I’m looking for some beta testers for a small piece of hardware as described below.
The device I’m testing is a very simple way of reducing the THD from a low cost audio generator, such as a XR2206 based one, down to the level of a good lab audio generator. Also, this device may be used to further reduce the THD of a lab quality generator to a level of below 0.0090%.
Testers must have access to a bench power supply capable of 12VDC to 18VDC and a AC voltmeter that can read accurately up to 30kcs or so. Also, testers will need a means of measuring audio THD, either with a hardware spec-A, a software based spec-A (such as ARTA) or a THD meter. In addition, a low quality audio generator (such as the type you may find on eBay) will be needed for a signal source. A good lab quality function generator will also be helpful to see if the device can further reduce THD from, say 0.07% to 0.0090% or lower.
The device is simply a tune-able audio bandpass filter with a Q high enough to reduce harmonics while at the same time being easy to tune. What I have so far is a prototype that seems to work very well on the bench and also looks good using simulation software.
What I would like to get from the testers is the following:
1. Do you think the product is useful
2. Is it too difficult or time-consuming to set-up and use
3. In what price range would something like this sell for
4. Suggestions for improvements
Of course, there is no charge for this and the filter is yours to keep.
At present, testers must be in the USA only; I hope to change this as things move on.
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