Basic question, but I need to know before I proceed:
Avoid burning out speaker:
-Stay within speaker rating for amp
-Avoid clipping - listen for clipping or run output through Audacity and detect clipping
Avoid burning out chip amp:
-Check for voltage under protection on chip
-Avoid using speakers of lower impedance than recommended
-Avoid using speakers of hight impedance.
Please help, you know how DIY audio people hate to have to keep buying speakers and chips ever so often 🙂
Avoid burning out speaker:
-Stay within speaker rating for amp
-Avoid clipping - listen for clipping or run output through Audacity and detect clipping
Avoid burning out chip amp:
-Check for voltage under protection on chip
-Avoid using speakers of lower impedance than recommended
-Avoid using speakers of hight impedance.
Please help, you know how DIY audio people hate to have to keep buying speakers and chips ever so often 🙂
To avoid damage to speakers is to simply not exceed their power rating or excursion limits (limits of cone movement).
Occasional light clipping is not an issue and often not even audible. However, if the music is turned up so much that it sounds distorted, then turn it down to avoid potential damage if the amp is powerful enough.
Most chip amps have built in protective circuits that are effective, however you can still damage them by:
Exceeding the supply voltage rating. Or connecting it wrong.
Using too small of heat sink and chip runs too hot. Even though many ICs have thermal protection, it is mainly for fault protection. Running a part hot will lead to early failure after a while.
Running the IC with lower than recommended load impedance.
Just to add:
Good circuit layout means good sound. So many beginners have given up because the amp they made distorts or oscillates which wrecks the sound.
Occasional light clipping is not an issue and often not even audible. However, if the music is turned up so much that it sounds distorted, then turn it down to avoid potential damage if the amp is powerful enough.
Most chip amps have built in protective circuits that are effective, however you can still damage them by:
Exceeding the supply voltage rating. Or connecting it wrong.
Using too small of heat sink and chip runs too hot. Even though many ICs have thermal protection, it is mainly for fault protection. Running a part hot will lead to early failure after a while.
Running the IC with lower than recommended load impedance.
Just to add:
Good circuit layout means good sound. So many beginners have given up because the amp they made distorts or oscillates which wrecks the sound.
i sortha built quite a few amps for people who needed thm to be fool proof to some degree.
now here is the ugly part..
the gain is known, and the maximum input signal allso -at least in the cases i had to deal with- so a simple L-pad on the input made sure there is a hard limit on maximum output.
given speakers have a given powerhandling, a nother ugly methood was.. resistors in series with the output to make sure even at full blast no damage is done to the speakers.
and a nice big cap in series too, to avoid any chanses of dc going into the speakers.
ugly as hell.
but works well.
supposedly on the input side of the amplifier it may be posible with some zeener diode magick to really make sure input level stays within reasonable range. never done it, but it ain't impossible.
all of these methoods hurt the sound, but there is no free lunch.
surely even directly shorted terminals did not bother these amplifiers, as the series resitor was big enough to protect the chip, ad was hih enough in power rating to survive all the amp was capable.
means i had past 4 ohms right in series with the speakers.
does wreck havoc with the quality but hey. at least it keeps on working you know.
now here is the ugly part..
the gain is known, and the maximum input signal allso -at least in the cases i had to deal with- so a simple L-pad on the input made sure there is a hard limit on maximum output.
given speakers have a given powerhandling, a nother ugly methood was.. resistors in series with the output to make sure even at full blast no damage is done to the speakers.
and a nice big cap in series too, to avoid any chanses of dc going into the speakers.
ugly as hell.
but works well.
supposedly on the input side of the amplifier it may be posible with some zeener diode magick to really make sure input level stays within reasonable range. never done it, but it ain't impossible.
all of these methoods hurt the sound, but there is no free lunch.
surely even directly shorted terminals did not bother these amplifiers, as the series resitor was big enough to protect the chip, ad was hih enough in power rating to survive all the amp was capable.
means i had past 4 ohms right in series with the speakers.
does wreck havoc with the quality but hey. at least it keeps on working you know.
Thanks and a few more questions
Thanks John, I really appreciate all the advice given so far. I just got one speaker burned out - maybe it was old - but really ruined my plans. It was a cheap one, but finding a matching replacement is not easy.
The heat sink on my little PC speaker amplifier is loose and is stuck on with a clip and some greasy stuff in between. Should I re-glue and what should I use? Picture in this thread:
http://www.diyaudio.com/forums/multi-way/288970-matching-speaker-drivers-2.html#post4663727
Here with the heatsink:
http://www.diyaudio.com/forums/chip-amps/283845-pc-speaker-electronics-amplifier-conversion.html
I did build a chip amp circuit in 1995 which has an awful buzzing hum I still can hear it now, and that put me off amplifiers from 1995 to 2015 - 20 years! So I guess you are right. The internet was just starting though, for us anyway.
Thanks John, I really appreciate all the advice given so far. I just got one speaker burned out - maybe it was old - but really ruined my plans. It was a cheap one, but finding a matching replacement is not easy.
The heat sink on my little PC speaker amplifier is loose and is stuck on with a clip and some greasy stuff in between. Should I re-glue and what should I use? Picture in this thread:
http://www.diyaudio.com/forums/multi-way/288970-matching-speaker-drivers-2.html#post4663727
Here with the heatsink:
http://www.diyaudio.com/forums/chip-amps/283845-pc-speaker-electronics-amplifier-conversion.html
I did build a chip amp circuit in 1995 which has an awful buzzing hum I still can hear it now, and that put me off amplifiers from 1995 to 2015 - 20 years! So I guess you are right. The internet was just starting though, for us anyway.
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