Jan Didden is a talented audio engineer and author with a well-stocked lab in Turnhout, Belgium. He recently gave us a tour of space and talked about his current audio design projects.
This is an excellent place to work. It is a converted army barrack so, being an old army man myself, I feel comfortable here. Above me there is the Tax department and one floor below there is a medical department. I am safe from all sides. I have two rooms, one for studying and listening and one for all the projects and equipment.
One of his current projects is an amplifier for electrostatic speakers.
An electrostatic speaker works with a very thin foil to make the air move. To get that thin foil moving you need to apply a high voltage. That is normally done with transformers that transform the low voltage audio signal from the amplifier to a higher value. But a transformer is not a linear component and can introduce all sorts of distortion to the signal. The solution is to make an amplifier that produces a high voltage output directly, but there are not many transistors capable of providing these high voltages.
He also described a project he might showcase on Kickstarter in the near future.
My other project is very interesting for people who are using computers for measurement and testing audio. They all use a sound card (internal or external) but these cards have a limitation on the input voltage. That is typically around the 1 V. The project I am working on is an ‘auto ranger.’ It automatically scales the signal to measure to the right input voltage for the sound card. I think a lot of people will like that and I hope to make this product available, perhaps by making it a Kickstarter project.
