On Mon, Aug 8, 2011 at 8:00 PM, V G wrote: > Hi all, > > I bought a cheap guitar-computer interface off of dealextreme: > > http://www.dealextreme.com/p/guitar-to-usb-interface-link-cable-for-pc-ma= c-recording-130cm-32874 > > It works very well and GarageBand/Guitar Rig totally rock. Latency is > minimal as well. I don't think I can notice it with the proper > settings. > > Anyway, there seems to be a very high frequency hiss sound on certain > amp models/configurations on both GarageBand and Guitar Rig (have yet > to try logic studio) which makes me question whether or not the guitar > interface is at fault. I want to do a spectrum analysis on the output > of the thing and see what's going on. Does anyone here know of any > good (free if possible) real time spectrum analyzer software for > Windows? I want to be able to view what audio is coming out of this > guitar interface. > Thank you everyone for the software suggestions. I analyzed the output of m= y guitar interface and this is what I got: Nothing plugged into the input: http://solarwind.byethost7.com/noinput.png Guitar 1/4" analog cable plugged into the input: http://solarwind.byethost7.com/input.png Input or not, there seems to be some significant high frequency noise (not the obvious 60Hz) that doesn't seem to be coming from the guitar. My regula= r amp is completely noise free (as far as I can hear at the volumes I use, an= d I can hear very well). It's not a deal breaker, but it's still there and it's annoying to use on some amp models/pedals/effects that tend to boost those frequencies. I think I have two options now: either buy a better quality guitar interface, or make my own. I think I have the ability to make my own since it's just pretty much: opamp, etc -> ADC -> microcontroller -> USB client chip -> computer The USB drivers also seem to be standard and ASIO4all is a very good driver= .. The question is, do you guys think this would be hard? Waste of time? What are your opinions on this? The advantage of making one myself is that I could add as my inputs/outputs as I want and build in a mixer, etc. I could also use high quality and low noise components and build in hardware filters for annoying frequencies (50/60Hz). --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .