DiY Tape Delay?

[Jeremy Garber]

Ya, I've thought about that limited space for head contact on cassettes. It may turn out being something ripped from an old reel to reel, and having to construct my own transport. Definitely a challenging project. At least for personal use, it would be worth it to me to find a way to do this.

[Jeremy Garber]

Hmm.... thinking...

What if delay time was done using an IC? Basically using the tape transport for coloring the sound, instead of actually controlling the delay time. So, it would still be record head -> playback head, but the feedback loop would have an IC in the path to control the delay time. A sort of hybrid tape/digital delay? I really don't want to build a transport from scratch to accommodate head spacing... lol

[alf]

I have been looking into this also.

One of the more complex things I have run against is making the space between the tape heads and the tape correct(don't think I'm putting that quite right...)

[Jeremy Garber]

I have been looking into this also.

One of the more complex things I have run against is making the space between the tape heads and the tape correct(don't think I'm putting that quite right...)

Ya, I'm not quite sure I understand what you mean. Any way you can elaborate? Are you building your own transport? That seems to be the way to go if you want the playback and record heads farther apart than they are on a normal cassette deck. If you go the route of building your own transport, I would look at reel to reel transports and see if you can modify one to fit in the box, but that would make it significantly larger than what I have in mind (see Echoplex).

Or are you talking about how the heads engage the heads? I know some nicer decks used electronic motorized controls to engage them, as opposed to a direct lever attached to the playback/record buttons. I'd like to use the electronic type, so that when you stomp the switch it will auto-engage the heads for you. This is a tricky part of my idea that needs further investigating.

[signorMars]

maybe you could cut two cassette tapes in half lengthwise and glue the two bottoms together, so that you have 2 tape access points and then take two tape transports and attach them with one on top of the cassette and one below... for lack of a better description... as if they were doing the asexual magnetic tape 69... one of the 2 transports would actually only need the head assembly, not the transport itself i guess... then you could vary the speed on the motor to change the delay time. i think this would give you about 1-2 seconds of delay at regular speed, since cassette tape runs at 1 7/8 ips, typically. you would have to rework the tape path a bit or just make it a loop and route it such that the reels still move the tape.

the output of the second head assembly could be routed to a potentiometer that sets the level that is mixed into the output (a mix knob) and then a second potentiometer that is fed back into the record head of the first tape transport (feedback).

man... now you've resurrected my desire to build a cassette delay.... time to go buy some $3 walkmen.

[Jeremy Garber]

LOL! The asexual magnetic tape 69. hahah That's what the pedal should be called. Believe it or not that brainstorm had popped into my head while making my last post to this thread. However, it goes against my desire to make this pedal easily recreated in case others would like one. Trying to keep the fabrication to a minimum. I want to use readily available parts.

I think I need to check out some schems for digi delays, and see what ICs they are using. I really think that would be the easiest way to go (using a delay IC in the feedback loop). Bets of both worlds.

And my wife has dubbed this pedal the "Delay-O-Matic" and I so want to append a very large number at the end of it.

[Teacher's Pet]

I decided this thread needs more pictures.


I have a bunch of less-than-functional cassette decks I'd like to get rid of. (Or build into echo units or something.)

I thought this might come in handy.



>> More food for thought:

Nam June Paik 'Random Access'
http://www.medienkunstnetz.de/works/ran ... /images/3/[/url]

Prepared tape head on Youtube:
http://www.youtube.com/watch?v=YwRf9rih2DIhttp://heregoesnothin.com/sony.jpg

Any ideas? Let's hear it...

[Jeremy Garber]

TP, Do the top and bottom decks have electric motor engagement for the heads? Are they 3 head? If so, any way you feel like tearing them up for a photo op?

BTW, those knobs are an obligatory rip.

[Teacher's Pet]

I'm not sure about motor engagement... Can you explain what you mean exactly?

Here's some more info:

Technics M234X
On top in the previous photo. Can't remember exactly what's wrong with this one.

Realistic SCT-90
On the bottom in the previous photo. I believe this one works fine but plays slow. (Or was it fast?)

Sankyo STD-1750
In the middle of the photo. The coolest (and oldest) of the bunch. It moves tape and makes sound but the sound cuts out after one brief second. And I think there is sound in only one channel. It has 2 1/4" mic inputs and 2 VU meters that move (for a second) and light up. Looks like 2 heads. Biggest knobs ever.

also:
Sony TCWR590
Not pictured, double cassette deck. Again, can't remember exactly, but I do remember it failed the functionality test with flying colors.

But wait, the plot thickens:








I can take some more photos, though probably not today, I haven't got my camera with me.

It would be cool to do this as a group. Everybody get your hands on a cassette deck and a camers, hack 'em apart, upload the results. Though I suppose that if this was really easy and simple, it would have been done by now.

[curtiswyant]

Why does it need to fit in a stompbox? You could use a 3-head cassette/reel deck and a small mixer with no mods, maybe just have a loop pedal on your board to turn the delay signal on/off. Also, if you don't want to mess with a tape speed control, you could always make the playback head moveable via a slider or something like that on the outside of the pedal.

[Jeremy Garber]

I'm not sure about motor engagement... Can you explain what you mean exactly?

On many decks the playback and record buttons are physically attached to levers that push the heads down onto the tape (engagement). On nicer decks the buttons are just electronic switches that, when pressed, start a motor that moves the head(s) down onto the tape. The importance of this is that I don't want to have the heads statically engaged on the tape (always touching the tape even when the effect is bypassed). Using the former mentioned deck, I have no idea how to trigger that mechanical action when the stomp switch is pressed. On the latter deck, it should be a lot easier since stomping the switch would not be much different than pressing a button (both are 'switches' that would activate the motor).

Though I suppose that if this was really easy and simple, it would have been done by now.

So true, so true. Yet, I have such a clear picture of it in my mind. hahah I think the biggest advantage I'm reaching for is the availability of replacement decks from OEM vendors- being able to buy a complete working transport, drop it in, and build the rest of the circuit around it, instead of creating a complete transport from scratch.

Why does it need to fit in a stompbox? You could use a 3-head cassette/reel deck and a small mixer with no mods, maybe just have a loop pedal on your board to turn the delay signal on/off.

Would you not want something like this available in a stomp pedal? Aside the fact that I don't want to be carrying around a tape deck, let alone a reel to reel, and a small mixer, PLUS a loop pedal (and you still need some way to control delay speed, etc) to shows to get this one effect. I'd rather use a regular delay pedal instead of messing with all of that. In addition, I just want this to be a clean execution, self-confined, etc.

I know in my head I'm making it out to be easier than it is. Really, I would be building a modified delay pedal- before the normal delay circuitry (kind of- the delay stuff would be in the feedback loop between playback and record heads) would come the tape transport to color the sound. Since there are transports available as replacement parts, I need to find an enclosure small yet big enough, and mount the transport into the enclosure to prevent damage to it with normal gig use.

Also, if you don't want to mess with a tape speed control, you could always make the playback head moveable via a slider or something like that on the outside of the pedal.

I'm no longer planning on adding a variable speed controller to the motor to control delay. Now I'm thinking I would like to control delay time in the feedback loop with an IC or something. Problem with cassettes, is that the playback/record heads are so close together in 3 head systems that the tape would have to move very, very slow to get longer delay times. At those speeds I imagine the noise to signal ratio would be a problem. I have thought about using a speed control on the motor as more of an added effect than to control delay time (use it to wash out the delays more), but it would need to have a limited controllable range.

[Teacher's Pet]

Apologies, DIY Delay Heads, I was away for a few.

re: motor engagement
It seems most of the tape decks do in fact have motor-engaged heads. The Sankyo does not, it has what I think are called "piano keys" or something like that, where the lever action lifts the heads. I prefer those for the "real time" action.

The Sony deck (not included in the photos I posted previously) had something wrong with the motor engagement, I think. If I remember correctly I had to pry a tape out of the thing.

As far as size goes, maybe it doesn't have to be as small as a foot pedal, but more like Space Echo-sized, with a remote footswitch?

I think all the decks I have are 2-head and not 3-head. Is this a dealbreaker? I suppose that's why one of those other DIY solutions employed 2 separate walkmans. (Walkmen?)

Any other photos or facts I can provide?

- Robin

[newfuturevintage]

I think this:
http://cgi.ebay.com/Sony-3-head-cassett ... dZViewItem
would make a good candidate for this kind of project.

[Jeremy Garber]

What I need to do is Google all the 3head tape decks I can find to figure out which models I'll be looking at. That's my starting point. Then from those decks, narrow it down to the ones that have a motorized head engagement. At that point, I should have a few decks with usable transports, and it will be a matter of finding a replacement parts vendor for those decks so I can buy a transport and start experimenting. I still have a lot of research to do for this project.

I haven't seen what size enclosures are available, but it certainly would be larger than your common stomp box. If it has to be in a box too large to stomp on, I like the idea of a break-out switch box.

Right now I'm working on distortion circuits, so that's where my efforts have been recently. I'll be experimenting with delays soon though, as they are the building blocks for other time modulation FX. I might work on EQ/filters prior to delays.

I just picked up a couple of new books last Saturday. One of them, 'Electronic Components', has been a great resource as it is a little more in depth than the first book I read, 'Basic Electricity'. I'm over half way through it and I've been learning a lot more about constructing circuits from scratch so it will definitely help in this project. Lots of reading been going on- my bookmark list has grown quite large and it has led me into lots of new math stuff that is frying my brain at the moment.

[neaimepas]

I delved into a project like this once, but so much static from bad wiring made me want to turn it into a fuzz box instead, in the end it was easiest to make into a massive box that sat ontop of my amp or something, and i made a switch pedal to put on my pedal board,
I've made so much useless crap (and lost enough of it also) that I couldn't even begin to remember how I did it.
But I do have a piece of advice......
Don't get locked into the image you had in your mind at the beginning. Some beautiful things will happen when you forget the books and go for gold.
kind of a general comment, but its all i have to offer.
it seems like an awesome project so best of luck mate!