Eroica HX / LX - Q. In comparison to Eroica LX: Do you raise the voltage by using a stronger magnet or by more windings on the coils?
Answer
We use extra coil windings. The reason for this is that in order to work into a high-impedance MM input the output impedance of the Eroica HX needs to be raised accordingly and this can most easily be achieved by increasing the number of windings. Of course, at the same time more windings give us more output as you have correctly observed. We have to be careful though, as too many windings will increase the moving mass too much, which will negate some of the advantages of the cross-armature. Because the core is made of pure “Swedish” iron, the output of the coils is further enhanced, as the core provides a low reluctance path for the magnetic flux to properly interact with the windings meaning we can use fewer windings and get lower distortion than if we used an inferior material. In order to fit all the windings onto the reduced area of the cross-shaped armature core we needed to work with our magnetic wire suppliers to find a grade of wire which was thin enough and yet strong enough to provided the correct number of turns per channel. The original reason for using the square shaped armature was that it was large enough to accommodate the extra turns of standard MC wire required so, moving to a smaller armature using the same number of turns presented us with quite a challenge – however, after many trials we have found the magic combination!