TheAncientOne

Nice site Stryd! Though I have one reservation: I think there may be some kind of measurement system artefact in the distortion graphs - with the exception of the HD25's, most of the cans tested seem to have a horrendous 100dB distortion 'spike' are around 380Hz, followed by a string of harmonics. I'm wondering if there is a resonance in the artificial ear they use for the tests. Wierdly, Sennheiser quote the HD25 as "<0.3%", whereas they are smoother than the same companies phones quoted as "<0.1%". Tricky things transducer distortion measurements. Control room speakers is another whole can of serpents, (worms just aren't enought to describer the problems!). I rmember once bing in a small room, dominated by a huge pair of Genelecs. I could hear things different by moving my chair backwards and forwards behind the console. The engineer, (and as I found out the studio designer), did a full diva routine when I pointed this out. In the interests of getting the session finished, I left it. A week later a I got a mildly apologetic phone call, (and from this guy that was pretty awesome), due to the relative heights, there was a noticeable treble diffraction over the consoles meter bridge. They'd done some serious work and by moving the cabs and a few other things, had killed the problem. I still think they were way too big for the room myself. Haas anyone noticed how the HiFi people seem to go totally opposite to audio engineers? In an LEDE room, designers will go to great lengths to decouple the speakers from the building structure. HiFi people spike theirs to the floor. they say more rigid, LEDE people talk about structure transmitted bass giving 'early early sound' and blurring the bass transients. I tend to be more on the side of people who measure than that of people who will pay £10/metre for speaker wire. Later this year I'm doing a 'back to basics' music system. E J Jordan single drivers http://www.ejjordan.co.uk/drivers/jx92.html pushed by Linsley Hood Class A's, http://www.tcaas.btinternet.co.uk/index-1.htm (and that was an early school project that I just about got right - all good bar a slight mains hum). If you don't need massive power, then I recommend the late JLH's design to everyone, a very satisfying amp for a low price. (I'll now start rolling up my ball of string and meander back to the subject...). Mike

Noted. Thanks. A short list is building here. I've been there with the salesman too: took in my own CD player and discs, including one of stuff built from CSound. I ended up negotiating a bit of extra discount in return for the CSound disc - it had a rendering of Kim Cascone's "BlueCube" on it, which sounded awesome. Sadly the Dynaudio's we bought weren't for me, they were PPM2's, and at the time they seemed the most accurate, ruthlessly honest small speakers I'd ever heard. Same deal with the guy's face too. He'd been trampled by two bullproof audio engineers, made to plug and unplug a whole array of smaller units, and haggled with in a style that can only be done when you haven't actually got anything like the list price. His final tentative 'how do you want to pay for these?', turned into a huge grin when the engineer from Crescent said 'Pictures of the queen mate', and produced a wodge of £20's. Mike

Being a bit out of touch with favourites, and 'States of the art', I'm looking for hints as to good cans to audition for the time, (soon I hope), when I get back to doing some serious personal audio work. I tend to do a lot of preliminary work using phones, to avoid upsetting the neighbours. I have a preference for European phones, because I can keep them running and get spares, (I've got a pair of DT100's that are on their 2rd set of earpads - and are still good - but not really any kind of reference by modern standards). In the past. to me, the gods of headphone design were called AKG, Beyer Dynamic and Sennheiser. I'm thinking of closed back types in case I do any live work again. Anyone reccommend their favourites? Thanks Mike

You're sixteen and have built and troubleshot a MIDIbox core. That's pretty tweaky to me. At sixteen I was having trouble building fuzz boxes that worked first time, (and we're talking about 15 parts here!). One day soon I'm going to build a radio kit - and make it work! From my first attempt at 11 to the last time I tried (18), I never ever got a radio kit to receive much of anything. One definition of an expert is "a person who has made all the possible mistakes in a narrow field". Some of the most important abilities are those that relate to finding and fixing your mistakes. Electronics offers a huge range of ways to make a technical fool of yourself. Add music,and you've got the ability to do it in front of an audience.... Perhaps we could do a thread. Believe me, putting one resistor in wrong doesn't come close to an early repair job of mine, where I replaced 4 very expensive power transistors in a hifi amp ..... the wrong way round, because I'd taken them all out when I tested them. I lost 2 weeks pocket money in 10 seconds. That was an early lesson to keep notes, and that NPN is collector Positive, PNP is collector Negative You're doing fine - just keep on going. Mike

I love the video for "Daft Punk is Playing at My House" Love to see them live. Mike

How does your drum box work now JRP? Some take what is effectively a variable width single pulse as a result of the strength of 'hit' on a piezo sensor, and some have a velocity voltage done as a sample and hold on the pulse. Since you're not doing fine tuning here, the AOUT_LC would be fine. If you only need an emphasis effect rather than a full range, perhaps there might be a way to double up the 48 auxiliary trigger outputs, to give 2x24 emphasised triggers, (in fact it might be possible to do trig1, trig2, or trig 1+trig2, thus giving 3 levels). This would need some coding, but perhaps be less messy than trying to hack something more ambitious. That way you could have 32 triggers, 8 with 8-bit CV, and 24 with 2-bit CV. Another thought, though TK would have to pronounce on this one, is tha it might be feasible to split the existing AOUT_LC into 4 bit sections, giving a max of 16 4 bit D->A converters, which might be enough for a lot of percussion work, though I say this is just a mad brainstormed idea, and I've no idea how feasible it might be. If you are planning a MIDI controlled Gamelon Orchestra, I realise this may still be a problem.... Mike

Yes. I think they should at least have made the pattern system open-source and provided an I/O port. I'd like one enough to put down the money for a kit, though it looks a fairly tough assembly job. @Wilba They are a bit similar, Von Neumans generate the next row displayed by applying rules to the previous row, and so on. generally a pixel/light will be controlled by three on the row above, ie the one directly above, the one to the left and the one to the right. assigning values to the colour or stae, and using this to determine the next state. It can be very hypnotic, and there are lots of rule sets, and you can do a pre-determined or random 'seed' row to start things off. If you want to play with them (WARNING - Additive!), try CelLab http://www.fourmilab.ch/cellab/ By the way - it is quite possible to make them play tunes, though my last attempt was on a BBC micro. Best wishes Mike

Dear Micha DMX is a Protocol, which runs over the a physical RS485 cable network. MIDI sequencers are not usually that good at sending DMX command sequences, because their natures are very different, and some things, say a light 'pan', can require a whole list of commands sent at the right intervals to the same device, (I use the term 'device' rather than simply 'Light', because DMX can control a whole slew of things from light dimmers to 'Wobbly Mirror' lights, projectors - and even smoke machines), and the command structure is a bit diffrent. DMX also requires faster transmit speeds than MIDI. I posted a note on some 'home build' USB <-> DMX systems, and there is a lot of free DMX control software around, usually PC based. A PC is a good host, and the MIDIbox could be used to provide a control surface connectng to the PC through a MIDI or serial port. Mike

Nice. You could run a Von Neuman Automation program on it. Wouls certainly look cooler than the Daft Punk coffee table, (nice try guys, but a new record would be better)http://www.youtube.com/watch?v=zCA79Du-WqY, but not quite as sexy as a Hypnocibe, for mehttp://www.hypnocube.com/ Mike PS. Anyone want a hypnocube built? I want one, and figure on cutting my costs by assembling one for someone else, (at a small fee).

Nice sounds! Though using more than one oscillator does help. Some gated reverb or a similar comb-filter trick can 'phatten' up some quite unremarkable bass, too. Have you ever checked out how Sony's "Mega Bass" worked? Interesting trick that could possiblt be replicated as a VST. Mike

Looks good to me. Star point grounding is usually best for this type of kit - keep the main ground junction in one place, and use decent cable. For some audio uses, a 'ground lift' switch may be needed to stop hum loops. Hard wire the mains safety earth to the metal of your casework, transformer exposed metal etc, but have a switch, (or moveable link) between that and the electronics earth. The switch should not be 'immediately accessible' - like on the back panel or under a cover. Some pro kit has a 'ground lifted' light on the front panel, so if you do get a horrendous hum, you may know the symptom. Stryd may be the best nameity on this one I think. Mike

Just noticed something else: at TR2, if the windings are normal, then the two centre points should be joined, so as to get antiphase, about the centre tap, on the two ends. This is sometimes only checkable with a dual trace 'scope! Otherwise you won't get a smoth +/- voltage ripple. This depends very much upon the transformer used. most 0-12 0-12 rtranformers can be wired as 12-0-12. Check the data on the transformer itself (sometimes there is a picture), and make sure your centre connection is the '0' of one winding connected to the '12' of the other. Dropout Voltage on a 7805 is usually 2 volts, so the minomum input voltage, with max current draw has to be 5 Volts. You really need some margin here, and I would never feed less than 8 myself. If you need to read up on this, the very best, "No bull****, here's the electronics" book is called 'The Art of Electronics" , by Horowitz and Hill. There is a website here: http://www.artofelectronics.com/index.html Chapter 6 deals with power supplies, and you can have fun spotting what is wrong with 'Bad Circuits' at the end of the chapter. Mike

In the 5V side of your design, I would suggest just one big bridge rectifier and (say) 4700uF, feeding two 7805's. A 100nF ceramic across the 10uF's wouldn't hurt either. Did you know that you can get 7805S, which will supply 2Amps? The reason for using 1 bridge is that the diodes may vary in the seperate bridges, and there might be a wierd ground current. It's a bit cheaper too. I much prefer seperate transformers for the 5 and 12 volt supplies. Mike

You may be a little out of luck with a SID, it sounds like part of this a high resonance Low Pass Filter swept by a note triggered envelope. Other part is some kind of two osciullator soft sync, at my best guess. I don't know enough SID yet, to know if it is possible. The 'Little Phatty' is definitely the Mini-Moog for the 21st century. On similar lines, I hope I can get a SID to do something like this: http://www.colinfraser.com/m5000/syncron.mp3. This is only a partial sample, because I haven't got anywhere to 'park' one of my own. It's an early digital, the 'Music 500' add on for the BBC Micro, which had a discrete component DCO system in it. Mike

The second Rapid reference is the crimp on one: their part number 80-0205. If you can't make a £30 order, rapid will charge you postage,,whcih could make for and expensive cable!. I order about once a week at the moment so could easily sort it out. What do you want on the other end? I've used both with Turned pin sockets, some tend to be a little loose, and the turned pin headers, (they make them too), can be rather tight. Mike

Listen to one of these http://www.oakleysound.com/tm3030.htm Samples on the page. You been standing in too many bass bins? Anyway, you want that high density comb filtered bass effect, then the multi SID should give you binsfull, if your programming is up to it. Meanwhile, do you mean this? http://www.analog-synth.de/synths/mod2/ssmlowpass/ssmlowpass.htm Edited to add - also http://www.oldcrows.net/~oldcrow/synth/korg/polysix/manuals/service/miniserv.html Remember: "Google is your friend" Best wishes Mike

The thing you are looking for is called a Dual In Line (DIL) Header. Thye are available as solder tagged parts, often used for mounting small parts on an IC socket - I use them for Vactrols, and for the 8 current limiting resistors ina display driver, (I can easily plug ina different set if I need to change the brightness). They are also available as Insulation Displacement (IDC) connectors, where you crimp them on to a piece of ribbon cable. To do this you either need to buy a special tool, or to make a spacer that will fit closely between the pins, and then squeeze the the cabel anheader togethr in a vice. If you only need one simple cable, and aren't too sure about doing this, then, since you seem to be in the UK, memo me and I can make one up for you. http://www.rapidonline.com/productinfo.aspx?tier1=Cables+%26+Connectors&tier2=Connectors+-+Multipole&tier3=DIL+Sockets&tier4=DIL+slotted+headers&moduleno=60996 http://www.rapidonline.com/productinfo.aspx?tier1=Cables+%26+Connectors&tier2=Connectors+-+Multipole&tier3=IDC+Connectors&tier4=IDC+DIL+Connectors&moduleno=63705 http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?D=IDC%20DIL%20header&Nr=AND%28avl%3auk%2csearchDiscon_uk%3aN%29&Ntk=I18NAll&Nty=1&Ntt=IDC%20DIL%20header&Dx=mode%20matchpartial&Ntx=mode%20matchpartial&N=0&name=SiteStandard&forwardingPage=line&R=0471373&callingPage=/jsp/search/search.jsp&BV_SessionID=@@@@0174229551.1178794736@@@@&BV_EngineID=ccdeaddklggfklgcefeceeldgondhgf.0&cacheID=uknetscape Hope this helps Mike

On a similar, though not exactly, topic, try googling for 'Triadex Muse'. Thre is a software version arund the freeware places too. Mike

Sorry! I had read the SID 'C' LED driver drawing wrongly, and thought the outputs were current sink. not source. The best idea I can come up with is to use an 8 way darlington High Side driver like UDN2981, with a variable voltage drive, that way you have 5V logic in, but anything up to 50V source out. The UDN's are nicely laid out with all connections 'in line', so are easy to fit. I've used them, and the UDN2000 series low side drivers, for LED matrix displays before, and they work well. Mike

Why not run an LM317 off the unregulated supply, and supply all the LED's from this? Since you can control the LM317 with a simple pot to ground, a dimmer knob os possible. Or a simple switched resistor bank run from a DOUT, whch finally could be software assigned. Just a thought Mike

Told him not to use a cheap switchmode..... Seriously, the military consoles look very cool, all the more surprising when you consider that ergonomics are everything and there's not a stylist in sight. I need to get down to Bovington and take a look at the Challenger 2. I hadn't even thought of tanks - last ones I had anything to do with were strictly old school. I would love to do a CS like that - it could have envelope graphics, waveform displays, the lot. Though I think my entire studio will be equipped for less than the display module cost in the picture. Like the cute robot said "Input! Input!" Thanks again Mike

Thankyou so much for this - a hell of a lot of work, and most appreciated. I know most modern cockpits are glass and (horror) have soft keys and virtually no labelling. I thought of the look I've seen in some MIL kit I've worked with, as well as the Boeing cockpit I looked at a while ago, more neutral grey than black. The blue display is for my MIDIbox monitor - just because I found a nice Hammond transparent blue box, and I won't have to cut a hole or make a bezel. P3 will have a green or, if I can sort it, a red display. I've got Re-An soft textured knobs in black/white and black/grey, and charcoal Cherry buttons with clip tops for labelling. I had initially planned to have a back engraved plastic panel done, but was worried about reflections, so now I'm not sure. I will be experimenting with edge lit panels, I saw some Korean war era panels that were black screened perspex, with white lettering, and embedded lamps, not that bright, but good low light visibility. I may have to go for some other LED's, Colin used red/green dual colour LED's, but snce I have a bit of red/green colour blindness I might replace them with a red and a green row - getting a spatial indication as well as a colour one. (Sorry to TK for heretically discussing a non-MIDIbox sequencer, I just got lucky with one of the last sets of PCB's). Initially I know I won't get the surfaces right, and have planned for a re-work, doing my own metalwork for the first lot. Eventually I want a rig with a consistent look, that is easy and intuitive to operate. I figure the military have done the most work in this area, and I should follow their lead. I'm looking forwards to the day when some reasonable big LCD graphics panels come cheap, then, using CAN, we could have a programmable MIDIbox panel, perhaps using a mixture of buttons and switchable encoders around the edge, which could be used as a standard CS, and user customized at the graphics level The end result will be for the future: my eyesight is failing, (I've only had one fully functional eye since being a kid, and now the other one is starting to go). I can solder well enough, still, with decent light and a magnifier, but later it's going to get worse, and I want to be able to use the stuff easily later on. I've been looking at big displays too! I'm doing some valve/retro audio stuff too, based on the Gyraf DIY stuff - I think I've seen you there too. For that gear I've sourced some of the cream Traffolyte that engraves to dark brown, and found some very good quality old bakelite knobs, so should look like some old Solartron gear from the 60's - which is a bit in line with the Navy look you mention. Sitting in a box I found two SEW VU meters, the clear square ones with a cream face, bought for a mixer I did at school, and never used, so they finally get to live a little on my compressors! Some analogue synth stuff really winds me up: random piles of knobs and jacks that get in each others way, (some Plan9 stuff would be almost unusable fully patched), and a design aesthetic based on a high quality version of the Moog Modular. EMS stuff was so far ahead of it's era, just a pity the electronics of the day weren't quite up to it. Did you ever see a Spectre - a video synth in the 70's? One of the things that I find most attractive about the MIDIbox community is the diversity and quality of design. On another track, some Tektronix and Agilent gear is beautiful, though the older HP stuff often beats the recent, I used to love the look of Neve and SSL desks, and have felt like throwing rocks at one or two other console designers! Thansk again for the lighting stuff, very interesting. Best wishes Mike

We're getting very close to the point where you have to say: "OK, I've fought this one down to the wire, but that's it". A few thoughts: do you hvae details of the make and model number of the supply itself? Can you give me some of the main chip numbers. I think you've done pretty good so far, but I need a little more info. Mike

BC549 is only 100mA collector current rated. 2SC3203 is 800mA. BC337 is much better. I've got quite a few. Use the one you are saving, memo me an address and I'll post you one. (you are in Europe aren't you?). Mike

Thanks Pather: one of their distributers is about 20 min from where I live. I'll ring them next week. If I can source a 20x2 red backlit LCD, who else is interested? I would like a 16x2 red negative to go in my P3, I'm trying for a sort of aircraft instrumentation look, grey panel, white lettering, and green/red displays. I notice that some eastern bloc military aircraft use blue panels: has anyone any feedback on the best low light visibility? I kind of thought that if anyone has got the art of designing ergonomic panels that can be read easily by stressed people, then the aviation industry must be my best bet for examples. Mike