I don't think there is a need to match Menahem, just use them as is :-)

According to the circuit, this is a place I'd definitely like to match, for stablest motor operation, at the lowest heat radiated.

Whenever I see what I like to call the NPN and PNP "holding hands" and looking in a mirror, similar to the output transistors in an amplifier, so I invest a little extra effort in matching.

On this PCB, it's already a known problematic and stressed area of the circuit, with the PCB's turning dark brown under the heat-discolored metal can transistors, and I think the goal should be to do whatever's necessary to eliminate that unnecessary wear and tear, as much as is practicable.

hFe matching is a fairly painless and effective way of doing this.

Just my 0.02 !

A  lowly speaker cross

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Ricardo wrote:

A  lowly speaker cross

Hang on, you weren't Ricardo??? What the heck have I missed while I been gone :-p

Video I promised - I turned the video upside down so the meter was right way up, in case anyone was wondering!

My next two projects 😁

Wish I had more time, this B&O certainly keeps me busy...

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I got these units form a good friend of mine so probably will get three units in full working condition again!

Same thing with the 2500 Cubes.

Leslie wrote:

I got these units form a good friend of mine so probably will get three units in full working condition again!

Same thing with the 2500 Cubes.

Help out those of us who are historically challenged! What are those? I know what the cubes are but the other has me stumped.

Those are boxes from the tube radios, but which ones?

Menahem Yachad wrote:

Those are boxes from the tube radios, but which ones?

If I am not wrong, those cases are from BEO610 (TR26). So no tube radio but very early transistor radio by B&O (maybe even the first one)...