PA Chime Generator: Difference between revisions
Matt Parnell (talk | contribs) No edit summary |
Matt Parnell (talk | contribs) No edit summary |
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* In April, a BT8040N was extracted from an eBay-purchased InterM PA-1000BR amplifier. While functional - the sound wasn't <i>quite right</i> (more on this below). | * In April, a BT8040N was extracted from an eBay-purchased InterM PA-1000BR amplifier. While functional - the sound wasn't <i>quite right</i> (more on this below). | ||
* A Texas Instruments C2000 evaluation board was selected as the "brains" per familiarity in the designer's day job. Over the course of months, code was written to control the chime, microphone mute, button LED and a small LCD display via button trigger. The code functionality is described in more detail in a separate section. | * A Texas Instruments C2000 evaluation board was selected as the "brains" per familiarity in the designer's day job. Over the course of months, code was written to control the chime, microphone mute, button LED and a small LCD display via button trigger. The code functionality is described in more detail in a separate section. | ||
* In August, a | * In August, a BXA4230K came onto the market via eBay, extracted from an Inkel PA-9100RC (the exact model previously owned by Fairway). This chip <i>sounds exactly right</i>. | ||
== Design == | == Design == | ||
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When and if time permits, a final schematic will be produced to show the as-built hardware in its entirety. | When and if time permits, a final schematic will be produced to show the as-built hardware in its entirety. | ||
== BT8040N versus BXA4230K == | |||
While these parts are pin-for-pin compatible, and seemingly listed as drop-in replacements, there is no doubt that the BXA4230K has a distinctly different sound than the BT8040N. The tone progression interval, pacing and decay (with external circuits) are very similar. The BX4230K, however, has lower fundamental tones, and additional harmonics and/or sustained tones. I don't have captured audio samples - but I can say that if you've heard the PA-9100RC chime, you won't be satisfied with the BT8040N. I wasn't. | |||