diff --git a/man/alsa_in.0 b/man/alsa_in.0
index 8841b1d..096c860 100644
--- a/man/alsa_in.0
+++ b/man/alsa_in.0
@@ -28,6 +28,18 @@ Set Client Name.
 .br
 Use this Soundcard.
 .TP
+\fB\-v\fR  
+.br
+Verbose, prints out resample coefficient and other parameters useful for debugging, every 500ms.
+also reports soft xruns. 
+.TP
+\fB\-i\fR  
+.br
+Instrumentation. This logs the 4 important parameters of the samplerate control algorithm every 1ms.
+You can pipe this into a file, and plot it. Should only be necessary, if it does not work as
+expected, and we need to adjust some of the obscure parameters, to make it work. 
+Find me on irc.freenode.org #jack in order to set this up correctly.
+.TP
 \fB\-c \fI channels\fR  
 .br
 Set Number of channels.
@@ -36,37 +48,35 @@ Set Number of channels.
 .br
 Set sample_rate. The program resamples as necessary.
 So you can connect a 44k1 jackd to a soundcard only supporting
-48k.
+48k. (default is jack sample_rate)
 .TP
-\fB\-m \fI max_diff\fR  
-.br
-The value when a soft xrun occurs. Basically the window, in which
-the dma pointer may jitter. If you see "delay=" in the output of alsa_out
-this is too small.
+\fB\-p \fI period_size\fR  
 .br
-Make sure target_delay is bigger than this.
+Set the period size. It is not related to the jackd period_size.
+Sometimes it affects the quality of the delay measurements.
+Setting this lower than the jackd period_size will only work, if you
+use a higher number of periods. 
 .TP
-\fB\-t \fI target_delay\fR  
+\fB\-n \fI num_period\fR  
 .br
-The delay alsa_io should try to approach. Tune this to get lower latency.
-Must be bigger than max_diff for alsa_out, and should be bigger than max_diff+jackd_period
-for alsa_in. 
+Set number of periods. See note for period_size.
 .TP
-\fB\-f \fI catch_factor\fR  
+\fB\-m \fI max_diff\fR  
 .br
-This value sets how fast the samplerate will change.
-default is 1000. Try 10000 when you have good relation between
-your clocksources. This will make resampling inaudible for example.
+The value when a soft xrun occurs. Basically the window, in which
+the dma pointer may jitter. I dont think its necessary to play with this anymore. 
 .TP
-\fB\-p \fI period_size\fR  
+\fB\-t \fI target_delay\fR  
 .br
-Set the period size. It is not related to the jackd period_size.
-Sometimes it affects the quality of the delay measurements.
-Thats why its configurable.
+The delay alsa_io should try to approach. Same as for max_diff. It will be setup based on -p and -n
+which is generally sufficient.
 .TP
-\fB\-n \fI num_period\fR  
+\fB\-C \fI P Control Clamp\fR  
 .br
-Set number of periods. See note for period_size.
+If you have a PCI card, then the default value (15) of this parameter is too high for -p64 -n2... Setting it to 5 should fix that.
+Be aware that setting this parameter too low, lets the hf noise on the delay measurement come through onto the resamplerate, so this
+might degrade the quality of the output. (but its a threshold value, and it has been chosen, to mask the noise of a USB card,
+which has an amplitude which is 50 times higher than that of a PCI card, so 5 wont loose you any quality on a PCI card)
 
 .SH AUTHOR
 Torben Hohn