Zenquito Variants - SK170 SJ74 ...drive 2SK1058

[lineup]

Experiences with using 2SK170 + 2SJ74 for Zenquito ?

How about voltage? SJ74 is max 25 Volt. SK170 = 40 Volt, alright.
For +/- 34 Volt I will need some cascoding.
With bipolar? Maybe BC550C/BC560C?

The Zenquito version I have in mind, see Schematic below.
Uses 2SK246 + 2SJ103 and I can not easily get those.
But I can find supplier in my country for SK170/SJ74.


Thanks for any useful information for the interesting Zenquito amplifier.


Muchos Regardas, Lineup

 

[jackinnj]

The forward admittance of the K170/J74 are much higher than the K246/J103 -- about 10x higher. You might want to check out the Vishay, OnSemi or Fairchild JFETs -- although their noise stats are much worse.

 

[darian]

No problem with the higher transconductance of these devices. There will just be some more gain at the first stage and so, some more open loop gain. No stability issues. Actually, there is many version of the Zenquito/Buzquito using these too.

 

[darian]

Just use cascoding like this Buzquito version...

 

[darian]

Sorry I forgot to attach the schematic...

 

[lineup]

Using the straightforward Zenquito concept
to drive a pair 2SK1058/SJ162
it is possible to make a real HiFi amplifier.

Image shows the simplified Zenquito concept.

 

[lineup]

This configuration shows very little distortion.
1 Watt 8 Ohm, THD 0.00044%

Max output at +21/-21 Volt is more than 16 Watt.

 

[MiiB]

If you add a current mirror the higher order harmonics will be even lover...

and you have a fully scalable design.. if you then split the supplies...the amp could be very good..

 

[lineup]

I will try.
What you mean split supplies?
And how should I put mirrors?

 

[WuYit]

lineup,
I would keep the common source output stage topology.

 

[MiiB]

Here a model with current mirrors and cascode...a fully scalable design. Just add output sets the needed SOA. It SIM's with rather low distortion and also a good distortion distribution..!!

But must still say that I have a little problem with the split and having complimentary parts handling the signal.

The one J-fet amplifier you previously pulled out of the hat....I fancy that...

 

[Bonsai]

This configuration shows very little distortion.
1 Watt 8 Ohm, THD 0.00044%

Max output at +21/-21 Volt is more than 16 Watt.

I really like the simplicity of this circuit Lineup! And the results look very good as well.

 

[WuYit]

MiiB,
most of the nice features of the original design are gone. The input cascode is OK, but there`s no need for another VAS.

 

[fotios]

Very nice circuit Lineup! I know that you like very much symmetrical input stages and you are right on this.
We could use the channel bridging mode to increase the output power, keeping thus the supply voltage in low level instead cascading transistors. In such a case, we need 4 channels (instead the ordinary two) for making a fully symmetrical (balanced) from input to output stereo amplifier.
Just an idea, because i have a 2 X 21V / 200VA toroid surplus which can provide an output power (according to bridge mode) of 2 X 70 Wrms / 8 Ohms.

 

[MiiB]

What do you mean.. The VAS is already there...Here I am just setting the current in The VAS by using current mirrors...this lowers the higher order harmonics...

The Cascodes are there so it can be scaled to higher voltages

 

[WuYit]

I see that, nevertheless, the cascoding transistor is a voltage amplifier. By adding another voltage amplifying stage and altering the common source stage into source follower the design is made more mediocre compared to the original Zenquito. This amp will behave very differently.

 

[lineup]

I like the MiiB 60/50 Volt variant.

The original Zenquito can be made in different flavours.
Lower voltage, higher voltage, Class AB, Class A.
See here: 2A & DIY

Personally I like amplifiers with lower power.
It is enough for most cases.

It is striking how simple amplifiers can be designed
with Lateral MOSFET, 2SK1058/2SJ162.
If I was to build a power amplifier I would go this way.

 

[WuYit]

OK, now I understand, the topology I had in mind obviously has many names, Zenotron, zenItron, Amperotron...I`m very sorry.

 

[Boscoe]

I realise this is an old thread but lineup could you do me a favour?

Could you sym this schematic for me?

An externally hosted image should be here but it was not working when we last tested it.

I'm interested if you could sym it with 50V supplies with 2 pairs of 2sk1058 and such at 1W and full power into 4 and 8ohm? If you could that would be really appreciated!

Thanks!

 

[Jay]

.step v=0.1
Fourier components of I(load)
DC component:0.00104633

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.632e-01 1.000e+00 179.96° 0.00°
2 2.000e+03 3.269e-07 1.242e-06 91.91° -88.05°
3 3.000e+03 3.966e-07 1.507e-06 -171.78° -351.74°
4 4.000e+03 2.717e-09 1.032e-08 67.16° -112.80°
5 5.000e+03 3.363e-09 1.278e-08 17.35° -162.60°
6 6.000e+03 5.825e-09 2.214e-08 27.88° -152.08°
7 7.000e+03 5.835e-09 2.217e-08 20.89° -159.07°
8 8.000e+03 6.166e-09 2.343e-08 11.85° -168.11°
9 9.000e+03 6.636e-09 2.522e-08 12.96° -166.99°
Total Harmonic Distortion: 0.000195%


.step v=0.2
Fourier components of I(load)
DC component:0.00104536

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 5.263e-01 1.000e+00 179.96° 0.00°
2 2.000e+03 1.291e-06 2.452e-06 92.15° -87.81°
3 3.000e+03 3.219e-06 6.116e-06 -171.59° -351.55°
4 4.000e+03 2.711e-08 5.150e-08 156.68° -23.28°
5 5.000e+03 2.037e-08 3.871e-08 172.50° -7.46°
6 6.000e+03 2.661e-08 5.056e-08 171.82° -8.14°
7 7.000e+03 3.157e-08 5.998e-08 164.73° -15.23°
8 8.000e+03 3.562e-08 6.767e-08 172.97° -6.98°
9 9.000e+03 4.218e-08 8.013e-08 178.62° -1.34°
Total Harmonic Distortion: 0.000659%

.step v=0.3
Fourier components of I(load)
DC component:0.00104379

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 7.895e-01 1.000e+00 179.96° 0.00°
2 2.000e+03 2.836e-06 3.592e-06 91.09° -88.87°
3 3.000e+03 1.090e-05 1.380e-05 -171.35° -351.31°
4 4.000e+03 4.381e-08 5.549e-08 117.63° -62.33°
5 5.000e+03 4.914e-08 6.224e-08 36.84° -143.11°
6 6.000e+03 1.831e-08 2.320e-08 23.51° -156.45°
7 7.000e+03 1.760e-08 2.230e-08 24.20° -155.76°
8 8.000e+03 2.185e-08 2.768e-08 35.44° -144.52°
9 9.000e+03 2.331e-08 2.953e-08 31.64° -148.32°
Total Harmonic Distortion: 0.001426%

.step v=0.4
Fourier components of I(load)
DC component:0.0010417

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 1.053e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 4.818e-06 4.577e-06 90.13° -89.82°
3 3.000e+03 2.611e-05 2.480e-05 -171.18° -351.14°
4 4.000e+03 1.591e-07 1.511e-07 130.02° -49.94°
5 5.000e+03 1.473e-07 1.399e-07 33.94° -146.02°
6 6.000e+03 1.149e-08 1.091e-08 -52.51° -232.47°
7 7.000e+03 4.603e-09 4.373e-09 -126.04° -306.00°
8 8.000e+03 4.989e-09 4.739e-09 -29.17° -209.13°
9 9.000e+03 9.521e-09 9.046e-09 -2.03° -181.98°
Total Harmonic Distortion: 0.002522%

.step v=0.5
Fourier components of I(load)
DC component:0.00103927

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 1.316e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 7.028e-06 5.342e-06 88.44° -91.52°
3 3.000e+03 5.172e-05 3.931e-05 -170.98° -350.94°
4 4.000e+03 4.977e-07 3.783e-07 132.93° -47.03°
5 5.000e+03 4.375e-07 3.325e-07 38.91° -141.05°
6 6.000e+03 3.031e-08 2.303e-08 -107.99° -287.95°
7 7.000e+03 6.282e-08 4.774e-08 -172.09° -352.05°
8 8.000e+03 6.861e-08 5.215e-08 172.31° -7.65°
9 9.000e+03 7.181e-08 5.458e-08 171.73° -8.22°
Total Harmonic Distortion: 0.003968%

.step v=0.6
Fourier components of I(load)
DC component:0.00103688

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 1.579e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 8.900e-06 5.637e-06 84.98° -94.98°
3 3.000e+03 9.113e-05 5.773e-05 -170.71° -350.67°
4 4.000e+03 1.307e-06 8.281e-07 130.24° -49.72°
5 5.000e+03 1.275e-06 8.075e-07 37.13° -142.83°
6 6.000e+03 1.333e-07 8.446e-08 -70.67° -250.62°
7 7.000e+03 1.588e-07 1.006e-07 -162.22° -342.18°
8 8.000e+03 1.223e-07 7.747e-08 169.18° -10.78°
9 9.000e+03 1.152e-07 7.296e-08 172.72° -7.24°
Total Harmonic Distortion: 0.005801%

.step v=0.7
Fourier components of I(load)
DC component:0.00103534

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 1.842e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 9.336e-06 5.069e-06 76.49° -103.47°
3 3.000e+03 1.487e-04 8.073e-05 -170.33° -350.29°
4 4.000e+03 3.309e-06 1.797e-06 127.68° -52.28°
5 5.000e+03 3.356e-06 1.822e-06 36.32° -143.64°
6 6.000e+03 5.912e-07 3.210e-07 -53.64° -233.59°
7 7.000e+03 4.368e-07 2.372e-07 -146.12° -326.08°
8 8.000e+03 2.191e-07 1.190e-07 157.43° -22.53°
9 9.000e+03 1.243e-07 6.748e-08 152.40° -27.56°
Total Harmonic Distortion: 0.008093%

.step v=0.8
Fourier components of I(load)
DC component:0.00103668

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.105e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 6.990e-06 3.321e-06 38.78° -141.18°
3 3.000e+03 2.312e-04 1.098e-04 -169.78° -349.73°
4 4.000e+03 8.575e-06 4.074e-06 125.32° -54.64°
5 5.000e+03 8.655e-06 4.112e-06 36.04° -143.92°
6 6.000e+03 2.300e-06 1.093e-06 -49.30° -229.25°
7 7.000e+03 1.532e-06 7.280e-07 -137.98° -317.94°
8 8.000e+03 7.084e-07 3.366e-07 145.38° -34.58°
9 9.000e+03 2.751e-07 1.307e-07 79.06° -100.89°
Total Harmonic Distortion: 0.011005%

.step v=0.9
Fourier components of I(load)
DC component:0.00104797

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.368e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 2.257e-05 9.531e-06 -50.50° -230.46°
3 3.000e+03 3.546e-04 1.498e-04 -168.79° -348.75°
4 4.000e+03 2.637e-05 1.114e-05 123.21° -56.74°
5 5.000e+03 2.552e-05 1.078e-05 36.06° -143.89°
6 6.000e+03 1.087e-05 4.591e-06 -48.25° -228.21°
7 7.000e+03 7.770e-06 3.282e-06 -135.02° -314.97°
8 8.000e+03 4.545e-06 1.920e-06 139.65° -40.30°
9 9.000e+03 2.978e-06 1.258e-06 53.73° -126.23°
Total Harmonic Distortion: 0.015101%

.step v=1
Fourier components of I(load)
DC component:0.00108826

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.630e+00 1.000e+00 179.96° 0.00°
2 2.000e+03 9.579e-05 3.642e-05 -66.43° -246.38°
3 3.000e+03 5.529e-04 2.102e-04 -167.28° -347.23°
4 4.000e+03 7.586e-05 2.884e-05 121.96° -58.00°
5 5.000e+03 6.698e-05 2.547e-05 35.87° -144.09°
6 6.000e+03 2.925e-05 1.112e-05 -48.71° -228.67°
7 7.000e+03 1.594e-05 6.060e-06 -135.53° -315.48°
8 8.000e+03 2.774e-06 1.055e-06 134.97° -44.98°
9 9.000e+03 3.851e-06 1.464e-06 -125.88° -305.83°
Total Harmonic Distortion: 0.021718%

.step v=1.1
Fourier components of I(load)
DC component:0.00113792

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 2.893e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 1.757e-04 6.073e-05 -68.60° -248.55°
3 3.000e+03 7.902e-04 2.732e-04 -166.62° -346.57°
4 4.000e+03 1.025e-04 3.543e-05 121.70° -58.25°
5 5.000e+03 8.378e-05 2.896e-05 34.90° -145.05°
6 6.000e+03 7.929e-06 2.741e-06 -52.96° -232.91°
7 7.000e+03 9.812e-06 3.392e-06 50.32° -129.64°
8 8.000e+03 2.673e-05 9.241e-06 -40.86° -220.82°
9 9.000e+03 2.356e-05 8.143e-06 -129.09° -309.05°
Total Harmonic Distortion: 0.028386%

.step v=1.2
Fourier components of I(load)
DC component:0.00117725

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 3.155e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 2.259e-04 7.161e-05 -68.94° -248.89°
3 3.000e+03 1.069e-03 3.387e-04 -166.42° -346.37°
4 4.000e+03 8.817e-05 2.794e-05 121.82° -58.13°
5 5.000e+03 8.957e-05 2.839e-05 33.21° -146.75°
6 6.000e+03 3.900e-05 1.236e-05 131.12° -48.83°
7 7.000e+03 3.262e-05 1.034e-05 45.23° -134.73°
8 8.000e+03 4.629e-05 1.467e-05 -44.38° -224.33°
9 9.000e+03 1.846e-05 5.850e-06 -137.16° -317.12°
Total Harmonic Distortion: 0.034916%

.step v=1.3
Fourier components of I(load)
DC component:0.00120097

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 3.418e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 2.439e-04 7.136e-05 -68.82° -248.78°
3 3.000e+03 1.385e-03 4.053e-04 -166.47° -346.42°
4 4.000e+03 5.081e-05 1.487e-05 122.92° -57.03°
5 5.000e+03 8.255e-05 2.416e-05 32.33° -147.62°
6 6.000e+03 7.768e-05 2.273e-05 128.38° -51.57°
7 7.000e+03 5.856e-05 1.714e-05 40.28° -139.68°
8 8.000e+03 3.503e-05 1.025e-05 -51.16° -231.11°
9 9.000e+03 1.340e-05 3.920e-06 -145.95° -325.91°
Total Harmonic Distortion: 0.041363%

.step v=1.4
Fourier components of I(load)
DC component:0.00121555

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 3.680e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 2.443e-04 6.640e-05 -67.80° -247.75°
3 3.000e+03 1.727e-03 4.694e-04 -166.57° -346.53°
4 4.000e+03 8.916e-06 2.423e-06 151.49° -28.46°
5 5.000e+03 5.468e-05 1.486e-05 31.99° -147.96°
6 6.000e+03 9.790e-05 2.660e-05 126.89° -53.06°
7 7.000e+03 8.530e-05 2.318e-05 39.17° -140.78°
8 8.000e+03 6.794e-06 1.846e-06 -89.03° -268.99°
9 9.000e+03 1.524e-06 4.141e-07 88.41° -91.54°
Total Harmonic Distortion: 0.047561%

.step v=1.5
Fourier components of I(load)
DC component:0.00122125

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 3.942e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 2.297e-04 5.827e-05 -65.07° -245.02°
3 3.000e+03 2.097e-03 5.320e-04 -166.64° -346.59°
4 4.000e+03 4.144e-05 1.051e-05 -69.98° -249.93°
5 5.000e+03 1.244e-05 3.157e-06 22.63° -157.32°
6 6.000e+03 1.059e-04 2.686e-05 127.98° -51.98°
7 7.000e+03 9.876e-05 2.505e-05 40.12° -139.83°
8 8.000e+03 3.135e-05 7.953e-06 142.20° -37.75°
9 9.000e+03 2.960e-05 7.508e-06 47.94° -132.01°
Total Harmonic Distortion: 0.053670%

.step v=1.6
Fourier components of I(load)
DC component:0.00121575

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 4.204e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 1.974e-04 4.696e-05 -61.05° -241.00°
3 3.000e+03 2.504e-03 5.956e-04 -166.81° -346.76°
4 4.000e+03 9.117e-05 2.169e-05 -66.64° -246.59°
5 5.000e+03 2.656e-05 6.317e-06 -143.36° -323.31°
6 6.000e+03 1.035e-04 2.462e-05 128.17° -51.78°
7 7.000e+03 9.620e-05 2.288e-05 38.78° -141.17°
8 8.000e+03 5.714e-05 1.359e-05 136.89° -43.06°
9 9.000e+03 5.570e-05 1.325e-05 48.41° -131.54°
Total Harmonic Distortion: 0.059915%

.step v=1.7
Fourier components of I(load)
DC component:0.00119304

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 4.466e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 1.484e-04 3.323e-05 -53.37° -233.32°
3 3.000e+03 2.961e-03 6.631e-04 -166.92° -346.87°
4 4.000e+03 1.404e-04 3.144e-05 -64.21° -244.16°
5 5.000e+03 6.279e-05 1.406e-05 -148.40° -328.35°
6 6.000e+03 9.878e-05 2.212e-05 125.82° -54.13°
7 7.000e+03 8.359e-05 1.872e-05 35.42° -144.53°
8 8.000e+03 7.439e-05 1.666e-05 136.61° -43.34°
9 9.000e+03 8.332e-05 1.866e-05 45.02° -134.93°
Total Harmonic Distortion: 0.066588%

.step v=1.8
Fourier components of I(load)
DC component:0.00115807

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 4.727e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 8.648e-05 1.829e-05 -26.75° -206.70°
3 3.000e+03 3.470e-03 7.341e-04 -166.95° -346.90°
4 4.000e+03 2.017e-04 4.267e-05 -64.50° -244.45°
5 5.000e+03 8.276e-05 1.751e-05 -153.71° -333.66°
6 6.000e+03 9.121e-05 1.929e-05 126.55° -53.40°
7 7.000e+03 5.598e-05 1.184e-05 27.20° -152.75°
8 8.000e+03 8.465e-05 1.791e-05 134.81° -45.14°
9 9.000e+03 9.831e-05 2.080e-05 45.95° -134.00°
Total Harmonic Distortion: 0.073668%

.step v=1.9
Fourier components of I(load)
DC component:0.00109999

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 4.989e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 9.077e-05 1.820e-05 50.81° -129.14°
3 3.000e+03 4.053e-03 8.125e-04 -166.83° -346.78°
4 4.000e+03 2.709e-04 5.431e-05 -64.64° -244.59°
5 5.000e+03 8.888e-05 1.782e-05 -164.84° -344.79°
6 6.000e+03 8.653e-05 1.735e-05 124.84° -55.11°
7 7.000e+03 2.605e-05 5.222e-06 -15.87° -195.81°
8 8.000e+03 8.799e-05 1.764e-05 133.10° -46.84°
9 9.000e+03 1.113e-04 2.231e-05 46.51° -133.44°
Total Harmonic Distortion: 0.081539%

.step v=2
Fourier components of I(load)
DC component:0.00101845

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 1.000e+03 5.250e+00 1.000e+00 179.95° 0.00°
2 2.000e+03 2.259e-04 4.303e-05 82.39° -97.56°
3 3.000e+03 4.718e-03 8.987e-04 -166.44° -346.38°
4 4.000e+03 3.584e-04 6.827e-05 -65.00° -244.94°
5 5.000e+03 7.933e-05 1.511e-05 169.36° -10.58°
6 6.000e+03 7.918e-05 1.508e-05 122.42° -57.53°
7 7.000e+03 6.673e-05 1.271e-05 -96.63° -276.58°
8 8.000e+03 8.248e-05 1.571e-05 134.77° -45.18°
9 9.000e+03 1.243e-04 2.368e-05 51.48° -128.47°
Total Harmonic Distortion: 0.090313%