portable tape player to tape sequencer

dnny

ok so since i saw this tape sequencers made by Gijs Gieskes

the one whit logic sequencing
Posted Image, might have been reduced in size. Click Image to view fullscreen.

and the one whit mecanical sequencing
Posted Image, might have been reduced in size. Click Image to view fullscreen.

i have wanted to make my own - and because Gijs has no information on those beasts.
( Gijs page)

finaly i choosed to go my own way . . . but i need some help

first i got this cheap portable casette player "unisef z-50". opend it up and tryed the motor - but i found out that on low voltage (slow playback) the motor doasent have the strenght to roll. so i savaged and old VCR. and found nice powerfull DC motors for the job - the problem whit the bigger motor is that it draws more current so i can´t draw the voltage straight from the chip as i planed in the first place - this is my first plan :
Posted Image, might have been reduced in size. Click Image to view fullscreen.

so now i have CV of about 0 to 7V

i have one of thease KEMO B 184 kits (adjustable PSU) that looks like this :
Posted Image, might have been reduced in size. Click Image to view fullscreen.

it gives the suffisent voltage to my new motor (0 - 14V)

so the final question is how to make this power supply controlled whit the controll voltage i get from my sequencer unit (0-7V)?

thanks in advance and sorry for this confusing post.

here is the motor whit the player:
Posted Image, might have been reduced in size. Click Image to view fullscreen.

daniel

and here are some mp3´s whit Gijs tape sequencer sounds

TapeSEQwithDoormouseAndLSDj.mp3

Description:

tape sequencer whit doormouse + LSDj

Download

Filename:

TapeSEQwithDoormouseAndLSDj.mp3

Filesize:

1.84 MB

Downloaded:

1415 Time(s)

TapeSEQwithGUITARandLSDj.mp3

Description:

tape sequencer whit guitar +LSDj

Download

Filename:

TapeSEQwithGUITARandLSDj.mp3

Filesize:

1.93 MB

Downloaded:

1423 Time(s)

v-un-v · Posted: Fri Sep 30, 2005 5:22 pm Post subject:

dnny,

those tracks are demented- well done :D

more?

Blue Hell · Posted: Fri Sep 30, 2005 5:48 pm Post subject:

Especially the 2nd one has a weirdness that I like.

You're almost there, just multiply the control signal by a factor of two and add some 1.2 .. 1.4 Volts and then connect the output of that straight to the base of the darlington, deleting 220 R, 15 Volt zener, etc.

This multiplication by a constant and addition of an offset is standard opamp stuff as you've seen it in the soundlab already, probably.

When you want me to beam up a proposal just let me know & I'll photograph what I just sketched here.

dnny · Posted: Sat Oct 01, 2005 1:34 am Post subject:

Blue Hell if you have the proposal ready - beam it up - please. so i can get this thing running - i know that im really close but still there is just this few things that i need to learn...

Uncle Krunkus · Posted: Sat Oct 01, 2005 4:49 am Post subject:

Gijs is a seriously out there kinda person.
The world needs more people like that.
Very cool.

Blue Hell · Posted: Sat Oct 01, 2005 7:06 am Post subject:

Something like this I was thinking.

The first opamp amplifies the signal by a factor of minus two and it adds some offset that can be set by the pot (which I specified as R, but the 100 k pot of the original PSU will work as well).

The 2nd opamp makes the signal go positive again, a plain invertor.

The two capacitors tame the thing a bit. You might want to add a capacitor of something like 470 nF between the wiper of the offset pot and ground to make it less jumpy in case it's quality is not too good.

The opamp can be almost anything, I think the good old TL071 series is still in fashion these days - I saw it used in the soundlab I think ?

The only thing is it needs a dual power supply of about +/- 15 Volt, which might be a bit clumsy for this partiular purpose. But to get around that it goes beyond just a bit of sketching for me - I'd need to breadboard it.

Ideally for motor control you'd want to have some feedback involving the actual RPM's the motor makes, or the current that flows through it. A circuit without feedback will only get you sofar, but when the motor has enough power and the flywheel is big enough it might work.

001.jpg

Description:

just a sketch

Filesize:

151.79 KB

Viewed:

26194 Time(s)

dnny · Posted: Sat Oct 15, 2005 3:50 am Post subject:

thanks Blue Hell

i think thats too complicated and hi-end for me - i need something
lo-fi and simple.

i have thought to use light dependent resistor or light dependent transistor to feed the power supply darlington transistors base (shown on the pic as red spot) and have the CV from the sequencer unit to light up a LED that is coupled whit the light sensing component on the power circuit.
so the component should go between the pot and the base of the darlington tranny (the pot would function as master speed)
Posted Image, might have been reduced in size. Click Image to view fullscreen.

mosc · Posted: Sat Oct 15, 2005 7:53 am Post subject:

Dnny, this guy is too good. I posted something about him on Online Music, http://electro-music.com/forum/topic-8235.html If you know how to contact him, please let him know about it.

gsga · Joined: Jul 22, 2004 Posts: 267 Location: allentown, pa

I know little about electronics, but I'm psyched! I think I'm just going to crack open a walkman and start messing around with it.

On battery power, of course. Very Happy

deknow · Posted: Tue Nov 08, 2005 9:50 pm Post subject:

...in college, i had friends that did a lot of transcription of jazz solos (i did very few myself). tuning the particular recording to a piano, or even slowing things down to make it a little easier to hear the individual notes was a thing everyone wanted to do. i made a few bucks putting a hole in the right place to stick a screwdriver in and adjust the motor speed of various walkmen and boom boxes.

deknow