I need some way of monitoring the battery voltage level (do I? – I think I should) so they can be charged when too low.
I will not do this automatically as that would mean creating another circuit board to measure the voltage and then switching to charge mode when dropped to a low enough level. But also to switch out the output as the power is switched over to stop any loud pops. More cost and more space to take up so I don’t like that idea. Besides, I would rather have that control myself so it doesn’t all happen right in the middle of a track.
My intention is to put a meter on the front panel which is fed from one channel’s battery pack and when the level is too low, the user will see that and switch the outputs off and then switch to ‘charge’ mode.
Once the battery levels drop enough the volume will decrease (maybe quite fast) and distortion will creep in. That will be heard but I feel I should have something a little more accurate and less ‘right at the last moment’.
Do I use an analogue meter (moving iron / moving coil) – Expensive. Possibly introducing Radio Frequency Interference. Quite deep so would make the box, which is large enough already, be even larger.
Do I use digital (LCD or LED) – Inexpensive. Accurate. Possibly generating RFI. Nice and small.
And the above doesn’t factor in the look of the device.
For me the obvious answer is to use an analogue device as I fear the digital types would introduce some small amount of RFI. But maybe digital would not affect sound quality in any perceivable way and analogue would increase the overall depth of the amp cabinet by about 5cm which seems a lot considering that increase is for the meter only.
I have been trying to decide what to do for a long time now, but decision crunch time is rapidly approaching.
If anyone has any input or idea please do feel free to pass it on to me – that’s assuming anyone reads these ramblings!