Floppy Disc Looper/Delay + Other LG Dreams

[lordgalvar]

Has anyone on here ever attempted to build a floppy disc looper/delay? I know that there are some youtube videos floating around like this one:http://youtu.be/iuOPaumoefY. It's project page is here: http://www.openmusiclabs.com/projects/floppy-audio/the-basics-how-it-works/

I have some floppy drives around the house and I am going to try to adapt it for guitar. The guys on that board kind-of seem all about using old walkmans and stuff instead of building proper preamps and junk like that. Anyway, it may take me a while but I think I have a good layout on how to make it work like a more traditional delay but I might have questions specifically relating to guitar (impedences, frequences...amplifier classes...stuff like that). It's still in the planning stages as I figure out whether to continue with Arduino or use something like a 555-based pulse timer.

The people are basically using RIAA phono preamps and walkman preamps just to hear the output signal from the tape head on a mixer (the heads are very weak). Is this generally acceptable for the input of an effect that I plan to use in the effects loop of my guitar amplifier or should I plan on finding/building a different kind of preamp that would be ideal for my useage (and would it have enough gain)? Thanks for any input/pointing me in a good direction.

I think I is going to turn this into my random little place where I put my findings, ask for advice, and ponder random things. I will use this first post as a table of contents and order everything//create a docs like system. Maybe put links to random research. I love doing that stuff.

Project Links

>Floppy Disc Delay - [PROJECT POST] - [DEMOS]
>CV controlled switch - [PROJECT POST] - [DEMOS]
>CV controlled bypass loop (with trails) - [PROJECT POST] - [DEMOS]
>Intrument to CV-trigger - [PROJECT POST] - [DEMOS]
>Easy Peak CV-controller - [PROJECT POST] - [DEMOS]
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[REFERENCES/LINKS/RESEARCH]

[culturejam]

I actually looked into an older project based on a floppy drive. I just don't have the digital chops (yet) to make it happen.

I've been playing around with a few different ideas for a DIY tape delay, but all of them have major challenges that would likely make them unattractive to the general DIY community.

[lordgalvar]

Information is pretty sparse it seems. I know what you mean about the challenges though. This whole thing started as a tape delay which seemed daunting/expensive I thought of floppies and found that above project. I think I can get this thing to work but I have a feeling that the preamps are going to be the hard part. I've been documenting everything as I go so that hopefully it will help people in the future (I don't know if anyone would be interested though).

Use a second preamp (like something from a mixer) after the NAB tape preamp (which seem to be around 50db of gain), just the tape preamp, or the tape preamp and something like a boost pedal? I will trial-and-error it and research more. I'm thinking and typing...bad idea.

Thanks for the reply though culturejam and that cluster fuzz of yours sounds nice. Keep up the good work!

[culturejam]

What seemed most doable to me in terms of a DIY tape delay is to take the basic circuit and mechanical layout of Univox EC-100 and upgrade it to 1/4" tape via 8-Track cartridges.

[lordgalvar]

That's funny that you mention the univox ec100. I pulled my ec100 out of storage after I posted that, looked at the insides briefly and thought, "this is a good place to start". I was actually getting around to fixing the cartridge for it. Might just hold off on that. Those 8-track heads are expensive and why I switched to looking for alternative media. I will get around to doing one of those someday though. Thanks, bud.

[culturejam]

I have a EC-100 and two EC-80s. The basic idea of those is really good. But they would benefit from wider tape and heads that actually use the entire width of tape. But, I can appreciate the costs savings of going with off-the-shelf tape deck heads. I repaired the EC-100 with a tape head I got from a $8 boombox from Goodwill.

[lordgalvar]

I'm still working on this...it has just been slow moving.

Anyone got any advice between using a ton of relays or a few MUX chips to switch between paths?

Also, been kind of rethinking the whole Ardurino thing and might go for a 555 timer setup (which would make the build way crazier I think). Basically, the drives move based on pulse. The Ardurino (need to remember how to spell that one day) makes things easier in some ways but 555 stuff could create more wildness. Any thoughts from you all?

[culturejam]

Basically, the drives move based on pulse.

So you'd use the 555 to create PWM to drive the motor? I guess you'd need a stepper motor for that to work right. I don't know if regular old motors can be driven with PWM, but I'm way out of my element at this point.

[lordgalvar]

Basically, the drives move based on pulse.

So you'd use the 555 to create PWM to drive the motor? I guess you'd need a stepper motor for that to work right. I don't know if regular old motors can be driven with PWM, but I'm way out of my element at this point.

The old 3.5 floppies have a stepper motor used to move the arm/head. They basically take 5v in PWM in to step it forward and when the signal is cut I believe they step back on their own to the start point. The disk drives I got on ebay (despite my best magnifying glass) are too damn hard to work with. They are the more modern, smaller component ones. Going to try to find older ones. 555 would work but I think it could save me time using something like an Arduino because it has a 5v PWM out already (even though I could create weird, updatable modes with that). I figure either way, weird double play, offset rhythms and stuff can happen.

Hopefully, I can get the straight sampler drive setup (just one drive, either record or play). Basically I am going to use relays or a few mux's to switch between recording and playing. Should be able to get kinda-reverse delay.

I am already going to use a 555 as a bias oscillator to help erase the disk before writing so that there isn't ghosting. Unless someone has a better solution (I am pretty new to writing to a physical medium).

Thanks, man.

[culturejam]

Sounds like a cool project. Definitely keep the thread updated. I'll be watching with interest, and I'll chime in with input when I can. A lot of the digital stuff is still new for me.

[lordgalvar]

Will do, man. I just ordered some more floppy drives. I think these ones will be easier to work with. I will try to write everything down and document it well. Mirror it on my site too.

[KaosCill8r]

This does sound like a cool idea. Just a thought, would one of those bulky external 100 mb zip disk drives be better for this idea? Just might give you more room to work with. And you might be able to power it with a usb phone charger.
Though I might be missing the point. I'm an electronics noob.

[lordgalvar]

This does sound like a cool idea. Just a thought, would one of those bulky external 100 mb zip disk drives be better for this idea? Just might give you more room to work with. And you might be able to power it with a usb phone charger.
Though I might be missing the point. I'm an electronics noob.

I know people have used 5-1/2 floppies for this but they are getting expensive. I seem to remember reading about somebody that tried it with a zip and there was something different about the head.

Basically a floppy drive has just like 4 mini magnetic tape heads on the drive's head. I bypass the normal digital signal and send/receive to/from amps directly to the head. Everything works on 5v on these things, so they are kinda USB powered too.

The reason I am using 4 is because you can't read and write to them at the same time. I have to alternate phases between write/read/read reverse/write erase (bias writing to clear all signal).

I think each disk holds up to around 1 second. You could also store 4 (or more) samples and play them randomly/sequenced, have different staggered delay repeats (like drive A plays a 1 sec delay and drive B starts 300ms into drive A's signal). The reverse thing is also neat because while the stepper motor goes backwards, it can read the disk kinda backwards.

If I can figure out how to speed control the spinning motor on the drive, you can get some granular synthesis I think.

If I could pull off zip drives, that would be awesome (but I think to expensive right now). A drone device though? Maybe...we will see what happens.

[Twangasaurus]

Hey Galvar I might actually be able to get my hands on a zip disk drive and some disks if you're interested. I will have to ask a friend if it's still around. Would be happy to ship to you at cost if it works out?

[lordgalvar]

Hey Galvar I might actually be able to get my hands on a zip disk drive and some disks if you're interested. I will have to ask a friend if it's still around. Would be happy to ship to you at cost if it works out?

Let me look into it some more to see what I can find out about how the heads work. I wouldn't want to destroy something without looking into it more first. I will get back to you when I find out something. Thanks for the offer man!

Another thought I had was to actually record a drone loop with one drive, then basicually being able to play over it and FM or ringmod with it while still having a delay going (sans reverse or bias stage or something). I am going to have to figure this out, sequence-wise but I think the possibilities of 4 separate delay/loop setups is pretty awesome. I will post some diagrams when I find where I put them.