At your risk.
If any of the two 9V batteries is discharged the preamplifier goes into motorboating oscillation.
Possible cause the increased internal resistance (ie output impedance) of the battery creates voltage drop at the first stage from the current drain of the other stages. this is equivalent to an input signal or really positive feedback signal. If series resistors and then capacitors to ground for each stage were used this could solve or reduce the effect but it is decided not to use any of them.
The battery or batteries should be replaced anyway and this is a sure sign to do so.
As a remix of Such a Shame - Talk Talk was being reproduced suddenly the beat was modulated in amplitude by this very low frequency. It was thought as a production effect and may be used as such. A very interesting stereo tremolo effect. The subsonic frequency may damage equipment or ears so please keep the volume down. If the volume is already up before the batteries are exhausted it can be dangerous.
No comments:
Post a Comment