BC 441/461 transistors

[quote author="q2audio"]In order to show my lack of total understanding, it would appear that the devices used for current boosting are not terribly critical to the "sound" of the circuit they are being used in? I'm referring to their use in the output of DOA's etc.[/quote]

Better a lack of total understanding than a total lack of understanding.

I'm sure there are some who will hear fine distinctions between any device used anywhere, but particularly if the ones under discussion are enclosed within a global feedback loop and don't have other problems (too slow, too fast, not able to handle the power) most would say they are not critical to the "sound".

[quote author="bcarso"]
I'm sure there are some who will hear fine distinctions between any device used anywhere, but particularly if the ones under discussion are enclosed within a global feedback loop and don't have other problems (too slow, too fast, not able to handle the power) most would say they are not critical to the "sound".[/quote]

That is what I pretty much assumed. I have seen enough devices go obsolete and get replaced by something else and the sound just doesn't seem to change much if at all. A lot of this whole "sound" thing amounts to splitting audible hairs.

In the case of BC461, they have low Hfe and high drive capability. In my experience, OEMs tend to use such parts for low gain / unity applications, to give low output impedance and plenty of oomph. I've swapped 461s around with other more modern transistors that have lower Cob, and I couldn't hear or measure a massive difference. I suspected that the modern parts had a sliightly more crisp HF, but that could be precognitive bias from me because I know they have lower Cob, or it could also be due to the lower Cob accentuating very slight ringing in the transformer they were driving.


Justin