HIGH QUALITY TPU DVD Video Released from Jack Durban

[Mannix]

Actually I did go over all this with Steven and he was just fine after the smoke cleared! There's nothing left to want. For myself and many others there is closure on a handful of long outstanding issues. For those who wished Steven harm they were denied his phone number and email address. I only want peace and happiness for him and his family.

I should conclude this as some will see this as soap operatic.

My question was

Do you still see Steven as "Cashier level" tech ability?

Lindsay

[aleks]

A microphone like any other mechanical structure will have a natural resonant frequency.

It's going to be very high if you consider e.g. a 5mm diaphragm (or alike structural size for piezo mic). If speed of sound in the structure is e.g. 2000m/s then the "uncontrollable" resonant frequency will be around 400kHz, that's pretty much above the projected excitation frequency (which is around 5kHz).

For the sake of experimentation I would suggest using pro audio grade condenser mics that have no self-oscillation in at least 20-20kHz range, and stand SPLs at least 140 dB: they are usually priced at $200 and above, and require phantom power - the ones I'm referring to usually come as 3/4" barrels about 5" long. The external enclosure may be removed and its going to be a very compact device. You may also get a cheap mixing board for its phantom-powered pre-amps (usually 2 XLR inputs).

What I personally like in acoustic resonance (if it is how TPU works) is that you can create a truly de-coupled control/collector, without risks of run-away like in the case of induction windings. Control is decoupled because no changing electrical potential on the collector will affect mic in any way: there will be only minor mechanical feedback and only if the windings are poorly wound (insulated windings will probably give no mechanical feedback at all). The main resonance mic should catch is from the overall structure, or from its largest and heaviest elements (e.g. solid toroid or a pack of iron wire).

To further minimize current-induced run-aways piezo mics should not be used as they will react on external electric field.

[aleks]

@watssup
i found this on the net its a simple circuit to build a inverter for blacklight lamps you could use your coils in the circuit and it should oscillate by itself, without a microphone. consider the lamp as the load.

I think it's a wrong deal. What the purpose of random self-oscillation? Self-oscillation should be structural and that means that mechanical coupling to external toroid is required. Your scheme does not show means to do it: induction feedback does not necessarily mean it will lock to the required structural resonance. Mic can be attached anywhere on the toroid to catch the required resonance.

[wattsup]

@JD

One question about SM so we can be clear. Do you know if it was actually SM that was in communication with Mannix. I think if anything, that one point should be made clear enough or expanded upon, if possible.

I realize if the feedback is too strong, it could destroy the microphone. Hmmmmmmm. So if I am too close to the true resonant frequency, and if the amplitude is strong enough it could destroy the microphone. Analogies anyone.

@all

Can't wait to get back home tonight and start doing some testing.

Now I was thinking about speakers and microphones. I know this is all pretty rudimentary compared to all the more sophisticated designs and orientations taken here but I am trying to stick with what physically fits inside an FTPU, no more, no less. This will hopefully help others advance in other ways. That's what we do here.

Well, we know a speaker coil needs current to produce a sound and a microphone needs sound to produce a current, but does the microphone also need a small seed current to make its coil/diaphragm like float inside its magnet so it can then respond to sound vibrations more easily. What I mean is when you plug a microphone into an amplifier input, is there any current on that input to start with or is it really a dead input.

[aleks]

and if the amplitude is strong enough it could destroy the microphone. Analogies anyone.

Nope, it won't destroy microphone in almost any case: it may only saturate it, but to break it you have to put much more acoustic vibratory energy than your ears may even bear.

Usually only condenser mics need phantom power. Dynamic mics do not need one - they provide enough power for noiseless pre-amplification. For very precise experimenting you will probably need a condenser mic due to its superior dynamic and frequency response. After that you may switch to ultra-cheap dynamic heads with a noisy and choppy response.

As I've replied earlier, such acoustic stimulation is as safe as it can be: acoustics can't do much physical harm. As long as your "magoid"'s amplifier is safe and correctly designed you do not have to worry even about pricy mics and pre-amps. The only question remains is whether such resonant acoustic stimulation will deliver surplus energy on collector windings or not.