Speaking of eBay

[William Donzelli]

> One, carbon composition vs. film resistors. It's not
> unreasonable, it turns out, to be able to hear the difference
> between them (in early stages). Voltage rating. Carbon Comps
> (CC) handle HV (600 VDC) well, films not so well. Likely near
> max V all sorts of microvolt-level wierdness begins in the
> film jobs, plus micro-arc-overs, leakage paths, etc.

Seem to me that these are just crummy, underrated film types.

> CC's are
> noisy, and noise injection is complex, but may have dynamic
> characteristics that are simply not spec'd.

Composition resistors also are not stable. They drift over time. 

William Donzelli
aw288 at osfn.org