[audio cassette player] Are both or only one "axis" supposed to drive the tape?
I finally bought myself and old audio cassette player. The insides look crazy clean and the drive belts seem neither loose nor dried out.
But!
It's only the left "axis" - or whatever it's called - that's spinning and thus "driving/forwarding" the tape. With "left", I mean the one that rolls up the tape as it's being played. Looking inside, the right axis is not even actuated. It's just a "dead"/unmoving part. Is this how they all work?
24 replies
yes, it's used to rewind, not play.
Only one of the spindles will be active at a time, the one collecting the tape from the other, if the player has an auto reverse mechanism it'll switch between them, if not, it'll just be the one
If you were curious, there's also a capstan and pinch roller that you won't be able to see that is responsible for holding the tape onto the tape head and moving it along, so it's not tension from the collecting spindle that is dragging the tape through everything.
Crazy word. "Capstan". I'll read up on it! Thanks! 😃
I think the word originally comes from boats if I'm not mistaken!
That was it exactly! Just looked it up! Crazy physics going on there too! :D
I don't have a cassette player around, but I'd think that it'd be extremely difficult to have a motor drive the unspooling side concurrently, because the ratio at which you'd need to drive the two gears would change over the span of the tape due to the size of each spooled-up tape radius changing. And tapes aren't standardized in length, so it's not like the tape player—even if it had a way to know where it was in a tape when you inserted it, which it doesn't—would really have a way of knowing that ratio.
Sic! I had never thought of that! Does the winding/spooling speed of the driving side change to account for the change in radius?! How is that solved mechanically? Pressure plates that "feel" the size of the spool? 🤯 Or is that just the case if it had two drives?
There's no need to fix it since the tape is recorded the same way it's played.
Like a vinyl record, the grooves towards the outside of the platter are moving faster than the grooves on the inside yet it spins at a constant RPM.
One advantage of analog is that there's no constant "bitrate" that has to be maintained though faster moving analog media generally translates to higher fidelity.
Whoa
This is a whole new world to me. I can't wait to deep dive! 😍 Thanks again!
So, I guess that that means that the fidelity of audio near the end of the cassette would be higher than that near the beginning. Huh. Never thought about that. Neat!
Yes. In very rare cases, vinyl records will be cut with tracks running inside to outside. In the one example I've seen, it's to accommodate the building crescendo of the classical piece recorded. The louder more dynamic portion at the end benefits from the faster vinyl.
https://m.youtube.com/watch?v=5Afikv6k1-c
Edison's original phonograph used cylinders which offer constant speed playback.
I had one where the feeding spindle was smooth and fixed.
The only reasons to have the feeding spindle grip the gear and move is to rewind the tape and/or collect the tape in auto-reversing decks.
Many portable players didn't have rewind/auto-reverse fir cost reasons, so the feeding spindle would be just a fixed pin.
So, why not get rid of it? Well, to prevent the feeding roll from wobbling and causing jams or damage to the cassete or tape.
I always called them spindles or gears.
Anyway, you can test this by running it without a cassette in it. As others have pointed out, one side pulls and the other is idle.
I kinda miss tapes. K-Pop groups still release them. They are not cheap.
I just ordered three supposedly factory sealed Cyndi Lauper tapes, just to see if "new" tapes sound at all better than the ABBA tapes that my dad found in the cellar the other day.
If only one drives the take it won't rewind. For rewinding the A side you have flip the tape and go full forward on the other side. If both sides have "traction" you can reverse and go firward freely.
Yes.
But you're holding it upside down. Normally the right one pulls the tape through the head. The logic goes that it reduces the number of components in the build, and if there is a problem you don't want the trailing spool continuing to push tape into the mechanism.In an auto reverse deck the active one will stop and the idle one will start. That pulls the tape through in the opposite direction to read the second track. In a normal deck you'd flip the tape around because it only pulls in one direction.
Edited: I looked at the pic and saw that your tape goes in upside down.
Ah, thanks for the clarification! 🥰 Yeah, the tapes go in upsidedown. 🙃
Like for playing the other side in an "auto reverse" deck, the other axis should be engaged in your tape drive if you rewind the tape.
I don't think this one has a rewind function. 🫣
Oh, I didn't know these exist. Even my Walkman from back in the days (mid 90s) has one.
This one has three buttons: play, fast forward and stop. Maybe some button combination is rewind? I'll check the manual tomorrow. 😊
It's been a long time since I used one of these. But back in the day I had multiple 'walkman' style cassette players (one Sony, one Pioneer, one JVC, and over it two others I think). And from what I recall, they almost all only drove from one of the two spindles.