High pitched noise on USB mic recordings

[Capricorn12]

I did suspect that the 5v supply was the culprit so used my oscilloscope on the 5v input to the mic and also after the filter in the mic and there was no real interference more than a few millivolts in there. There were two decoupling capacitors that normally I would have replaced if I had the tackle to do it but the mic is now back at Editors Keys for a free estimate of cost to repair it.

[kozikowski]

Do write back if/when the problem is resolved.
Koz

[Capricorn12]

Just an update in my Editors Keys SL 600 mic problem with the high pitched data noise on it. I have got the mic working with just the 5volts from the USB port and not the data connected as I blew the codec IC. Have ordered a new IC and will fit it soon but Editors Keys contacted me and said they have a fully working Mk 2 SL600 mic that I can have for free as they can't sell it. Mine is a Mk 1 version so the Mk 2 should be brilliant I am gobsmacked at this and look forward to playing with a working mic. Cheers malc

[Capricorn12]

Will post again if I cure the Mk 1 mic I have and also report on the Mk 2 model when I get it. Malc

[Trebor]

Hi Again this is a short recording of silence for few seconds to show the whistle.
Attachments Whistle.wav Whistle demo (742.09 KiB)

If you can't prevent this whistle it can be notched-out using Steve's Code below in Nyquist Prompt.

Whistle, before-after Steve's de-whine code.flac

(1007.41 KiB) Downloaded 84 times

Code: Select all

    (setq mysound s)
    (setq q 10)         ; set the base Q for the filter
    (setq iter 15)     ; set the number of iterations
    (setq freq 1000)  ; set base frequency

    ; start the DO loop
    (dotimes (i iter mysound)   
    (setf mysound (notch2 mysound (* freq (1+ i)) (* q (1+ i))))
    )                     ;end of loop

[Capricorn12]

Well after a lot of faffing about I finally have a solution. The Mk 2 SL 600 that Editors Keys gave me was very low output so they gave me an SL 150 that is fine. The old Mk 1 SL600 does not work on USB any more but has been kept as it does have the same capacitor diaphram as the SL150 so may come in handy for spares or I may modify it to a basic non USB mic. So far the only problems I am encountering are cutting the noise from the fan on the PC that is being picked up by the mic, but this is being discussed on another thread on here and is close to a solution.