Raising amplifier supply voltage from 12 to 16V

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I see people doing this all the time to gain power with unregulated class d amps but what are the actual downfalls? I understand if you use the same amount of resistance with the 16V that you do at 12V you gain power (theoretically) but also increases heat output and loss of efficiency. Now with this said is it possible to run at 16V but raise the resistance value from say 1.5 ohms to 3 ohms to reduce power output and reduce the load on the amp thus increasing overall efficiency? The benefits of running on a 16V is to decrease current draw and supply a safety cushion from undervoltage situation. ANy input would be appreciated... :)
 
thats what competitors usually do when increasing voltage...raise the load to a higher ohm when raising the voltage, to avoid drawing to much current and blowing the amp...

but this is also dependent on the intended use, if its for daily driving a higher ohm would be safer, but for a 10 second burp it may be safe at the lower load, but you have to take impedence rise of the box into consideration at the frequency played.
 
Ya, makes sense. Is it the amplifier load that determines the rail voltages? Is there anything out there I can read that would give me better insight on how amplifier components opperate and interact together? I have the amp repair tutorial but it really doesn't explain how everything works. Thanks...Polo.:)
 
The rail voltage of an amplifier can be either regulated or unregulated. In the case of a regulated supply, the maximum voltage is set and will not increase above that point no matter the B+ voltage. In an unreglated amp, the voltage is determined by the B+ input voltage and the transformer ratio.

For stiffly regulated supplies, the rail voltage will generally remain the same for a relatively wide range of B+ input voltage with the lowest rated speaker load.

For moderately regulated supplies, the rail voltage will likely sag when driving the lowest rated load. This is not necessarily a bad thing. As with any supply, there are pros and cons.

For amps being run for competition, they often use ohm loads lower than the lowest rated for the amp. Under these conditions, even a stiffly regulated supply will sag. Using 16v allows the amp to maintain the target rail voltage even driving extremely low ohm loads. This often leads to amplifier failure but for competition, it's not really a concern.


If you have my tutorial, the information is included. Most of this is also included on the 'regulated vs unregulated' page (p. 101) of my site. Even the basic amp repair page (p20) of the site has links to the various pages that tie all of this together.
 
I have your CD, great material but it doesn't inlcude the basics of class D's and showing what each component does and why. I want to know what happens to the input power at each stage and how it is all converted and controlled. It isn't all that difficult especially with schematics and an O-scope to repair an amp, but being able to look at each component and learn what it does is another thing. Is there any material out there that can explain this to me, even in basic form it would be usefull. Polo..
 
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