Unusual amp from 1987

[stanislav1957]

I do not put a capacitor in the filter at the input of the amplifier.
The achieved speed is enough, the main thing is the linearity of the amplifier . A cleaner sound

 

[minek123]

Perhaps C10 in Maxim's schematic counts here and slows the amp down?

 

[stanislav1957]

Perhaps C10 in Maxim's schematic counts here and slows the amp down?

No. This does not affect the speed, only affects the frequency of the single gain.

 

[minek123]

In a Microcap with tl071.The speed dropped significantly.
It's a pity I'm not good at lts

What happens if you try LT1056?

 

[stanislav1957]

What happens if you try LT1056?

the correction values matched yours. there is no capacitance at the input of the amplifier.

 

[minek123]

I agree that achieved slew rate is sufficient, that's not why I'm trying to squeeze more speed from it... it's just a game. To me all these amps sound the same anyway 🙂
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Согласен, что достигнутой скорости нарастания вполне достаточно, не поэтому пытаюсь выжать из нее побольше скорости ... это просто игра. Для меня все эти усилители все равно звучат одинаково 🙂

 

[minek123]

Песня про зайцев - YouTube

А нам всё равно

 

[stanislav1957]

we will strive for better ideals . To a beautiful sound that we haven't reached yet .
К прекрасному далеко!
??????? ??????? ??? ????? ?. ?. ??????- ?????????? ?????? - 10.12.2019 - YouTube

 

[minek123]

Here is double folded cascode VAS - gives twice the speed of normal LMK VAS.
Perhaps it will improve your amp?

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Вот каскод VAS, сложенный вдвое - дает вдвое большую скорость, чем обычный LMK VAS. Может, это улучшит твой усилок?

 

[stanislav1957]

Parallelized the current sources with alternating current .quasi-symmetries. Very interesting

 

[minek123]

10nF cap needed for taming square waves...

 

[stanislav1957]

I'll think about it. I'm done for today. I need to rest .

 

[minek123]

I think it can use the same biasing from LEDs - this configurations works the same:
We can save one resistor..

 

[stanislav1957]

ОК

 

[stanislav1957]

By introducing an emitter follower, the speed can be doubled.The printed circuit board is easier to get

 

[minek123]

I thought you went to sleep 🙂

I know how this is going to end - you are going to add a coil to it...

 

[stanislav1957]

won't be able to sleep.
The clip is not bad.
The decision was long ago, but overlooked.

 

[stanislav1957]

I thought you went to sleep 🙂

I know how this is going to end - you are going to add a coil to it...

Do not use the coil. .kg still doesn't change.If the loop gain was greater, then the result would be, and so there is no sense.
In the model, the distortion is very low.Very small.

 

[minek123]

That's the lowest Thd, and best frequency spectrum so far.
Slew rate: 50V/us - very respectable.
Results here for 1kHz and 10kHz input.

Correction: Zener resistors (R3/R4) should be 3k. Zener current is too high with 1k5 values.

 

[minek123]

This version, with double folded VAS, lowers the floor of FFT graph by a few decibels, and allows for (small) increase in speed.
Please check; not sure if it's worth it...
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Эта версия с двойным свернутым VAS снижает нижнюю границу графика БПФ на несколько децибел и позволяет (небольшое) увеличение скорости. Пожалуйста, проверьте; не уверен, стоит ли оно того ...