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[moordenaar]

@Gordon

I don't think remaking one would be incredibly difficult, however - the process of making some kiind of acetate disk might be.

Mmm no.. Pull out yor scissors ! Here you go, acetate for the masses.  



or



Maybe some karma huh ?

[Gordonjcp]

You could use an arduino to control the motor speed.  I don't think it's got enough grunt to do the DSP part successfully, and it doesn't have enough RAM.  By the time you go down that route, you may as well build a microcontroller-based sampler ;-)

Using a variable resistor to control the speed won't be terribly effective - low starting torque will be your enemy, and it will probably wow a bit as the load changes when the splice goes through the rollers.  What you need is a PWM controller, which will apply the full voltage to the motor, but only in short bursts.  The inertia of the motor and flywheel will keep the speed constant but give you that portamento, so there's a tradeoff.  Ideally what you need is to have some sort of speed sensor, maybe by drilling some equally-spaced holes in the capstan flywheel rim where it won't affect the belt, and using a light or Hall-effect sensor to pick up the speed of rotation.

You used to get old computer tape decks that had three motors, one for the capstan and one for each reel drive.  I was never successful at getting it to run slow enough to play back "ordinary" tapes, but iyou could record a nice long loop at high speed and haul the tape through faster.

If you want to go down the multi-track route, try contacting recording studios and pro audio repair places to see if you can scrounge an old 16- or 24-track head stack ;-)

[untune]

Ahhhh thats a shame, I only just found the Arduino and it looked pretty exciting with all the possibilities!  I think that would be the best way of implememnting keyboard control too, though all the tutorials I read were based on inplementing a keyboard matrix for a keypad or QWERTY keyboard rather than anything musical.

I had an idea of meeting halfway with the optigan and the mellotron, and instead of using cassette, use the tape, but wrapped round the circumference of a disc, say 3 inches in diameter.  Drive this directly with a motor, no gears, wheels, belts etc.  The tape head could be mounted next to the disc and then the speed of the 'tape disc' is adjusted with PWM.  I've been pondering the possibility of (somehow) getting my hands on an old DD walkman which used disc drive as opposed to belts.

A few people have had success controlling motors with Arduino and PWM, as per Youtube, but my only concern is whether that will stretch over 2 octaves.  The whole transport needs to do nothing but play back, therefore the pause, stop, RW/FF functions are all irrelevant, so I reckon the system could be simplified.  I've even thought about using one tape per octave, but that would complicate things where I'm striving to simplify

I do actually have a dead Tascam 4 track that needs repairing.  I'm not sure exactly what went wrong with that, I think the motor is dead so I can't test if the head is functioning.  With a 4 track head, using a single cassette, you could then (somehow - this is where I get lost) configure the 2 octave keyboard to have a track per 6 semitones.  Each track of the cassette could be a long sustained note at every half an octave.  So it'd have to be something like Trk1=C2, Trk2=F#2, Trk3=C3, Trk4=F#3.  Then the motor needs only know how to swap between 7 speeds (to cater for that elusive 25th key, which would be C4 in this case.)

I know that the actual melloman idea works great using 13 walkmans, but everytime I come back to that idea I think 'OK, where does one purchase 13 identical, high quality walkmans for next to nothing?'.  If I answer that question, I might have a starting point

[electoyd]

can you imagine some machine with 13 walkmans attached to it!  surely there must be an easier way to make music 

[jamiewoody]

electoyd, i think that is the same thing they said about the mellotron! lol

[untune]

I just think it would look/sound cool to have a really unusual keyboard with its own character and an analogue sound source

[electoyd]

Well go for it Untune, dont let my negative waves put you off.  Have you seen the machine built by nervous squirrel,  Its like 8 furby encased  (and bent) in a big box, he turns a big handle on the side which activates the furbys in turn almost like a manual sequencer, flipping through the crazed furby sounds.  Cool bit of work called the furby gurdy or something like that, but its always good to hear about someone thinking outside the box, even if the results could probably be achieved easier using other means.

[untune]

Well go for it Untune, dont let my negative waves put you off.  Have you seen the machine built by nervous squirrel,  Its like 8 furby encased  (and bent) in a big box, he turns a big handle on the side which activates the furbys in turn almost like a manual sequencer, flipping through the crazed furby sounds.  Cool bit of work called the furby gurdy or something like that, but its always good to hear about someone thinking outside the box, even if the results could probably be achieved easier using other means.

I've not seen that actually but it does sound cool!  I'll have a look for it

Yeah, I understand what you mean.  It does seem to be a bit of a long way round, but the 'easiest means' aren't always the most enjoyable

My mini reel to reel recorders arrived today anyways, so I reckon a little bit of restoration and the contruction of a tape delay should suffice til I've had time to think this one over

[electoyd]

I have an old copicat reel to reel delay box that i got given there is something quite cool about the old tape echo boxes, good luck with your project dude!

[Circuitbenders]

I'm not sure this is relevant in any respect but a couple of years ago i got hold of a thing called a Recordon which is some kind of very early dictaphone made in the 1940's. It uses a circular magnetic disk and a read/write head on an arm which is mounted in a spiral groove so it moves towards the centre of the disk as the platter rotates. Imagine a writable vinyl deck, only nothing like what you're thinking of  

Unfortunately its full of valves and the guy i bought it from obviously had something against packaging as he just stuck it in a box that was way to big and posted it. After rattling around through the post for a few days it wasn't really working 100% afterwards and i don't have replacement valves.



Theres a bit more information here http://home.kpn.nl/kalma99/Recordon/Recordon.htm

[Gordonjcp]

Create a topic, and post a pic of the insides and a list of valves.  I'll see what I've got, although 1940s valves may be hard to track down.

(Edit)
This may be somewhat related:
http://ftldesign.com/Timex/index.htm

The square boxes are "Triode Couplates":
http://glowbugs.net/CentralabPEC.pdf

(Further edit)
From http://www.vintage-radio.net/forum/showthread.php?t=47365 ->
"""The scrolled plate ensured compatability with other Timex, and I suppose Mail-a Voice/Recordon, machines.
I understand that the "plane" spiral groove could be made "wavy" for security and when used in matched pairs the message could only be read by a machine with the corresponding scrolled plate. Many different pairs could be made by varying the position of the locating peg on the same scroll. John. """
So, by using a different wobbly spiral you could disrupt the recording, presumably playing back garbled fragments out-of-sequence if you used the wrong wobble.  Can anyone else see the possibility of this sounding rather dope when applied to drum loops?

[selfpreservation]

great name for a band WALKMAN MELLOTRON yeah

[untune]

That's a very cool piece of gear

I think the best way to think about this thread now is 'how can I play back a magnetic recording with a keyboard?'

[moordenaar]

Can anyone else see the possibility of this sounding rather dope when applied to drum loops?

Instant break core FTW !

circuitbenders what do you want for your Recordon ? 

[Circuitbenders]

I'll start another thread on the recordon when i've had a chance to look inside, otherwise this is going to go wildly off topic.

Cheers for the links Gordon, and the valve related stuff you sent me via PM Untune