Today I have a simpler video for you.
Simple?
On this channel?
Sounds unpossible.
I know right!
But really it’s pretty simple!
Yeah right, let’s just take a quick peek at …
oh.
[if you're on mobile it says 9:32 because who cares about consistency across the platform?]
I guess it is pretty simple.
Yep, told ya so!
I am in fact capable of making shorter videos.
Well this gag sure isn’t helping with that.
Indeed so let’s introduce the topic and
talk about these little cassette adapter thingies.
If you have an older car which only has a
cassette deck but you need your sweet sweet
AUX JACK,
well you’ll probably have used one of
these before.
And they’ve been around for quite a while.
Back when a CD Walkman was the height of sophistication,
you could modernize your car with one of these
and be enjoying the best the world of Compact Disc has to offer.
Ever wonder how they work?
Only all the time!
No!
Stop.
That gag is over.
To understand how this works, we first need
to understand a bit about the technology behind
audio tape.
Fricken’ tapes.
How do they work?
Magnets!
Magnetic tape is some pretty neat stuff, though
it’s not groovy I’ll tell you that.
Instead it’s particular.
Conventional type I audio tape is simply a
thin ribbon of plastic backing which has a
bunch of finely ground-up rust smeared all
over it.
The iron oxide particles can be magnetized
with a little help from an electromagnet.
Inside a cassette deck (or really any tape
deck at all), a special electromagnet called
the head makes contact with the tape as it
travels past it.
Fun fact!
In video tape, the heads do the traveling!
I made a video waaaaay long ago about that
if you’re interested.
Now, because the tape is made of fine particles,
different spots along its length can be magnetized
to different extents.
Think of it like a bunch of teeny tiny bits of metal that can more or less be individually magnetized.
If you move this granular tape across the
head as it gets all electromagnety,
you will end up with a linear representation of how
intense the magnetic field the head created
was over time.
Spots that were exposed to a strong field
will be strongly magnetized, and spots that
weren’t exposed will be hardly magnetized
at all.
Tie that magnetization level to some sort
of signal,
like perhaps audio,
and you will end up with that signal represented on the
tape.
Check out this neat video from Techmoan if
you want to see what that signal actually looks like.
The thing about electromagnets though is that
they work backwards, too!
When a pre-recorded tape, complete with signals
already on it, is run past the same head,
the head can detect the signal!
The changes in the magnetic field the head
encounters as the magnetized tape travels
past it induces a small current in its tiny
little coils.
Even though it’s just a bunch of tiny magnetized
particles, it has the same effect as moving
a magnet past a coil of wire and will thus
induce a current in that coil.
This can be amplified to recreate the original
signal, and thus sound,
that was imparted on the tape when it was recorded.
But of course, these adapters don’t have any
tape in them.
Wait, do they?
No.
No they don’t.
So what do they have?
Well, for a start, an absurd number of incongruous
logos that don’t belong anywhere near this thing.
Like, these are hilarious.
Compact Disc?
MiniDisc?
Pfft.
I like that the DCC logo is on here because
you could kind of argue that it is a digital
compact cassette so long as it’s plugged
into like a CD player or whatever.
Anyway...
First consider what this does.
It needs to produce the same effect as a real
tape - so it needs to induce a current based
on an audio signal in the playback head of
whatever cassette player you’re using it in -
but without actual tape.
How could you go about doing that?
Well, remember that it’s the same head in
most cassette decks that does the recording
as the playing back.
The same head can be used as an electromagnet
to record onto a tape or as a pickup coil
(or magnetic microphone if you will) to play
a tape back.
And so, take a look at where the tape should
be and you’ll find…
a tape head!
A cassette adaptor like this uses a tape head
just like the one in your cassette player,
and when it’s loaded in a cassette deck
the two heads get real personal with one another.
The signal coming from the audio jack is pumped
into that head, which is essentially coupled
with the other, and the end result is that
the audio signal from your phone, iPod, or whatever
is injected right into the other
head and thus into amplification circuitry
of the cassette deck so it can play through
your ‘96 Civic’s stereo or whatever.
It’s that simple!
Ah, but it’s not quite *so* simple.
You see, many cassette decks have some sort
of auto stop feature which works by detecting
that the supply spool has stopped.
Since there’s no actual tape in here at
all, the supply spool wouldn’t turn on its own
and the tape player would just… repeatedly
stop thinking it had reached the end of the tape.
So, these usually contain a mechanism to cause
the supply spool to turn with the take-up spool
(the latter of which is turned by the
cassette player itself)
to prevent this from happening.
Some models will also prevent the reels from
turning backwards, forcing an auto-reverse
deck into the forward position and ensuring
the playback heads align with the little
broadcast heads, if you will, of the adapter.
And is it really so simple as a playback head
wired to an audio jack?
Wouldn’t there need to be some sort of circuit
in there to make the signal from the audio jack…
work?
Well, let’s find out by taking this apart.
It turns out that yep.
It literally is that simple.
Just the wires from the jack going right to
the head.
Now, this head might be designed specifically
for this purpose, though I kinda doubt it,
but I suppose it is possible.
Since the same head can record and play on
a typical cassette deck,
could this be used in reverse?
What if I plugged this into an audio recorder,
and hit record on this guy and fed a signal into it?
Would it be detectable by the audio recorder?
Turns out, yes!
Since the tape bias signal is well outside
the audible range
it doesn’t seem to affect things too much and you do in fact get a signal
out of the cassette adapter.
[tinny music is heard]
While this is completely and totally useless,
it is at least mildly interesting.
You might be surprised at the audio fidelity
these things are capable of when used in the
more normal fashion.
For one thing, there is no tape noise at all when
you use these.
That hiss you hear from a tape is a result of the random structure of the magnetic particles themselves.
You can’t get rid of it unless you use some
clever tricks like Dolby Noise Reduction,
and even then it will still always be there
a little bit.
But if you don’t have any tape, well there’s
no tape noise!
Seriously, to my ears using one of these,
even a really terrible one like this, is basically
indistinguishable from a legitimate auxiliary
input.
It’s pretty remarkable.
Oh and by the way, if you use these you want
to make sure Dolby noise reduction is turned
off as otherwise you’re getting a needless
reduction in fidelity in the form of a rather
pronounced treble cut.
And of course, for one last fun tidbit, since
electronics keep getting smaller and cheaper
we now have Bluetooth versions of these!
These are actually really neat, they have
a small battery with a micro USB port to recharge it,
and a module inside allows you to pair
your phone with it so you can play music through
its little integrated head.
They even give you a little microphone on
a dongle for making hands-free calls.
I have no idea how well that part of it works
but for $15 this thing is pretty neat.
I remember seeing in the past that someone
had put out an MP3 player inside one of these
cassette shells complete with transport control buttons and its own headphone jack,
giving you hipster cred when you needed it and actually being useful in older cars.
I tried looking for it again but “cassette MP3 adapter” is a woefully unspecific term these days so…
well it’s probably still a thing but personally these Bluetooth ones which you can find in stores now
would be my preference as they’re actually quite capable of modernizing an otherwise old car.
Well, that’s it!
Can you believe it?
A reasonably short video from Technology Connections!
I feel like I must be dreaming.
Anyway, time to leave you with everyone’s
favorite smooth jazz hit.
I…
I can’t find the boombox I wanted for this
shot so you know,
just pretend.
[mechanical clacking from the tape deck as music comes it quitely]
It’s kinda loud.
♫ simply smooth jazz ♫
...but you need your sweet, sweet aux jack…
mm … that didn’t go well.
Conventional type I audio tape, which this
is not, is simply a thin ribbon of plastic
… yeah I should get a type I tape.
Shouldn’t I‽
We can’t…. we can’t use this chrome
tape because you pedants would be like
“that’s a Maxell XLII! 
That’s not type I tape!”
so, gotta change it!
...and talk about these little cassette adapter
thingies…
hoo that was a bad…
My nose itched.
Probably a fine take.
...range it doesn't’ seem to affect things too much and you do in fact get a signal this is really rattly
That magnetization level to some so…
Aagh!
Tie!
That was the word, tie!
I was like “tie? That doesn't make any sense!”
No, you wrote that word.
I cannot tell you how relieved I was that the video actually shows as 9:31 long here in the player.
BUT ONLY ON DESKTOP! In the video manager, mobile, (and probably on the home screen) it says it's 9:32.
So you just can't win.
Anyway bye.
[this caption intentionally left blank]
