Some thoughts on how the TPU might work.

[z_p_e]

@all or @z_p_e

On the large TPU he has two yellow caps that remind me of crossover capacitors for audio. From your experience on the size of those caps, are they generally used for low frequency woofer, midrange or for a high frequency tweeter?

Those caps aren't likely any larger than 10uF or 22uF max. They could also be much lower in value but with a higher voltage rating, however, I would assume that as SM has dabbled in loudspeaker/cross-over design, they are probably between 1uF and 22 uF.

The two larger electrolytics we see near the ring perimeter are likely for output filtering, and the components across them bleed-off or equalizing resistors.

[otto]

Hello all,

@BEP

just look at the 3stack.jpg and look very carefully!!! What do you see??

Dont say you see only 3 collectors with controls!! Take your time and look!!! Think about that the TPU is 44mm high, or for our US friends 1 3/4".

I must say that I builded my 3stack TPU and it works fine but I made a mistake and have to do it again.

Otto

[Gustav22]

...
just look at the 3stack.jpg and look very carefully!!! What do you see??

Hi Otto,
I see this:

About the collector:
It is three separate coils of multi strand copper wire laid one on
top of the other, not interleaved.
Three is important.
You can do many things with three coils.
You can run them in parallel, you can run two in series and one in
parallel, or etc.
You can run a separate frequency into each coil for better control
on large power units if need be.
The control wiring is vertically wound in several segments around
each of the horizontal collector coils.
Other control wires are wound around all of the horizontal
collector coils together.

But please tell us what exactly YOU see. Please, no guessing games.
Bitte Otto, keine ratespiele, wenn's nicht unbedingt sein muss.

Viel erfolg, und mach hinne ... 

[otto]

Hello all,

@Gustav22

maybe this time I can post??

Look at the distances between the collectors and at the distances between each collector and control coil.

Otto

[Grumpy]

If you look...