Time delay

Oops!

Any speaker must be connected to an separate delayer ... It MUST be done electronically..

If you want a delay of a few milliseconds you could do it in analogue, but greater than that you would probably need a digital solution.

A tighter spec would be required

martin

martin griffith =D9=86=D9=88=D8=B4=D8=AA=D9=87 =D8=A7=D8=B3=D8=AA:

Hello Martin,

Thanks,

Yes That delay time is enough, Digital does not seem to be a good choice for only 7 transducers, so I prefer the analogue solution. Do you know any scheme to do the job with a constant response on all audio frequencies?

I think you are out of your depth, you should go digital, but do you need a custom solution. There are many delays on the market, but I'm out of touch, for the last year or so

The bbc did a delay line for an audio compressor in the 70's, just a millisecond or so, can't remember the device number, but it would have cost several thousand pounds in those days, and that is just for one quality channel.

You need to be specific, like, frequency reponse, distortion, delay time, noise, delay adjustment etc. Without that discussion is meaningless

martin

An All-Pass filter with a crossover frequency of Fo will have a delay of 1/Fo (IIRC), for all frequencies below Fo.

So, if you need 20KHz response, you can get 50uSec per section... only takes 20 sections to get 1mSec ;-)

...Jim Thompson

I was trying to forget all that , but EF86 or 12AT7's?

Pick your weapon

martin

Oops!

Any speaker must be connected to an separate delayer ... It MUST be done electronically..

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Do a Google search on CCD analog delay. People messed around with these in the 1970s. Might still be viable if you want analog. I have no idea what the distortion spec would be.

Tam

I haven't done anything with a tube in it since around 1960 ;-)

...Jim Thompson

Always found that the metalwork was worse than the electronics. Too much blood.

But back to the OP, he should check out the wavefront semi al3101, weird but useful, despite the visciously crap documentation and software. I would have used it if I could have figured out the delay buffer

martin

But I do still own a fairly complete set of Greenlee chassis punches ;-)

...Jim Thompson

I still own 10 fingers

martin

Me too.

Pretty hard to cut yourself on a chassis punch ;-)

...Jim Thompson

Trivial when you try to remove the punchee.

a long spring with mag tranducers at each end! :)

Clamp it in a vice and push it out from the back with a screwdriver or scratch awl. If too many are sticking in the die you should buy one of the newer "Slug buster" versions.

Naaah! There's a hole in the top piece. Clamp in a vise and knock out the "punchee" with a nail or Phillips screwdriver ;-)

...Jim Thompson

I've punched many hundreds of holes in control panels and chassis with Greenlee punches, and can't remember getting a scratch. The punched slug usually comes out very easily when you screw out the bolt and give the bolt head a sharp rap on the concrete floor.

Now, *drilling* sheet metal (especially thin cheesy aluminum or steel) can get hairy if you don't secure the metal on the drill press, don't provide a sacrificial back-up behind the part, and a large-diameter drill bit catches as it breaks through.

Best regards, Spehro Pefhany

All pass filters would be a poor choice for this project since they generate delay at the damped frequency, not delay across the audio spectrum. [You use all pass filters to equalize group delay by adding delay in specific regions.]

The choice (and a poor one) for this project would be a Bessel (Thompson) filter. However, if you need miliseconds of delay across