Cassette player modifications?

[theworldisawarfilm]

 Recently acquired an old Califone tape recorder similar to the American Library of Congress units which, besides having 8 separate outputs and an auxiliary input, also has  a variable speed control. What I am curious about is getting said speed to control to go slower than it does now. It seems to have much more "headroom" for speeding things up (not something I'm interested in. There is already a ffwd for that) and less for slowing the tape down, if that makes sense. Wondering if it would be possible to extend that "headroom" and have maximum slowness? Can solder just fine, but pretty ignorant of "theory" behind electronics construction/repair/modification. Any input appreciated.

If there are people here who use tape extensively, I guess it might be fun to share other modifications/knowledge of tape units here as well.  Cheers.

[Theodore]

Don't know about these units, nor much in general. What i would try to do ? Does its motor have a little hole on the back ? To slow it or speed it up.

Briefly, i would slow the motor down, so with speed control in the middle be slower than normal, then find at which faster control's position is the normal speed. That way probably you can have maximum slowness if you set it the normal speed be at control's fastest position.
Not sure how / if reel motor will be affected though. If it will behave well to have good transportation with the new extreme settings. I think it will be fine but you will see that in action ...

You need a 3KHz test-tape and frequency meter -if you need to set the normal speed- . Use a ceramic screwdriver to set the motor's speed, or cover it with tape -not its tip- .

[theworldisawarfilm]

Don't know about these units, nor much in general. What i would try to do ? Does its motor have a little hole on the back ? To slow it or speed it up.

Briefly, i would slow the motor down, so with speed control in the middle be slower than normal, then find at which faster control's position is the normal speed. That way probably you can have maximum slowness if you set it the normal speed be at control's fastest position.
Not sure how / if reel motor will be affected though. If it will behave well to have good transportation with the new extreme settings. I think it will be fine but you will see that in action ...

You need a 3KHz test-tape and frequency meter -if you need to set the normal speed- . Use a ceramic screwdriver to set the motor's speed, or cover it with tape -not its tip- .

Thanks I might give this a shot in the future with another machine I've got.

Honestly, I feel dumb for not just trying this off the bat, but a less invasive workaround...record tapes at half speed. Duh.

[Theodore]

That way you actually need to record tapes at fastest speed, knob far right. Then on playback of these tapes the normal speed will be with the knob at the same fastest position, and every other position will play them slower, so you will have the maximum slowness headroom.

Hope i got it right. Just woke up, i am not in full speed yet haha. Think about it.

[Cementimental]

I've had some success adding speed control to tape decks by simply buying cheap little pre-made DC motor speed control circuit boards on eBay. They have a control knob and small screw terminals for input and output, you just snip both wires to the motor and attach them in parallel with it. Tweak any internal speed adjustment to the fastest speed the recorder can do, for maximum range from a bit speeded up down to massively slow