BD249C in pairs, Musical Fidelity Elektra E1

[cpunotfound_66]

Hi, just bought the amp in object second hand.
So far, I was unable to find the schematic on Internet.
Yesterday I opened it, to clean and look at the circuit.

The power transistors are two pairs of BD249C, not BD249/BD250.

It is correct? Possible?
Does anyone have an example of a similar configuration?

Thanks in advance
Giuseppe
Italy

 

[Mooly]

Does it work ?

If it does then its correct and the amplifier uses a 'Quasi Complementary' type output stage which was very common and popular some years ago.

 

[cpunotfound_66]

Yes, it works.
...and much better than I was expectig, as the reviews I found, from this particular model, range from fair to under-average.
So, thanks, now I know the right topology to study

 

[JensenHealey]

Musical Fidelity do not make it easy to find circuit diagrams.

 

[Kay Pirinha]

The BD249C is/was a better variant of the BD249, as it's U_{CEO max.} is 100 Vdc (vs. the BD249's mere 40 V).
Best regards!

 

[john_ellis]

Seems to be obsolete but equivalent to the TIP35C which isn't (last time I looked).

 

[Mooly]

I think we were after either the correct circuit or examples of Quasi stages rather than looking for replacements.

This is a typical Quasi stage with two NPN power transistors as the final output.

 

[john_ellis]

Yes, I nearly added the words "just in case you needed to replace them".

 

[cpunotfound_66]

Yes, thanks. I'm waiting for a friend to return me my ESR-tester, as I plan to begin evaluating capacitors health status.