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I am not really sure what prompted me to replace the old TDA1514 based power amp. Maybe I was just curious to see what was now out there. I'd sort of heard that Class D was the current platform and after scouting around a bit settled on a ESP design. It soon became apparent that sourceing the components (not supplied) was going to be an issue so the boards are still languishing in a drawer somewhere.

Hypex Electronics had some interesting kits but they came pre-built which took the ...

tda1514.jpgDoes anyone recognize this? Nope, I thought not. This is how power amps were built before the internet and order-by-computer kits.

I lived and worked in the UK for a couple of years around 1990 just when the electronic DIY scene was getting going. At university in South Africa my best mate came from a family of electronic engineers so I'd got some exposure there and found it fun though I didn't pretend to understand too much of the theory.

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Here is my 3-way boombox built using an AMP11-LV.

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You can find the full story at http://keremdiypatrick.blogspot.com/

As an example of this procedure, these measurements and calculations were performed for two different speakers. Both are four inch speakers. The first, is a Projects Unlimited AS10004PS-WR-R that features a rubber surround. The other, a CUI INC GF1004H with a cloth surround. From here onward, the speakers will be referred to by their surround type. In addition to the above measurements, driver impedance measurements were taken over the full audible frequency range.

Results
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If this relationship holds, the Q values can then be calculated.
Mechancial Quality Factor:



Electrical Quality Factor:
[IMG]Electrical Quality Factor:[/IMG]


Total Quality Factor:



To find the volume of air that will give the same acoustic compliance as the driver, ...