500watt amp

[noobman92]

hey guys
first of all, i am not sure if this post regarding a subwoofer amp should be here or in any other thread, so mods, please do the needful.

now, somebody donated a speaker to me coz they werent using it anyways (its in its chassis or body, i'd say its a subwoofer with a tweeter on top).The problem is, i dont know whats its impedance and its wattage (i opened it up, no specs were specified). but then, the donator and me tried connecting it to his audio system (Sony 5900watts something), and this donated subwoofer just did not give in even at the max volume.no distortion, nothing, just bass and the song. does this say anything about the woofer? also this sony audio system claiming that 5900watts, is it that my woofer is more than 5900watts? ok if i cant measure the wattage., i still want to build an amplifier for it. atlease 500 watts, and i want to use it as a 2.1 speaker system (i have small speakers else then the subwoofer)....the question is, does anybody have a simple diy schematic for a 500w amp?i googled, but wasnt very successful. i found 300watts diy at, 300/500W Subwoofer Power Amplifier
should i try my hand at this??? or give me some 500w schematic please guys
also, i am a total noob at subwoofers and their amps!! have built Cmoys and Headbangers and transmitters, am ready to play with high voltages so i guess it might come out good....Thanks guys

[keyboard123]

Thats 5900 watts PMPO , right ? which rounds of to 50 watts RMS.

[noobman92]

thanks for the info keyboard123, but what about the amp suggestion?

[abraxalito]

500W and simple don't really go together in chip amp territory. Simple ends around 50W. 500W chip amp is certainly possible but definitely not recommended for a noob - to do it without it self-destructing you'd need an oscilloscope and a fair bit of knowledge about how to do good layout. To do real justice to a 500W amp, a subwoofer driver would need to be 15inch and 4inch voicecoil methinks. That's assuming its not a Sunfire special

[noobman92]

hey abraxalito, what about the amp in the link i provided? worth it????
also, how do i effectively (or approximately) measure the impedance and wattage of my speaker?
and is the oscilloscope and everything needed for the linked project too?

[keyboard123]

In that link you mention: did you read the warnings. Granted you've taken a few 230vac jolts in the past.
It will cost you a small fortune building the amp and speakers to match. But it will have enough power to blow the roof off and eardrums too.
I'm not discouraging you , but as Abraxalito mentions its certainly not a project for a noob.
Also will you be able to source genuine obsolete power transistors?
Try the chip amps and build your experience on them . i would suggest.
With a multimeter in Ohms range , disconnect the speaker terminals,separate the tweeter and measure across them , it is approximate, but close. let me guess its a 8 ohm spkr. you don't mention dia. but if its a subwoofer then it could be in the 100-150 watt range.

[abraxalito]

Originally Posted by noobman92

hey abraxalito, what about the amp in the link i provided? worth it????

Yeah, Rod Elliot is one of the more experienced guys putting designs out, and it looks good to me. But its certainly not a chip amp and not for an amp noob by any means. I'd say you'd better have a scope to debug it - not least for checking output transistor parasitic oscillation which might destroy them.

also, how do i effectively (or approximately) measure the impedance and wattage of my speaker?

The impedance you can quickly check with a DMM. This won't actually check the impedance, it will check the DCR (resistance). You'll need to do this in a quiet, low vibration environment though because the voice coil acts as a microphone. As for the wattage, can't be measured in a simple way, you'd need to check the manufacturer's spec.

and is the oscilloscope and everything needed for the linked project too?

As someone who's designed an amp of a similar wattage, I'd say a scope is essential with paralleled output stages of any description, discrete or chip amp. So definitely a resounding yes.

[pacificblue]

Originally Posted by noobman92

this sony audio system claiming that 5900watts

The 5900 is certainly not the output power in Watts but simply part of the model name.

Originally Posted by noobman92

should i try my hand at this??? or give me some 500w schematic please guys

Do you want to build that to save money? Are you aware that you can easily buy a commercial PA amp of that power class cheaper than you can build one?

Originally Posted by noobman92

am ready to play with high voltages so i guess it might come out good

PLAY with high voltages?