![]() ![]() ![]() Lowering the capacitance is exactly what needs to be done as it raises the resonant frequency of the cartridge. Too high and it also scoops out the midrange to an extent. So the thing to remember about loading and capacitance is that capacitance determines the frequency of the resonance (inversely, lowering one means raising the other), loading dampens the resonant peak but rolls off frequencies above. It gives a resonant frequency of 16.6kHz but with optimal loading at 47kHz, which dampens the resonant peak and rolls off above 17-18k, but as any cutting engineer will tell you, they roll of highs above 14-15kHz anyway to avoid overheating the cutting heads. If one gets the total capacitance to about 204pF, this is the optimum value for an AT150MLX. However, since the optimal load with that comes out to about 61kohms, I was underloading, which rolls off not only the highs above the resonant frequency, but also tends to cause a dip in the midrange. When I removed the capacitors, it moved the calculated resonant frequency up to 21.7kHz. ![]() With a 220pF pre-amp+120 wiring gives a resonant frequency at 11.3kHz, which is exactly where mine was peaking when I played white noise from a test record and observed a spectral view. Ther AT150MLx has an inductance of 450mH (according to AT). The only way I got the brightness tamed was to reduce the capacitance by removing the input capacitors from my 640P, thereby relying only on the capacitance of my interconnects and internal turntable wiring (typical total is about 120-150pF. I know it well as I used to own an AT150MLX and run it through a 640P. Click to expand.Lowering the capacitance is exactly what needs to be done as it raises the resonant frequency of the cartridge. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |