X,
Exactly, perfectly balanced H2/H3 to my ears is pretty hideous!This is the salient point in audio for most people, whether they realize it or not.
As usual, thank you for all of your hard work!
Cheers,
Greg
Hi X,
Yes, please include the option of remote mounting with using the vertical mount Molex Minifit’s. Probably include a set of the P-mos/N-mos mini mounting pcb’s with onboard snubber also.
Thanks
Some predictions of the harmonic distortion profile in LTSpice at various power levels.
I have added an RFI filter to the input and this dropped the gain a bit to 27.0dB. I am using models for the KSA992, and also replaced Q4 with a KSA1381 (or TTA004) to provide room for a heatsink in case it gets too hot.
The FFT for 8Vpp into 8ohms looks like this:
And at 27.2Vpp into 8ohms (12W), the FFT looks like this:
I think Hugh may be making some last minute tweaks to the circuit, so I won't post any updated schematics until then.
Code:
Here is 8Vpp or 1W into 8ohms:
Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 4.001e+00 1.000e+00 -0.87° 0.00°
2 2.000e+03 1.848e-04 4.619e-05 -117.68° -116.81°
3 3.000e+03 1.053e-05 2.631e-06 58.71° 59.58°
4 4.000e+03 2.313e-07 5.781e-08 104.21° 105.08°
5 5.000e+03 7.156e-07 1.789e-07 -175.07° -174.20°
6 6.000e+03 5.836e-07 1.459e-07 178.69° 179.56°
7 7.000e+03 4.936e-07 1.234e-07 178.79° 179.66°
8 8.000e+03 4.319e-07 1.079e-07 179.01° 179.88°
9 9.000e+03 3.839e-07 9.596e-08 179.12° 179.99°
10 1.000e+04 3.455e-07 8.636e-08 179.21° 180.08°
11 1.100e+04 3.141e-07 7.850e-08 179.28° 180.15°
12 1.200e+04 2.879e-07 7.196e-08 179.34° 180.21°
13 1.300e+04 2.658e-07 6.642e-08 179.39° 180.26°
14 1.400e+04 2.468e-07 6.167e-08 179.43° 180.30°
15 1.500e+04 2.303e-07 5.756e-08 179.47° 180.34°
Total Harmonic Distortion: 0.004626%(0.004808%)
Here is 27.2Vpp or 12W into 8ohms:
Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 1.387e+01 1.000e+00 -0.87° 0.00°
2 2.000e+03 2.483e-03 1.791e-04 -121.70° -120.83°
3 3.000e+03 6.206e-04 4.475e-05 59.08° 59.96°
4 4.000e+03 1.880e-04 1.356e-05 9.49° 10.36°
5 5.000e+03 7.426e-05 5.355e-06 -104.64° -103.77°
6 6.000e+03 2.763e-05 1.992e-06 177.05° 177.92°
7 7.000e+03 9.412e-06 6.786e-07 89.53° 90.40°
8 8.000e+03 1.830e-06 1.319e-07 -14.32° -13.45°
9 9.000e+03 1.956e-06 1.411e-07 -144.36° -143.49°
10 1.000e+04 1.602e-06 1.155e-07 176.37° 177.25°
11 1.100e+04 1.070e-06 7.715e-08 172.05° 172.93°
12 1.200e+04 9.599e-07 6.922e-08 -179.95° -179.08°
13 1.300e+04 9.312e-07 6.714e-08 -179.74° -178.86°
14 1.400e+04 8.648e-07 6.236e-08 179.34° 180.22°
15 1.500e+04 8.025e-07 5.786e-08 179.38° 180.25°
Total Harmonic Distortion: 0.018517%(0.018564%)
Here is 50Vpp (just before clipping) or 39W into 8ohms:
Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.496e+01 1.000e+00 -0.89° 0.00°
2 2.000e+03 1.405e-02 5.630e-04 -158.12° -157.23°
3 3.000e+03 1.391e-02 5.574e-04 56.44° 57.33°
4 4.000e+03 8.589e-03 3.441e-04 -21.73° -20.84°
5 5.000e+03 6.813e-03 2.729e-04 -135.45° -134.56°
6 6.000e+03 3.939e-03 1.578e-04 118.95° 119.84°
7 7.000e+03 3.691e-03 1.479e-04 3.52° 4.41°
8 8.000e+03 3.049e-03 1.222e-04 -101.34° -100.46°
9 9.000e+03 3.149e-03 1.261e-04 169.39° 170.28°
10 1.000e+04 2.769e-03 1.109e-04 84.89° 85.78°
11 1.100e+04 2.897e-03 1.161e-04 5.17° 6.06°
12 1.200e+04 2.717e-03 1.088e-04 -77.65° -76.76°
13 1.300e+04 2.811e-03 1.126e-04 -163.48° -162.59°
14 1.400e+04 2.513e-03 1.007e-04 107.42° 108.31°
15 1.500e+04 2.402e-03 9.623e-05 16.13° 17.02°
Total Harmonic Distortion: 0.098380%(0.099638%)I have added an RFI filter to the input and this dropped the gain a bit to 27.0dB. I am using models for the KSA992, and also replaced Q4 with a KSA1381 (or TTA004) to provide room for a heatsink in case it gets too hot.
The FFT for 8Vpp into 8ohms looks like this:
And at 27.2Vpp into 8ohms (12W), the FFT looks like this:
I think Hugh may be making some last minute tweaks to the circuit, so I won't post any updated schematics until then.
Attachments
With Tina , it is possible to start the distortion measurement after an adjusted delay because the beginning of the burst there is the transient function . To know the measurement is the steady state distortion the phase shifts should be 180° for the pair harmonics and on phase for odd ones . Your measurements are wrong , at 13Vp or 10W , Tina after 10ms delay measures 0.012% lower than yours , look at post 16.
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R7 plays important roll in trade off ,speed vs distortion . I adjust it for optimum speed to get 0.0055% Dtot. There is still margin in NFB as the sensitivity is high, but I will leave it to the spec of the designer. Tina doesn't have the bc327/40 model , with, it will still be better.
Attachments
To my knowledge, Hugh has used "Nirvana" to identify upgrade kits for his commercial products since the original AKSA 55. This is nothing new in the commercial AKSA scheme of naming things, at least.
The "Audio Nirvana" company just seem to market their own tube amps and a class D amp, their own speaker drivers, box plans and a powered subwoofer box, direct from St Louis. I wouldn't expect to see much confusion arising on this forum, at least.
This is 4 ohms version . It has 0.0047% at 10w and 0.1% at 39w . The MOSFETs dissipate each 43.9w.
:
Attachments
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I'm no expert, but my guess is that with global negative feedback the output is 'voltage output push pull' - if you want reactive inductor or current source behaviour you need to remove the global negative feedback. This amp uses a CCS yes, in a SRPP type of topology (it's been used before as an alternative to the Aleph current source) but the speaker will 'see' an amplifier with low output impedance dominated by the behaviour of the feedback loop.
All correct, Bigun........
One thing; the active CCS is concertina, the voltage across the two sources resistors will remain constant at 0.65V, but the two resistors will pass conjugate currents which will always sum to 3.4A. The two resistors are identical so that the see-saw action is completely symmetrical.
HD
One thing; the active CCS is concertina, the voltage across the two sources resistors will remain constant at 0.65V, but the two resistors will pass conjugate currents which will always sum to 3.4A. The two resistors are identical so that the see-saw action is completely symmetrical.
HD
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I thot about that, and it is the Nirvana part that bugs me, The speaker company ruined the use of the name Nirvana — so far i have heard no ANs that weren’t bad except one, and it was too pricey, so so far i have mixed views on them.
dave