1kW MOSFET amplifier

[haldor]

HI Kilowatt,

Letting this cool off for a while is a good idea even if you have the resources now. It is human nature to try and build the most impressive thing possible for your first project, but the truth is you are much better off starting small and learning the ropes before jumping into anything too ambitions.

I'm glad to see you are taking that route. Can't wait to here that monster when you get it done though.

Phil

[Tony]

would like to find out if kilowatt finished this project or any updates, please....

[djss]

Originally posted by joan2
would like to find out if kilowatt finished this project or any updates, please....

I'm not the guy you're asking about...but I will say the boards are made for my 4++ kW amp are made (as of 1/04) and I have most of the parts. School+work means I have absolutely no time to work on the project until May, so it's on complete hold until the summer.

[av_affected]

A curious thread indeed... quite entertaining.

Here's a thought for Kilowatt:

Instead of building such a beast (although I realize that's the fun of it), you could look into used electrodynamic shaker amplifiers. These systems are used for vibration testing everything from consumer products to military/space hardware to cars and airplanes. They're essentially a huge, powerful speaker driven by a monstrous amplifier --but instead of a cone, there is a platform onto which the test product is mounted. We have several at the company I work for with 50KW water-cooled amplifiers. I know their bandwidth is at least into the 3KHz range with farily low distortion. We have played music with them on occasion for demonstrations.

You can buy the amplifiers new of course, but they will be expensive. Here's a 125,000 watt model.

...just a thought.

[djss]

I'm pretty sure those aren't built with high-fidelity in mind, but I can vouch for them being fun to use in a test facility. I interned at a place that used one regularly for something like 300 G's of vibration testing. They had 6 of those things you posted a pic of.

[Eva]

I've been following the thread and would like to expose my thoughts

If you want to produce some SPL across the entire audio band outdoors and at some distance, then the first step is to forgot direct radiation, HI-FI drivers and car-audio drivers. These drivers have null efficiency outside a car or a room as direct radiators, and high excursion units have null power handling when horn-loaded due to small cone displacement and no voice coil refrigeration]. You should start experimenting with horns, build prototypes and learn about them.


Forgot also about amplifiers, an amplifier has negligible complexity compared to a single horn loaded driver system [or even more complex : a cluster of horn loaded drivers and its directivity and mutual load issues] [or even more complex : matching the phase responses of horn tweeters and horn midranges in the crossoverr region so they sum up properly in the horizontal axis and cancel off axis]

You should get measurement software, a professional measurement mic and build some preamplifier to provide phantom power and connect the amplified output of the mic to the line in of the sound card [Behringer ECM8000 is a cheap option]

You should also get some horn simulation software, the first choice as a starting point would be 'HORNRESP' since it's free

You should get a couple of 8" or 10" PA midrange drivers suitable for horn loading [EV has great models with high BL, low moving mass and very low Le, all desirable for horn loading]. Get also four 15" or 18" drivers suitable for horn loading [Eminence has cheap good drivers] and a couple of HF compression drivers and suitable horns [preferably ready to cross over down to 1,5Khz and without marked peaks or dips in the frequency response]

For amplification really anything would do. For each HF driver just 50-100W is more than you would usually need. For midrange 300W would be enough and for LF think about 600W for each driver

Anyway, when building horn prototypes you usually build only one unit and test it before building more units, so you don't ever need 4 LF drivers to start experimenting, I started some years ago with just a 15" Hi-Fi driver, a 10" Eminence Delta 10 midrange and a MHD-152 cheap but good sounding [with some EQ] Monacor horn tweeter. I hadn't enough money for anything else

Anyway, I think the hardest part of all is crossover fine tuning to get decent sum across crossover regions.

About amplification, I actually use 80W chip amps [TDA7294 with +-40V regulated supply] for home testing of horn prototypes before trying them outdoors. You don't need 600W to know if a horn performs well or not. Just 80W at 105-108dB/W is enough to produce insane HF and midrange SPL at 3m distance in a closed room [horn radiation tends to attenuate less with distance than direct radiation and is less prone to room acoustics interaction due to directivity]

[Jesús Puerto]

Hi eva,
If you have any problems with the speakes please contact with my
friend Mairicio.
He have a lot experience with the transductors.

WWW.audioexcel.com

Anyway, when building horn prototypes you usually build only one unit and test it before building more units, so you don't ever need 4 LF drivers to start experimenting, I started some years ago with just a 15" Hi-Fi driver, a 10" Eminence Delta 10 midrange and a MHD-152 cheap but good sounding [with some EQ] Monacor horn tweeter. I hadn't enough money for anything else.

En castelleno eres muy buena en electronica, ayer tuve audicones
durante 5 horas con diiferentes cables de modulacion a razon 600€
y mas con marcas afamadas made USA and CEE y gano uno echo en Gerona.

Saludos.
Jesus

[Jesús Puerto]

Hi eva,
Excusme the web is .
www.audioxcel.com
Jesus.