Anyone want some paid work designing an amplifier?

You're looking at class D then. I'm not far from Leeds, but I think

Paul Burke

Don't forget the Karaoke input -- if a 100W / channel jukebox is a crime against humanity, what is 100W / channel Karaoke?

Take care with your terminology. Here's an amplifier that's described as "compact" -- is this what you meant?

Yep, but I'd play this only on high efficiency speakers with at least

"Watt inflation". Look at the teensy tiny little craptacular PC-clone amplified speakers that claim to be capable of 35 Watts when they sound tinny at their best sounding power level (which is realistically 0.1W).

Tim.

Geez, I get room-filling sound at less than that.

But then, these are vintage 12" woofers, too. ;-)

Tim

Hello Tim,

Yesterday I had the "pleasure" to listen to some kind of digital media player booster with speakers. It was the worst and most distorted sound I heard in decades yet the thing cost almost $200. A bullhorn was top notch HiFi gear compared to that junk.

I can certainly do this. Pro/commercial audio is my speciality. It won't be cheap though if that's what you were hoping !

Where exactly are you btw?

Graham

The email address in my headers works - feel free to contact me

Just so I understand, when you say 4 channel, do you really mean 4 inputs and 4 outputs or do you mean 2 input channels with two sets of speakers on each channel?

Most of the PCs I find have just two audio outputs. I guess higher end sound cards will have 4 channel output. Is that what you expect this unit to connect to?

I would be interested in discussing this design. You can contact me at rick dot collins dot "the current year" at arius dot com. I can't seem to do enough to prevent spam!

media

sound

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Would that be a SONY system with the "unique" SONY brand class D amplifiers?

I recently listened to such a system and my conclusion was that they should have bitten the bullet and just paid the licences on the IPR and made a decent product instead of the D-I-Y (in the very worst sense) product they ended up with.

Here is a bit more of the spec:

100 watts per channel, this is just a max value 50-70 watts rms or even less would be ok as long as quality and volume did not suffer.

Must be small and really compact, size is an issue if we want to miniturize our jukeboxes

must have tone controls

remote wired volume control

input source from pc sound card line out

mic input (pre-amped onboard)

auxillary input for background music systems (line level input)

jukebox audio to imediately cut out auxillary audio

auxillaty audio to fade back in gradually after jukebox audio track ends

echo facility for microphone

microphone must have two operating modes:

mode 1 anouncment mode (music volume automatically reduced to allow audible mic)

mode 2 karaoke mode (music volume levels maintained)

To clarify the 2 or four channels, a single stereo input is needed to the amp from the sound card. The amp should have to stereo channel so that four seperate mono channels can be controlled independently. This give the system the ability to control four seperate sound areas.

Steve

Just a couple things. Of course it depends on your application.

Automatic volume control is needed or perhaps ideal, if the source material is not level matched.

Mono music really sucks. Big gripe with me listening to bar music. Its cost more to run stereo, but then you have stereo.

Most bar speakers really suck, especially generic MTX (here in the US) boxes improperly designed and placed for the application.

greg

Hello Frithiof Andreas,

I don't remember, could have been. I just decided that grandpa's old tube radio is a better performer. Even on the AM band :-)

Every time I listened to someone's iPod or MP3 gear I was not enthused. The sound just wasn't like that from even my car stereo. Oh well, I can live with MP3, wav, or whatever.

In message , dated Fri, 8 Sep

It would rather compromise the karaoke ballad singers. Everything at the same volume.

... for the guy standing at the right spot, yes. For everyone else, not much.

People think audio is easy, and loudspeakers are easiest of all. None of it is true. I have a demo, using the same small drive unit in different boxes. it goes from tinny and strangled to 'Gosh, is that a 12 inch unit?' Oh, the boxes are made from corrugated cardboard (I can't remember the US English word). Of course, inch-thick high-density board, lead-lined and smoked over baobab wood shavings would sound better, but not as much improvement as getting the box size and shape right does.