New intrument!

[jorg1234]

I've been thinking about making this super analog instrument based on multi track cassette/tape-loops. A variant of the mellotron.

This is my theory:

8 track (or more) cassette/tape-loop running with different tones on each track. The different tracks a fed into a kind of mixer, which is where my trouble starts, because I'm to much of a noob to understand what parts I need to put together to make this mixing device work properly.
It needs to have the ability by the press of a button to open the sound for one track, playback while you're holding the button, and fade it out with the release of the button... I'm not sure which components could make this happen. Could I do this with a VCAs? or maybe even simpler, only with caps and resistors in a passive way?

Maybe it sounds like a crazy or boring idea for some people, but I'm very enthusiastic about it! ...
Anyway, ANY suggestions would be very much appreciated! !

- Jørgen

 

[lernith]

You should study up on envelope generators for modular synths.  Wikki is a good starting point:
http://en.wikipedia.org/wiki/Envelope_generator
And Music From Outer Space has some good practicals:
http://www.musicfromouterspace.com/analogsynth/AAA_EnvelopeGenIndex.php?page=ANALOG
Basically you need to feed a constant signal from the tape loops into a ADSR envelope and gate the ADSR with the keys/triggers/whatevs of your  instrument.  If you want each loop to have its own attack/decay pattern, then you'll need one ADSR per loop and to either daisy chain the potentiometers' shafts, let each loop's envelope be independently adjustable (which might be just what you need if the samples are quite different), or use digital pots controlled by a solitary panel-mounted pot.  After that, it's hard to walk anywhere in this forum without stepping on a mixer design (and I mean that in the best possible way).
I always find that the hardest part of studying anything is working out the local lingo.  These two resources will help you out in that regard, and your enthusiasm should carry you through....
I don't know much about synths, but if you get stuck anywhere along the way just holler. 
Did I just say holler?  Gross.  Anyway, hope this helps.

 

[PRR]

> ... ... fade ... ...

 

[jorg1234]

AHA! Thank you maaan .. Why didn't I think of that?
This is going to be a piece of cake now  ;D .. maybe not, but at least I understand what it is I'm going to make.
-> A synthesizer without the actual sound generators, and just feed my tapesignals into it instead

Thanks!

- Jørgen

 

[Winston OBoogie]

I was also thinking some little opto-resistor packages.  A series and a shunt one would give you more "off".  Play with the time constants for Attack and Release. 

 

[PRR]

> opto-resistor

Yeah, sweet.

My plan needs six whole parts per chanel. And it won't take large inputs well, has high loss, has to be tarted-up with input pads and output amplifier. And the total sound swells as more inputs are played chord-style.

The LDRs don't allow simple time-constant control. But a series LDR for each channel is likely to give a musically benign fade (rather than an abrupt click), the output is the average of the enabled inputs, and is dead-simple. Choice of LDR plus use of incandescent lamps gives a good slow fade.

All these simple 1-device tricks have poor OFF rejection. But if you go to 2-device tricks, you might as well go all the way to a '3080 VCA. The outputs can just be paralleled. The replacement for 3080 has a buffer to give low-Z output. Plans are out there.

You could also mount short-throw slide-pots vertical with springs.

 

[Winston OBoogie]

A good friend is a Mellotron and Chamberlin user.  In his house is the nicest, cleanest Mello on the planet, bar none.  In his studio: 2 Mello's and a Chamberlin and, in our joint storage, 1 Mello, 1 complete Chamberlin and parts for two others.

Anyway, another thought regarding fade outs:
Inside a couple of his units he has an inexpensive, old Alesis microverb - tens of $ on Ebay - and it sounds great! when everything's going through the internal pre and power amps.  Just adjust the mix between wet/dry on the Alesis and pick the setting that suits.

Also, you could do what 10CC did on "Not In Love" and just send each tape loop through a board fader and play the faders?

I like PRR's 'short throw slide pots on a spring' though  


Edit:  this whole thing gives me fond memories of seeing film clips of Delia Derbyshire and the BBC 'Radiophonic Workshop'.  
Building 'instruments' with 12 tuned lab oscillators because Bob hadn't given us the Moog yet.  Great stuff!

 

[Winston OBoogie]

Here's an MP3 file you might recognize. Still great after 46 years!  Very Organic, like some futuristic (in 1960's terms) or alien life forms were playing it.   This is Delia playing with chopped up bits of tape, sweeping oscillators by hand, filtering, delaying and, generally being WAY ahead of her game.  Remember, these sounds were created in 1962 and 1963, before synths!

Hope this isn't a copyright violation of some sort? Anyway:

http://www.upload-mp3.com/files/46734_yzkah/DD%40RW.mp3

 

[jorg1234]

Oh! I love the spring pot idea! . that would be soooo organic and dynamic to play with, looovely! Do I have to make them myself or can they be bought?

 

[PRR]

> Do I have to make them myself or can they be bought?

8 short sliders, $30 or less

Most good hardware stores (and junkbins) have a selection of these.
http://www.acewirespring.com/spring-guide.html

 

[mcfarlane_audio]

have any of you seen the melloman??

http://www.mysterycircuits.com/melloman/melloman.html

thats all ive got 8)

 

[Winston OBoogie]

have any of you seen the melloman??

http://www.mysterycircuits.com/melloman/melloman.html

thats all ive got 8)

Yes!      Was just talking about that today with my friend who has the Mellotrons.

Cheers

 

[jorg1234]

the big difference between the melloman and this instrument is going to be two things. First of all, this instrument is going to be played on springed slide pots, which gives you full control over the dynamics of each tone. Which actually is veeeery cool! I think anyway... Mellotron and melloman only have one velocity = boooring .. no, just kidding, but it's a big difference, that's my point. The other thing is that you only need one or two tapeloops because it uses 8 track recorders, (or anything else) so the samplng is going to be easier, and ofcourse to change sounds. .. you only need those sexy 8-tracks ofcourse .. I'm imagining that there's no piano keys on this instrument, but instead some kind of device that fits in you hand .. ? maybe.. we'll see

 

[smallbutfine]

Nice!!
Romantic!
Something for the recycling of the old portastudios we all may have in a garage closet somewhere  (ok, an old tascam 8-track tape maybe nicer but much more expensive(?)...).
Great ideas here. Velocity is a very nice thing to have and gives it much more unique and interesting instrument appearance.
Cool.

 

[MrZpliff]

the big difference between the melloman and this instrument is going to be two things. First of all, this instrument is going to be played on springed slide pots, which gives you full control over the dynamics of each tone. Which actually is veeeery cool! I think anyway... Mellotron and melloman only have one velocity = boooring .. no, just kidding, but it's a big difference, that's my point. The other thing is that you only need one or two tapeloops because it uses 8 track recorders, (or anything else) so the samplng is going to be easier, and ofcourse to change sounds. .. you only need those sexy 8-tracks ofcourse .. I'm imagining that there's no piano keys on this instrument, but instead some kind of device that fits in you hand .. ? maybe.. we'll see

Hmm, really COOL idea ! I've got an old 16 track Fostex that I have no use for...  
well, now I think I have  ;D was thinking about building something like the melloman, but
16 tracks felt like a few to little...