2b青年爱发烧

find the solution, just input V(out+,out-) will be OK. Fourier components of V(out+,out-) DC component:-6.40787e-008 Harmonic Frequency Fourier Normalized Phase Normalized Number [Hz] Component Component [degree] Phase [deg] 1 1.000e+03 1.441e+02 1.000e+00 -0.93° 0.00° 2 2.000e+03 5.728e-08 3.976e-10 -3.00° -2.06° 3 3.000e+03 1.966e-04 1.365e-06 -22.41° -21.48° 4 4.000e+03 1.111e-07 7.712e-10 -0.34° 0.60° 5 5.000e+03 2.646e-06 1.837e-08 -164.58° -163.65° 6 6.000e+03 1.705e-07 1.183e-09 2.85° 3.79° 7 7.000e+03 2.017e-07 1.400e-09 20.00° 20.93° 8 8.000e+03 2.243e-07 1.557e-09 1.29° 2.22° 9 9.000e+03 1.429e-06 9.920e-09 163.50° 164.43° Total Harmonic Distortion: 0.000136% the THD is fairly good

Since the KGSSHV Carbon is famous as a reference of electrostatic amp, I think it would be better to do some spice simulations to check the baseline of its circuit. Many components were not found in LTSPICE so I used similar ones instead. It works except the quiescent current at the output stage is large. (Anyone could please tell me what it is ?) Now I meet a problem, that is, how to use the fourier transfer directive (.four) on the voltage between two output ? I tried many way but all failed: Fourier components of V(out+) DC component:-3.16154 Harmonic Frequency Fourier Normalized Phase Normalized Number [Hz] Component Component [degree] Phase [deg] 1 1.000e+03 9.355e+01 1.000e+00 -0.93° 0.00° 2 2.000e+03 2.356e-02 2.518e-04 -94.27° -93.34° 3 3.000e+03 2.172e-04 2.321e-06 -21.46° -20.53° 4 4.000e+03 5.108e-05 5.460e-07 128.27° 129.21° 5 5.000e+03 3.615e-06 3.864e-08 -154.01° -153.07° 6 6.000e+03 5.703e-07 6.096e-09 -51.12° -50.18° 7 7.000e+03 1.475e-07 1.577e-09 7.65° 8.58° 8 8.000e+03 1.874e-07 2.003e-09 16.11° 17.04° 9 9.000e+03 8.659e-07 9.256e-09 164.63° 165.56° Total Harmonic Distortion: 0.025185% .fourier quantity "V(v(out+)-v(out-))" not pressent in data. Thank you. Yes I can check it in the FFT draw, but still want a text report.

thanx, I'll check it out yes there are quite many fake ones, have to pick carefully.

Thanks very much for your reply~ 1) I checked out mouser and other sale sites, really there was no more high voltage P type devices, sad...but found a few 2sa1968 on taobao.com, maybe I can use them. 3) what if short the resistor? yeah...maybe it's dangerous. 5) sorry I remembered it wrong, is it better with a follower?

planning to build an electrostataic amp for my SRM L700. I have built several amps for my Moving coil earphones (HD650, K601, K702...), but never built an electrostataic one, I read some topics about it, also some diagrams of amps , there are still some questions need your help. 1. Never saw the full differential structure (for example, opa1632, lme49724) used in the electrostataic amp, why? 2. The electrostataic earspeakers have much larger impedance than moving coil ones, the only capacitive impedance is isolated by the output resistor (usually 5.1k), so...the electrostataic amp works like without loads? 3. Why the output resistor is usually 5.1k ? 4. The bias terminal also has a resistor, maybe it will affect the sounds ? 5. Is the emitter follower necessary ? I noticed that the stax lower price amps (323, 353x) possess an emitter follower, it was said that "has enabled wide-range reproduction resulting in both the extended dynamic range at high frequency and the improved tone quality"....but the higher price products (717, 727, and other tube amps) DO NOT use emitter follower, so... I'm puzzled. Temporarily above, many thanks~~~

I think it's hard to obtain good performance because usually the CFA needs a proper value of feedback resistor, but the resistance in electrostatic amps is too large.