Real Tape Echo

[AdamB]

Been working on this one for a while, just about done with it now. I'll be releasing the STLs and PCB files and a how-to video for this in the next few weeks so look out for that.

Hackaday project is here:
https://hackaday.io/project/181052

Original thread is over here:
https://www.diystompboxes.com/smfforum/index.php?topic=126251.0

[theehman]

That's very cool!  Looking forward to the info!

[vigilante397]

Great looking project, nicely done I had ambitions for a while to build a tape delay, but I recently found a killer deal on a used Trex Replicator, so I no longer have such ambitions

[theehman]

Yeah, this is really a neat project.  I can't wait to build one for myself.
If only someone could build one that would use standard cassettes.  That would be a great way to use all the crappy tapes laying around.

[noisette]

Yeah, this is really a neat project.  I can't wait to build one for myself.

This is really something I´ve been waiting for since long time, I love it!

[Mark Hammer]

Total length of tape?
Type/thickness of tape used?

[Kipper4]

Cool project.

[AdamB]

Great looking project, nicely done I had ambitions for a while to build a tape delay, but I recently found a killer deal on a used Trex Replicator, so I no longer have such ambitions

I have the replicator Jr. It's a real nice unit - I don't take it out to shows though because I'm afraid of breaking it. It's probably fine for a lot of bands, but we're a DIY punk band and our shows get somewhat "aggressive" : With this machine, when I break it, it's cheap and "easy" to fix - the parts most likely to break can be 3D printed and the tape machines it's built around are cheap (about 25 UK pounds) and available enough that I can keep a few spares in storage.

Also, the replicator suffers from that issue where the tape doesn't clear down when you deactivate the unit - so if you're screaming through it when you turn it off, that's what you'll get a blast of when you turn it back on, which is not so good for live use where I can't think about that in the moment. I've solved that issue with these by having a "clear down" mode you can toggle in the firmware. Essentially, when you deactivate the effect, it'll run the motor for a few more seconds to pass all the tape under the erase head to make sure it's cleared down for the next time you want to use the effect. Obviously if you turn it back on again straight away you still get the problem, but for 95% of times it gets rid of the issue because a couple seconds will have passed since you last used the effect. I used the replicator a lot on our last EP as outboard, though. Very happy with it.

If only someone could build one that would use standard cassettes.  That would be a great way to use all the crappy tapes laying around.

I tried going that route initially - the issue is that with a standard cassette, if you're using easy-to-find cheap heads, there's nowhere to stick all 3 (erase, record, playback) and use a pinch roller at the same time. I actually designed a 3D printed pinch roller mechanism with motor mount and pulleys and what not (I think there's some info on that on the hackaday page) - the eventual goal is to ditch the portable cassette player entirely and 3D print the entire transport. It's definitely possible, I think I proved that with the prototyping I did, but it still means you can't use cassettes. I just don't have time right now to dig into that, and tbh it's easier for people to make these themselves using an already-built transport. So long as people can source that machine (which currently they're all over Amazon), then people should be able to "easily" reproduce what I've done.

Total length of tape?
Type/thickness of tape used?

I used "Cliff Richards private collection". So whatever tape that was made with 
https://www.instagram.com/p/CRcOSbjJPDx/

As for the length, I'm not sure - I'll have to cut a loop and measure it. I tend to just feed the tape through the transport then cut the ends and tape it up, rather than measure it out first. I'm currently building one for the bands bass player as a demo for the "how-to-make-this-thing" guide, so I'll measure the loop on that one when I get to it and report back.

[anotherjim]

..." clear down" mode you can toggle in the firmware. Essentially, when you deactivate the effect, it'll run the motor for a few more seconds to pass all the tape under the erase head to make sure it's cleared down for the next time you want to use the effect.

Genius!

I used "Cliff Richards private collection"

Can't get cleaner tape than that. Absolutely pristine virgin condition.

[Mark Hammer]

I asked about the tape because some tape is more geared towards high use, other towards long-term storage, and so on.  Cassette tape of the 1/8" variety was never really geared towards either of those, if only because a cassette cannot contain a lot of tape.  All those cartridges with commercials that DJs would slap into the player were the size of 8-tracks, and used 1/4" tape.  They didn't have to be long - maybe 30 seconds of play at most - but the assumption was they would have to be played hundreds of times in a week and so had to stand up to wear; likely 1.5mil, whch is several times thicker than what music cassettes employ.

Not a slag, just a reality that may require more regular change-of-tape than might be true of a tape delay using thicker 1/4" tape.

[AdamB]

I asked about the tape because some tape is more geared towards high use, other towards long-term storage, and so on.

Sure - tbh I just went with cassette tape because it's very easy to get hold of both tapes and machines; our bass player turned up to practice a few weeks back with a carrier bag full to the brim with cassette tapes that he got at a boot sale for £1. And there's lots of availability of heads for machines like this, too. I don't know enough about more "pro" tape machines to really do anything more clever than that. Perhaps someone will take my design and upgrade it to fancier tape for better performance/reliability. It's all going to be open-source so people can take what I've done and take it a bit further if they want to.

[Mark Hammer]

No worries.  If you can find C-15 cassettes that one might use for old school (e.g., Commodore 64, VIC-20, Acorn Atom, Sinclair ZX-80) cassette storage of computer programs, that stuff might be thicker and stand up to more abuse.

[AdamB]

If you can find C-15 cassettes that one might use for old school (e.g., Commodore 64, VIC-20, Acorn Atom, Sinclair ZX-80) cassette storage of computer programs, that stuff might be thicker and stand up to more abuse.

That's good to know. I have a couple of C-10 computer cassettes (if you look closely you can see the reels in this machine are taken from one ), I didn't realise they were made with thicker tape. I'll take a look and see how it compares when I build the next unit.

[Mark Hammer]

It's not a given that they WILL be thicker tape, but you can check with your fingers to feel if the tape does seem thicker and stiffer.  Sometimes, it's not a matter of the intended purpose of the cassette, but rather simply how much tape one can fit in there...which is itself loosely correlated with purpose.  So, a 90-minute music cassette is not going to be able to fit in the cartridge if it uses thicker tape.

The thickness of the tape is largely a function of the acetate backing on which the magnetizable material is laid down, and does not presume a thicker layer of ferric oxide, chromium dioxide, or whatever.  But that said, thicker acetate means less print-through between concentric layers, and also means less risk of tape-stretching.

[pinkjimiphoton]

I asked about the tape because some tape is more geared towards high use, other towards long-term storage, and so on.  Cassette tape of the 1/8" variety was never really geared towards either of those, if only because a cassette cannot contain a lot of tape.  All those cartridges with commercials that DJs would slap into the player were the size of 8-tracks, and used 1/4" tape.  They didn't have to be long - maybe 30 seconds of play at most - but the assumption was they would have to be played hundreds of times in a week and so had to stand up to wear; likely 1.5mil, whch is several times thicker than what music cassettes employ.

Not a slag, just a reality that may require more regular change-of-tape than might be true of a tape delay using thicker 1/4" tape.

ahh, the trusty PSA cartridge

i used to buy 'em up cheap for spare tape for my echoplex

they work in my kastam tape echo too