I'll have a think. Normal current for a soft 'hit', fire the charged cap as well for a harder one. You're still going to need your transistors or ULN's - Solenoid current will fry a CMOS output stage, so an old PC with a little player program would make a good test rig, (even a 386 would do this, so a pc out of a skip would help you get the mech going). Solenoids are a pain to make. The plunger needs to be the right type of soft iron, or it will magnetise over time. then you need spools, miles of wire and a winding jig. Been there, done it, and still have a few scars, (helping restore a fairground organ, in pre MIDI days). There must be something that you could salvage for the job. I think you were very much on the right track with your relays with an extended arm. The old UK 'post office', (telephone), type would be ideal as they are very robust and reliable. By the way has anyone posted this before? Note the relays....

I've just paid £15.49 on 4 SID's, If I'd thought, I'd have bought 8 in one go. The charge is VAT at 17.5% plus a handling fee of £8. Thre is no actual customs duty. I do think this handling fee is excessive, but it's a lot better than that charged by some of the other mail companies, I beleive Parcel Force, (more often known as Parce Farce), charge a £20 handling fee. VAT is a fact of life - we're in europe, we pay it. Wilba has to put the full value of the chips on the package for insurance purposes. A friend of mine had a pack of stuff from the USA go astray, the guy sending had declared it as $18 worth of spares. This was a few years ago. It was, in fact, 1G of ECC RAM. The insurance paid him $18....... Something worth knowing. PCB's have VAT, but no duty. Full kits are regarded as the finished item, so carry duty for whatever they are. There is duty on a music synth. A PCB plus some parts sent as 2 packages is different. I think Kits from SmashTV are regarded as parts, because they don't assemble into a finished synth - they are general purpose modules, regarded as electronic parts. Things from Europe have no VAT or Customs duty, (VAT is already paid at the sending end). If you wnt something from Sweden, watch out, because their VAT is 25% ! As they say, life sucks, (but death doesn't put out at all).