[linux-audio-user] Unwanted "tremolo" on mic-in with SB Audigy

[scott thomason]

Greetings. I recently purchased a SoundBlaster Audigy, thinking 
it would be a good input device for use with my guitar (having 
had problems with on-board C-Media and my former Diamond 
MX-400). I am running it under alsa-0.9.0-rc6, with linux kernel 
2.4.21-pre5 vanilla.

While using various synth tools like ams or galan (and with the 
mic-in channel muted so I only hear the synth effect), I noted 
that I wasn't receiving any input at all from the audio input 
source. Upon further investigation, I noted that it was 
necessary for me to use KDE's mixer to bump up the "IGain" to a 
non-zero setting. Unfortunately, while this causes audio input 
to occur, it has an unwanted tremolo-like effect.

Strangely, when I'm not using a synth tool and I'm just playing 
my guitar normally (with the mic-in unmuted and the IGain off), 
it sounds great. The card can accept input just fine. What's the 
deal with the IGain setting, and how can I set things up 
properly to avoid the "tremolo overload"?
---scott