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The Sunshine
By Holger Kraft
09 Aug 1997
A few words about parts quality
I used Solen Fastcaps in the whole crossover except for the 82 uF cap in the impedance linearizing circuit of the tweeter. I used them, because I like their sound. For further improvement I added a 0,1 uF Sn foil cap (IT) in parallel to the 8,2 uF filter cap in the high pass and a 0,2 uF Sn foil cap in parallel to the 60 uF (made of four 15 uF caps in parallel) phase shifter caps. After all I did not want to destroy the abilities of the Esotar tweeter. For all inductors I chose a rather large diameter, because I think in connection with a 8 W amplifier you should not waste a little bit of power in the crossover. The second reason is, that in my opinion inductors with a small diameter and big resistance do not their best to enhance the dynamic abilities of a speaker system. The third reason is that I did not want to lose a little bit of the very small damping factor of my poor SE amp. Lets say I want to make life easy for it, because one design goal was to make the speaker suitable for all 'poor' amps (SE tube, SE solid state, class a solid state, ...). OK, I need some attenuation for the tweeter and that also 'wastes' power, but.... For all the resistors I used ten 0,5W metal film resistors in parallel, like mentioned on the crossover schematic.
After all I did not design a impedance linearizing circuit for the whole speaker system. There are different reasons for it:
- I recommend bi-wiring. I have always problems to decide where the circuit should be placed. Maybe directly at the amplifier or at the entry of the low pass?
- Like I said above, I did not want to waste power and damping factor. Using an impedance linearizing circuit means, that you bleed power on a resistor in a certain frequency range.
- Impedance only rises to, lets say, 20 to 25 Ohms and the crossover is a phase corrected 6 dB/6 dB design and does not behave in a very nasty way.
Last thing to mention here would be, that I prefer, like many other popular developers here on the Internet (Dick Olsher, Lynn Olson, ...), an extra housing of the crossover because of the same reasons like the other guys mentioned before: Less vibrations on the crossover parts, better possibility for tweaking around and so on.
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