In the winter of 2008 I bought a Pocket POD to do some headphone practice with my guitar. However after testing my new purchase for about 5min I was really disappointed by its performance, since my device featured an all time present amount of noise. I have made a recording of the behavior with my PC, and although I did not have access to a high quality recording equipment and merely used the internal sound card, it was sufficient to capture the symptoms.
I then wrote an email to Line6 support, but (as expected) until today did not receive an answer. Well what should they answer, other to admit that they just rushed out a badly designed device. I have seen complaints and questions about this on the Line6 forums from many people and nobody got any real solution, so I decided to publish my tests one and a half year after writing my email to Line6.
Below is the email I sent to Line6 support, only edited to reflect the current location of the images and sound files and some minor spelling mistakes. As of July 2009 I'm still waiting for an answer.
Hello all together, I have long used an original POD XT for live play, recording and practicing with head phones. Nothing to complain about on that device. Now after I have moved to a different country and left all my equipment at home I bought a Spider III Amp last autumn and can not complain about its performance either. I also use it a lot to practice with headphones. Now last Saturday I decided to give the Pocket POD a try, since it seemed like a good alternative for headphone practice with the benefit of better mobility than carrying around my amp... But right after unpacking the POD and turning it on I noticed, that my device is suffering from a badly designed output stage, since it has two things to complain about. 1) The device once it has booted its firmware and is working has a far higher noise level than comparable effect gear. I ran the POD from (new) batteries, so a humming power source is no cause. 2) When operating the device emits a fairly high tone, not loud but clearly audible with headphones. Now first I checked for a bad cable and tried all guitar cables of all length I have. Then I investigated if this may be a defect of the line/headphone output, but when I connected the pod to my amp via the amp guitar input the same noise and tone could be heard through the amp. I then tested turning on the pod by connecting the computer via USB and not inserting anything into its guitar input and I had the same results, both on guitar and line output on the pod. So my conclusion is, that the output (amplifier) circuit in the pod is one the one hand not designed for the usual line6 quality low noise and that some part of it is emitting this high tone on top of it. To let you better understand my observations I have made a recording of the mentioned POD behavior. Since I recently moved I unfortunately have only access to my office PCs crappy onboard recording facility, but it sufficed for some low-tech analysis. I have uploaded the sample file to my web page: http://cubic.org/~doj/PocketPOD/pocket-pod-noise-level.wav The first 5 seconds show the pod powered off, so we see the noise level of the onboard sound card. Then I power on the POD by inserting a cable into the guitar in. At about 11 seconds the POD has booted and is ready for operation. Then the high tone appears and a slightly raised noise level. If you listen carefully you notice an increase in the upper frequency noise. I have also made two spectrum analysis of the relevant parts. You can access them at: http://cubic.org/~doj/PocketPOD/pocket-pod-before-poweron.png http://cubic.org/~doj/PocketPOD/pocket-pod-during-power.png Although the db axis is slightly different in the two screen shots you can see an overall increase in the mid-frequency noise level. And I have indicated with arrows the spectral frequencies of the additional tone. Apart from those two annoyances the POD operated without problems. As I don't have access to another Pocket POD for a comparison I can not conclude if I have a device with a defect in the audio part, or if the described behavior is present in all current Pocket PODs. I have returned my POD to the dealer today, since it is of no use for me with this behavior, but I'd like to know if I might have had a defective unit.
As described in the email above here are the two spectrum analysis pictures I have made with Audacity. The first picture shows any noise present within my recording setup, as it was made with the PocketPOD connected but not powered on.
And this picture shows a running PocketPOD. You can clearly see a general higher noise present and the arrows show the fundamentals of the high frequency tone always present.
And finally you can download the PocketPOD recording in WAVE format from which the analysis above was created.
For updates, answers, questions and suggestion please contact Dirk Jagdmann <doj@cubic.org>.
Last update 2009-07-09