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TAPE DELAY-AY-AY-AY


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Guest Symatic

So Jamburglar asked me to start a thread on this nerdy but awesome effect.

 

basically my obsession with tape delay went from "i've always loved that sound" to "I need to put tape delay onto everything in the world" when Rockwell gave me his dad's old Akai reel to reel deck.

 

The Idea was to copy Cutmandoo's tape scratching technique (who we also happened to see live that weekend at CSBBQ) but I chatted to him at the BBQ and he said you needed a specific deck (which I eventually got but thats a different nerd story...) anyway the akai wasn't gonna work for that but Matt gave it to me anyway and when I got it home I learned about it on youtube from some kid that did all sorts of mad experiments on his one, including getting images stored as audio on tape (!!)

 

Turns out that the Akai 4000DS has the right features for tape delay: it is a 3-Head tape deck, so the tape passes 3 heads in the transport:

 

an erase head - a magnet that fires really loud really high frequency electromagnetism at the tape when the deck is in record mode, erasing anything already on the tape

 

a record head - a magnet that converts audio signal into magnetic field, the intensity of this field gets imprinted onto the magnetic material on the tape (essentially sellotape with rusty dust on it) and as the tape passes it provides a continuous recording like a record groove.

 

a playback head - a magnet that does the reverse of the record head, reading the fluctuating magnetic field left on the tape rolling by, and converts this to electrical energy to be sent through amps and stuff onto your speakers.

 

 

the other thing the Akai has is a Monitor Selector that allows you to monitor the playback head whilst you are recording - and here's the trick:

 

you set the deck to monitor the Play head, and this head is a few centimeters AFTER the record head, so that gap between the signal getting recorded and played back is what creates the Delay.

 

then you have to create a feedback loop in the audio path - to do this you send you need a mixer with multiple outputs and inputs. I use a Allen & Heath Xone02, which has Aux Send. So I could play a record on channel A of the mixer, then send the audio out of Aux and into the Tape Deck's input. The signal then goes through the tape deck, out" of the record head, onto tape, the tape moves over to the playback head, and the signal goes back "in" to the tape deck, and out of the Tape Deck's output (because you set it to monitor the playback head). Then the signal comes into channel B of my mixer (where I can EQ it a little if theres too much bass/treble....) and that's where the feedback loop is completed, becasue the signal is then ALSO going to the Aux output that we originally sent the audio out of, and the whole process gets repeated for as long or as loud as you want to set your Aux output.

 

here's an old vid of me playing with it. I'm using 2 mixers, one for mixing records, which also has a send/return, and this send return is going to my Xone02 which is dedicated to being a feedback loop for the Tape Delay. (if I just used the Send/Return i'd only get one delay because it doesn't feedback)

 

 

 

I actually realised recently that I can not use the 2nd Mixer, by creating the feedback loop using the Akai's built in headphone output and mic inputs - this only works because the deck is so old that it doesnt have the more modern invention of automatically disabling audio from Line In/Out when you plug in a headphone or mic jack. the problem with this technique is that it doesn't allow you to EQ the sound, which gets kinda out of control sometimes as different frequencies get amplified and take over the swell of the effect.

 

anyway, it sounds awesome, and even though that deck can't change speeds on the fly, the speed it does happens to work on most dub tempos as a triplet, and most hip hop tempos as a straight half-beat.

Fancier decks with more features mean you can do more stuff, like theres Sony decks that have "echo" mode so you dont need extra mixers and stuff, and some decks allow you to change speeds while the deck is running in record mode (others either dont have speed options at all, and many disable pitch controls during record mode to prevent people recording at the wrong speed...)

 

 

So recently I have been working on a giggable (ie protable) setup as the akai, while sounding amazing, isnt that portable and really needs a 2nd mixer to get the most out of it. I've done gigs before with it and its totally worth the ballache, but it is a ballache.

 

So I found one of these Marantz decks on ebay (I searched for the CP-430 not the PMD-430, they are exactly the same but PMD is the famous one that got sold in the US, the CP version is european and often goes for less than £100, theres one on ebay now) and it has pitch control, 3 heads and is famously good quality.

I had to mod it slightly to allow pitch control during record mode (this was a very easy mod if you can solder) but the pitch control is limited to about +/- 6%. I am hoping one day someone (aka rasteri :) ) will figure out how to take control of this pitch range and extend it to =/- silly%.

The reason I wanna do this is, as you can hear in the video, the delay time is very short, because the tape heads are physically closer and the tape travels at a relatively faster speed on a cassette.

 

 

Still, its a dope deck, and other models like the PMD221 are commonly modded to be delay units, a guy makes them as a small-batch product called the Space Case but they are pricey.

 

So the other day I saw one of these Sony decks on ebay for a reasonable price, and even though its only mono, it is still very dope, and has all the right features, but intrestingly has a longer delay time due to wider head spacing, and also a really unique feature - a Bucket Brigade Device. This is what most delay pedals use, its a chip that basically uses electronics to slow the audio down by passing it through a stupidly long signal path. the reason this deck has one is for Voice Activated Record Mode, so the idea is that you speak into it, it records to the BBD, giving the motor time to kick in, then the BBD writes to tape. For my purposes this functions as a way of adding delay time which is awesome.

in fact I learned all about that from this youtube video where someone was doing exactly that:

 

 

 

so anyway, tape delay sounds awesome, reel to reel is best because the bigger tapes mean better quality and you can also prod and poke the reels to get cool stuttering effects.

cassette doesnt sound quite as nice but has its own character and is more portable.

all tape delay has a certain quality to it that has never been replicated by digital effects, and even the fancy plugins you can get don't seem to do it justice and they all cost enough to make me think the real thing is the best thing.

 

So that's my geeky roundup of tape delay, hope you liked it, Jam :)

 

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Man, that's dope.

 

The main reason I want it is for longer delay times but it sounds like the delay time is always gonna be fixed by the physical space between the heads. I have a Rockman Stereo Echo, which is a 1/2 rack size analog delay. It's not tape delay, but uses a series of bucket brigade chips. https://www.rockman.fr/Reviews/SE.htm. It's the only analog, stereo in/stereo out delay I've ever seen. The only downside is that its limited to 500ms of delay, which is nothing to sneeze at, but my digital delay spoils me with these really lone delay times and sometimes I want that.

 

I'm kind of surprised they didn't have more analog tape delay options with movable heads and stuff like that. Sounds like lots of DIY out there.

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Guest Symatic

yeah thats another way of doing it, matt, i've seen people doing it with twin deck machines with bits ripped out and 2 cassettes modded to share one bit of tape

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Guest Symatic

yeah Jam, the other ones to look for are the CopyCat and obviously Space Echo and variants. the copy cats are affordable (as in, in the hundreds of £s) and space echo's are silly money and everyone i know with one can't seem to fix it :)

 

for people more electronically gifted than me, i imagine it would be possible to bastardise a tape deck so you could change speeds more easily. the sony deck I just bought looks like it has a similar switch circuit to the maranatz so i'm hoping i can mod it in the same way and use its existing -20% +40% pitch control.

 

I wish I know more about electronics cos I'd love to build a dedicated unit. you could have a tape loop in there, and all the mixing, eq and feedback circuitry inside, a pitch control for the motor and also a sliding playback head. the pitch control would also control time but the sliding head would control time without affecting pitch.

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Space Echos must have picked up in price because not too long ago they were affordable. If I remember right D-Styles sold his on e-Bay for a few hundo.

 

 

Yeah they are like £1200-£1500 now i think

 

 

Fuck that, I'll just get my friend to come over say "Fresh, fresh, fresh, fresh." into my mic in. Totally analog.

Sold my old Roland SE 201 in the early 90's and regretted it ever since.

 

I've now come to realise I was a massive cock end back then.

 

Top thread though Sy.

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Ah damn dan.... yeah these things come and go dont they.

 

I have a super pro tape deck too, my current work threw it out. Its a revox c280, which is one of the last ones they made, and it has a timecode card in it which in theory lets me sync the motor to a DAW. They threw it cos it wasnt working and was out of date. I managed to get it working but it doesnt play out of one channel.

 

But i did test it by recording a track onto it and back off again, and lined the (single channel) audio up with the original and it was exactly the same. Sounded perfect and no drifting... thats withOUT the timecode :) so the things pretty sick basically, and it has plus minus 30% pitch so coukd make a ridiculous tape delay whilst serving as a functional studio bit of kit

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I uploaded this to my channel a year ago.

 

https://youtu.be/4g4WfNiGNxg

 

I love delays and as I can’t afford none truly analog I mess with monotron delay. There is also a space echo pedal more affordable than the og units. All of those digital but cheap for weirdness ness ness ness...

I came to this from live looping and dub research so I want to share some interesting things I found over time.

 

 

 

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nice one mutis!

 

yeah monotron is a lot of fun for not much money, and the space echo pedal is indeed excellent, I own a monotron and half-own a space echo pedal with my mate

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This is way cool. I love dub and so of course love some heavy tape delay too. Ive tried to mimic it with other gear but nothing is quite the same as you know.

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Slightly off topic, any ideas what the oldest audio affect is ? Just for nerdy reference.

 

i guess reverse? i read some old article about victorian era people listening to phonographs backwards and describing the sound of a reverse bell. imagine being the fist people to hear backwards sound :)

 

but i have no idea..... but reverse is my best guess. and off speed playback i guess

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Guest Symatic

 

copicat's are available on ebay for like £250-£350.... theyre really nice, my friend had one on loan for a while, but they are just mono. the nice thing about (mis)using a reel to reel tape deck is that the device (heads, amp etc) is all designed for line level full range music, rather than mono signal or just designed around instruments like guitar, which can sometimes mean whole chunks of the frequency spectrum are missed out....


my ultimate dream would be to have a little portable nagra tape deck as a delay.... but theyre like thousands of pounds :)

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  • 3 weeks later...
Guest Symatic

random update

 

I got my new Sony cassette delay up and running - finally!

 

I had to order the deck from america, then get a relative to smuggle it in their luggage to avoid customs pay lots in customs fees which i'm totally happy to do, especially when our own government and royalty set such a great example.
I ended up getting some money off the deck cos it was advertised as "excellent working condition" but actually the belts were all fucked so it didn't run very well. but the ebay seller was cool, and gave me enough money off to pay for the new belts.

so i got the belts, took the bastard apart, had to desolder all sorts of bits just to get into the mechanism.... damn it was a pain in the tits!
eventually got the belts fixed, and put it back together.... then had the annoying problem where a feature of the deck had gone haywire. it has a beep that comes on when it tihnks the tape is about to run out - i guess it works this out based on tape tension or something.... anyway, it would come on all the time, and beep at me while i was trying to do delays, so it would be like having a king tubby style test tone coming in and out all the time, but it got really annoying so I spent fucking ages staring at the schematic trying to understand what the fuck i was looking at, and trying kinda random stuff. I removed stuff that looked like it was related to that part of the circuit... but normally ended up making the deck un-usable entirely, so had to put it all back as it was.....
eventually i found some wires that went to the little board near the mechanism that seemed to measure whatever it was that the alarm needed to know whether to beep or not.... i tried removing all these wires so the information never got to the alarm.... but this just made it come on permanantly... aargh!

BUT, when i put all this back together, it seemed to fix it - i guess one of those solder joints was just dry and fucking with the signal, and me re-soldering it made the system work properly again.

 

I also found a part of the circuit that looked like the switch which disengaged the speed control and tone control while in record mode - which is what i need to do different speeds of delay rather than just having one set speed.

I shorted out the pins on this switch so it was permanantly set to it's PLAY position, and cut the trace for its RECORD position, so now i can control the speed of the tape whilst doing delays which is really cool.
unfortunately trying the same trick with the tone control caused some sort of feedback loop, so i had to put that back to its original setup.... maybe one day ill figure that out. it would be really nice cos then i could shape the sounds that get delayed - which get more distorted as they trail out, so can get kinda intense especially at the higher frequencies, so being able to kinda filter them would be ace.

 

anyway.... right now its working, and is really fun to use.

I've got to work out why the motor seems to generate a bit of buzz in the signal - i think it might just be the sound of this deck (its an old unit for recording interviews and stuff ) but if theres some clever shielding i could to to keep it quieter i't would make me a lot happier about playing out with the thing.

 

I'll poast a vid soon! here's some pics though:

 

Oh yeah - theres a infinite loop tape in there too, which i ordered online for a few quid.

 

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