Para-Magnetic Current Amplifier

[Tyimo]

Hi!

Do somebody know this kind of amp???

http://www.lizardwizardaudio.com/pmctheory_en.html

I wouldlike to understand how it works

I even don't know what would be the correct place for this thread!

Tyimo

 

[Jan Dupont]

A Class D Amp working as a Current generator ??

 

[QSerraTico_Tico]

Hi!

Do somebody know this kind of amp???

http://www.lizardwizardaudio.com/pmctheory_en.html

I wouldlike to understand how it works

I even don't know what would be the correct place for this thread!

Tyimo

I don't understand a word of it! But who am I? [joke]
Either it's BS or a stroke of a genius.

 

[Tyimo]

A Class D Amp working as a Current generator ??

No. There is no active device like transistor, Fet or Tube in the amp. (as I know...)

They use an electromagnetic (iron core) coil and control the coil's fluxus with a resistor.

 

[Tyimo]

I don't understand a word of it!

Me too! And even in my own mother language....

 

[Jan Dupont]

And how would you control the flux without any active components ???

 

[jaycee]

With a flux capacitor!

1.21 Gigawatts!

 

[Steven]

Obfuscation

To me it seems just an amplifier with an output resistance of, say, 4 ohm. Of course, the frequency response will just change depending on the actual speaker impedance at a certain frequency.
This can be accomplished by inserting a 4 ohm resistor in series with the output, or by a combination of voltage and current feedback. The latter solution has lower losses (dissipation).
I admit that this simple solution does not completely explain the shown graphs (see Measures on their site). At low frequencies (from 20Hz), the output impedance differs from the impedance at 1kHz, but in strange way. With 3 ohm load the output impedance is rather low at 20Hz, while with 36 ohm load it is rather high at the same 20Hz.

Steven

 

[Tyimo]

And how would you control the flux without any active components ???

I don't know... O.K. May be there is an active component, but not in the signal pass. May be, but I heard that there isn't any....

Some little info:
http://blog.stereophile.com/hifinews2006/092406lizard/

 

[analog_sa]

I don't know... O.K. May be there is an active component, but not in the signal pass. May be, but I heard that there isn't any....

This is really great: finally a passive power amp to complement the passive pre in my green room

Of course there may also be a pair of chipamps transformer coupled to the speaker.

 

[tvi]

patent GB224...

I think this is the patent?
GB2241621

An amplifier which drives reactive loads and in particular loudspeakers in a more efficient and effectively linear manner than previous amplifiers. An amplifier which does not clip the voltage output under conditions of normal drive or over drive from the input signal. (see fig. 9).
From this amplifier an output current proportional to the input signal is produced across the load and the output voltage is seen as a result of the load's impedance and emf. This voltage being available for feedback against the incoming signal; thus scaling the output current with respect to the impedance and emf of the load. This enables linear power driving of electrically and electromechanically reactive and or linear loads. (see fig.7). An amplifier where the damping current flowing through both the devices is inversely proportional to the output current drive and that maximum damping is provided in the static position where the output impedance equals the load impedance for maximum power transfer from this position. (see fig. 8).

Also might want to check meidy Audio

Regards
James

 

[tinitus]

It says "virtual coil-amp" ... wouldnt that mean there IS no coil, but electronics that behaves like one ?

 

[dnsey]

It's clear from the blurb on the Meidy Transmagnetic Convertor that it does include a solid-state (i.e. conventional?) amp, but has a 'coil output'.
My guess is that this is some sort of transformer incorporating a feedback winding.

 

[Tyimo]

I think the Meidy is the same amp, but made by a different firma.

Some more info:

The input signal arrives to a couple resistor. Then goes once to the internal cable and to its terminating resistor and goes once to the volume level potentiometer (ALPS „Blue Velvet”) sliding contact pin. The potentiometer connected as a two pole, the other pin grounds the signal, the third pin left floating. From the internal cable teminating resistor, the signal goes to the base of a low noise bipolar transistor. The volume level potentiometer has two functions:

O.K. Now it's getting clearer. There is still active device in the signal pass.
I am afraid that the "mystic" and the "pathos" was bigger around this amp than the real technical invention. It remind me to the Pathos acoustic's famous Inpol theory..... I mean: a simple and well known technology was transcribe with heavy "new looking" technical text.

Tyimo

 

[bodri]

The Lizardwizard and Meidy has the same electric designer, but the amp is totally different.
Meidy has big and heavy coils, it warms up quickly, LW is working with the same tecnology, but there is only a small device (coil) provides the flux, small size, no heat.