[R-390] OT: Transistor Amplifier Question

[Barry]

I apologize for asking an OT question but I'm not an EE and I don't find an answer to this with Google.

I'm refurbishing my Marantz 1060 stereo amplifier (bought it new in the mid-1970s).  On the preamp boards, some of the the transistors (BJTs) have a small value ceramic cap (50pF or less) connected directly between base and emitter.  Can someone tell me the purpose of these caps?  I'd presumed they might have been put there for spurious oscillation issues but I'm thinking that may not be the case.

>From what I've read, a BJT has "natural" capacitance between the junctions so most schematics I see don't seem to need any additional capacitance.

Is it possible that those addressed some problems with the older BJTs and newer ones might not need that?

Thanks for any comments and, again, apologies for the OT post.

Thanks,
Barry - N4BUQ