"Revolvr" wrote, inter alia,
in rec.audio.tubesYICgb.52990$vj2.19457@fed1read06:

: I have also looked at a couple of PC based software scopes that work with
: the soundcard inputs and outputs. A couple that look promising are
: AudioTester at
:
: http://www.audiotester.de/
:
: And TrueRTA at
:
: http://www.trueaudio.com/rta_abt1.htm

You might also like to look at http://www.dazyweblabs.com/
I've downloaded all these, but haven't actually tried them yet.
Sure are "purty" looking interfaces though,
and the site seems tube-friendly, too ...
[My 0.02c ... maybe others have tried their suite out?]
RdM
(back, after isp difficulties and changeovers ... ;=})