Excessive capacitance doesn't come up often with regular magnetic coil loudspeakers, but electrostatic panels have quite a bit of it. And in the case of the amp / loudspeaker set I'm hoping to build here, It can be quite a problem. So the question I'm asking is, how do you tell how much capacitance an amplifier design can drive, without building it and going the 'lets try and see' approach?
The amp design I'm looking at is basically a scaled-up version of Kevin Gilmore's ES headphone amplifier design at Headwise . The panels are going to be full-range and LARGE; as large as i can make them. It's direct-drive, so there's no transformer in there to load; it's (almost) the same as wiring a capacitor across the output of an amp and letting it rip. Of course, the panels' capacitance is defined by its area and stator spacing, so in order to get as large a panel as possible, I need to know how to determine an amp's maximum capacitance tolerance.
So how do you calculate the limit capacitance? What mechanism is at work here that eventually drive the amp to explode? As I understand it, it deals with driving an amp into UHF oscillation. Any experience of pointers on this topic would be great, and of course criticism and commentary are welcome. Thanks.
- Jonathan
The amp design I'm looking at is basically a scaled-up version of Kevin Gilmore's ES headphone amplifier design at Headwise . The panels are going to be full-range and LARGE; as large as i can make them. It's direct-drive, so there's no transformer in there to load; it's (almost) the same as wiring a capacitor across the output of an amp and letting it rip. Of course, the panels' capacitance is defined by its area and stator spacing, so in order to get as large a panel as possible, I need to know how to determine an amp's maximum capacitance tolerance.
So how do you calculate the limit capacitance? What mechanism is at work here that eventually drive the amp to explode? As I understand it, it deals with driving an amp into UHF oscillation. Any experience of pointers on this topic would be great, and of course criticism and commentary are welcome. Thanks.
- Jonathan