Topic: Playback speed on digital recording

[blindcan]

I'm just testing out my setup (AKG 390>UA-5>H-120, total n00b), and i got a total weird result. recording optical out from the UA-5 to the H-120 optical in, the recording plays back really fast, like the chipmunks. i have the sampling rate on 44.1 because i don't really know about the other settings. is this a sampling rate problem?

[Nick Graham]

It sounds like the UA5 is putting out a 48k signal while the iRiver is recording it at 44.1

[Fatah Ruark (aka MIKE B)]

Little FYI

On the UA5, it will send out the signal from how the unit was set when you TURN IT ON!. So if you have it on and set to output a 48k signal, and you switch it to 44.1, you need to turn the unit off, then back on (if you want to record 44.1).

I've done that before. 

[blindcan]

i didn't actually touch the sampling rate knob. it has been on 44.1 all along. the iRiver is supposed to record at the rate that the UA-5 is putting out. mind you, the speed difference is not just a little off. it is WAY fast. like a tape on Play/FF.

[Brian Skalinder]

This is a fairly common problem with many ADCs and recorders:  the ADC outputs one sample rate while the recorder "sees" another sample rate;  i.e. while the data itself is recorded at the proper sample rate from the ADC, the recorder writes the wrong sample rate to the WAV header resulting in the file playing back at the wrong sample rate (speed).  Simple solution:  do -not- resample;  simply re-write the WAV header.  Most commonly used audio editors will perform this function (WaveLab, Samplitude, Audacity, Audition, etc.).  Note that it's not always clear from the software's feature selections whether one is re-writing the header or resampling.  Easy way to tell:  re-writing the WAV header is an instantaneous process, while resampling typically takes time.  (Audacity may be an exception to this note - if you're using Audacity, check the Audacity Workflow thread).

[blindcan]

thanks, Brian. So do you think if i reset the sample rate on the UA-5 to 48, i might get it to match what the H-120 is reading? i also read that it is sometimes necessary to get the signal going through the cable before plugging into the H-120. i am going to test that theory today. any thoughts?

[blindcan]

figured it out, thanks to help here and on the Team iRiver board. it's not so much that you need a signal before plugging into the iRiver, but that you need to plug in BEFORE TURNING ON the iRiver. that way, the iRiver can figure out the sampling rate. it is also correct that if you want to change the sample rate, you have to turn the UA5 off, select the sample rate, then turn it back on. you would also need to shut down the iRiver and wait to turn it back on til you have a signal coming from the pre-amp.

Alright! Looks like i am all set to go. i'll let y'all know how it comes out. Thanks!