New tape echo just finished up

Just finished up this compact delay. Nothing especially out there, dry/gain/wet/feedback/motor speed.


Hmm, sounds interesting. I’ve been saving tape recorder heads and such for a while to make a tape delay some day. Can you provide some more details / pics etc?

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Finishing up this one right now. This has been much easier than trying to cram everything into a compact enclosure.

Ive only recently started messing with them


Looks nice! Any sound demos we can listen to?

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You gotta look at it like 4 or 5 seperate things. Your dry, input/gain, a mixer, (doesnt have to be fancy, four signals coupled.), a record head w/circuit + motor, a playback head, (can just be wired to a simple preamp circuit) but, the playhead is mounted in your record heads deck. Feedback signal starts at the record line in. The outpout of the playback is you wet signal. I could draw up a schemy of the gist, if you’d like

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I have to put insulation between the mounted components, and the metal enclosure, then make sure it all sounds good. Its seems to be working fine, just needs some finishing touches.

I’m not really familiar with the electronics behing tape decks, but I’ve heard that biasing the signal (mixing in some kind of AC-signal?) was used to get better recordings. So I assume you use the original recording electronics. But what about using multiple play heads? What circuit do you use to amplify / pick up the signal from the extra play head?


You could use the other cassette recorder, if you got the head from one or, just make/buy a simple one channel preamp. Head goes to in out goes into thd mix

There’s a frequency bias between the erase and record heads. Thats why dialing up the feedback pot causes the tone to get brighter and the number of repeats to increase until the echos begin oscillating with each other. Im guessing the erase’ magnetic field, wiping the reel while the feedback loop from wet to record and getting picked up again by the wet/play head. With the erase head returning the reel to something like a blank carrier wave while sound is still echoing does something. Im confusing myself a bit now but, i think thats the general idea

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I tryied a long time ago in the 90s with a LEGO® frame. But the electronics failed me and the sound was very noisy.
I had a couple of echo since then, copycat, se500 and some other. All of them broken and I had to repair them. This was not an easy task. As a lot of things are involved, mechanic noise, magnetic noise, bad capacitors noise, dirty head noise…
So now I modify digital delay to suit my needs… :smiling_imp:

Ya, coupling was a problem, ground loop, input signal was barely audible. I added another preamp between the in jack and the dry/gain signals pots 3. Wet and drys wiper each just went to their own 10ks that met at output. Gain wiper was 10k to 1uF+, the neg met another -1uF where rec circuit mic+ line also joined. 1uF Pos side met 22nF(one leg to gnd) then to 1k where feedback wiper was. Playback out+, feedback pot3, wet pot 3 all meet up, wet2 is the “bridge”

Get two different length garden hoses. Speaker at one end of the two, mic and the other. Boom DELAY. Have you seen floppy drive delays?

Yeah, no I did’nt know the floppy delay. I dreamt about it when I was younger. I just saw a demo and it could have been a little wilder.
THere is also the “midfi clari(not)”. It’s a PT2399 driven by a photocell. The initial purpose is that the delay time changes with the strengh of the signal but it can be something more just with an oscillator or any type of signal applyied on the LED. Could be a great module by the way.

Midfi electronics? The clarinot sounds familiar. I think the sequencer that spins a disc over an array of photocells with little slits cut out around the plate is pretty cool. I gotta switch it up fot a bit… finish my guitar, ive got one of those old chinese keyboards i want to mod out as well. I’ll have to look into using photocells with pt2399s, that sounds cool. Thanks for the tip my man.

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that reminds me of that


Ever make a tremolo with windex?

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Ya midfi is my buddy doug. Cool ass dude, very cool pedals. I knew the clari(not) sounded extremely familiar.

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yes ! maybe it was my first diy build :wink:


Looks so good, I think I’ve seen that one before.
I have so many tape parts, and large sheets of abs, plexi, wood, (along with the tools), I am going to start building them similarly.