I took some time today for trying out the PT-03 Theremin. It is an unofficial clone of the Paja Theremax and not longer sold. It comes in a small carrying case. Pictures and a brief description can be found here (http://www.myspace.com/portabletheremin). Since the circuits seem mostly identical, some of my observations may also be valid for the Theremax itself.
The instrument was left temporarily to me by a TW member because he was not at all satisfied with it. So the first thing I did was checking and correcting the tuning in order to start with "normal" parameters. After this procedure I found a more stable audio output and much less ghost tones when varying the volume.
I should mention, even if I (as a classical player) find them useless, that there are the same pitch cv, volume cv and gate outputs as on the Theremax, including the corresponding adjustment potentiometers.
It is a "classical" heterodyning theremin without a linearizing coil. A 5pF capacitor in series with the pitch rod seems to "limit" the over-proportional capacitance growth when playing very high tones. So I felt the expected behavior, decreasing space between higher tones. But this variation is consistent and smooth, so I think I could easily adapt to that in a about 5 octave range. I tried to play "Waldesruhe" op.68 no. 5 from A. Dvorak and found it not too bad, out of some "oooops" where I went too far when doing jumps into the higher register (a tribute to the non-linearity...).
The sound is more mellow than on the EW Standard, especially in the lower register, which can be pleasing but also sound uninteresting. But that depends on individual preferences. Some mods have been published on the www which allow to increase coupling between the oscillators in order to get a sharper, more string like sound. I wouldn't do this, since I prefer a mellow bass register on a theremin.
In the next days I will try to "linearize" it by adding a coil. Since mathematics are helpful but do not always allow to take all parameters into account, there will be some trial and error.
So I'll perhaps post an update when I'll have been successful.
The instrument was left temporarily to me by a TW member because he was not at all satisfied with it. So the first thing I did was checking and correcting the tuning in order to start with "normal" parameters. After this procedure I found a more stable audio output and much less ghost tones when varying the volume.
I should mention, even if I (as a classical player) find them useless, that there are the same pitch cv, volume cv and gate outputs as on the Theremax, including the corresponding adjustment potentiometers.
It is a "classical" heterodyning theremin without a linearizing coil. A 5pF capacitor in series with the pitch rod seems to "limit" the over-proportional capacitance growth when playing very high tones. So I felt the expected behavior, decreasing space between higher tones. But this variation is consistent and smooth, so I think I could easily adapt to that in a about 5 octave range. I tried to play "Waldesruhe" op.68 no. 5 from A. Dvorak and found it not too bad, out of some "oooops" where I went too far when doing jumps into the higher register (a tribute to the non-linearity...).
The sound is more mellow than on the EW Standard, especially in the lower register, which can be pleasing but also sound uninteresting. But that depends on individual preferences. Some mods have been published on the www which allow to increase coupling between the oscillators in order to get a sharper, more string like sound. I wouldn't do this, since I prefer a mellow bass register on a theremin.
In the next days I will try to "linearize" it by adding a coil. Since mathematics are helpful but do not always allow to take all parameters into account, there will be some trial and error.
So I'll perhaps post an update when I'll have been successful.
