The AMNESIS amp: a good amplifier, like a gentleman, has no memory.

[maxlorenz]

The Сap comp of Miller limits the spectrum for the next stage, and the RC phase twists approximately in the range of 25-60 degrees at a frequency corresponding to its time constant, and the entire over spectrum goes to the next stage, if it does not have enough frequency properties, it simply turns the phase and the result is positive feedback.

Thanks dear Hennady.
Every day we learn something....

The stability question is one of the most difficult to comprehend and tame, for we, non-instructed amateurs....

Best wishes,
M.

 

[Hennady Kovalsky]

The stability question is one of the most difficult to comprehend and tame, for we, non-instructed amateurs....

so it’s not so difficult - one of the rules is that, a compensation capacitor in parallel with the common NFB resistor - you can immediately say that the amplifier is overcompensated, and that this is very bad for the sound, due to the complex nature of the real load.
What I constantly see in this topic are models with such a compensation capacitor - it becomes sad....

 

[maxlorenz]

Hi guys,

The other day I stumbled upon a video explaining "Cascode Compensation" and it was very interesting...
I made some simulations with a "double cascode Comp." and it improved the safety margin (a lot, in my unneducated POV), at the cost of slower response and lower BW.
What do the Wise think about this technique?

Cheers,
M.

 

[STEP RESPONSE]

Hi Maxlorenz and everyone else,
It is always interesting to improve Quality with suitable solutions.
Since I have "embraced" a full-balanced Circlotron with a Sziklai finite structure and negative output resistance - I use the recommendation of Willy Studer and Rupert Neeve.
This means: Medium-power (driver) transistors at the input and preamp with enhanced Class A to eliminate Memory Distortion!!
The amp is now LIVE and I can post the schematic - if there is serious interest....

With respect

Trifonovaudio

 

[Alexandre]

Hi, could you point us to sources for these recommendations? I'd like to read, should be interesting.
Thanks,
Alex

 

[EdGr]

maxlorenz - R37 applying a signal to one side of the differential makes the differential less good. This does not seem like a working way to bring down the loop gain.
Ed

 

[maxlorenz]

Thanks guys for your replies.
I will consider them.

Dear Mr. Trifonov,
I congratulate you for your success.
I must try your tips in simulation first.

Happy Solstice.
M.

 

[Alexandre]

Hi Maxlorenz and everyone else,
It is always interesting to improve Quality with suitable solutions.
Since I have "embraced" a full-balanced Circlotron with a Sziklai finite structure and negative output resistance - I use the recommendation of Willy Studer and Rupert Neeve.
This means: Medium-power (driver) transistors at the input and preamp with enhanced Class A to eliminate Memory Distortion!!
The amp is now LIVE and I can post the schematic - if there is serious interest....

With respect

Trifonovaudio

Hello, it would be very interesting to read Studer and/or Neve, if there is material available...
Thanks,
Alex

 

[maxlorenz]

I AM having fun with my new and Free cell-phone: checking out how does it record.....
Here, some recent uploads to my first channel:

I hope it sounds decent....
Cheers M.

PS: one or two may have a delay in processing....

 

[maxlorenz]

One of them had problems. I reloaded the OTARI one but I AM not happy with it....much noise and wrong eq. settings...

I may post a better one and delete this...

 

[maxlorenz]

Another try, same cell-phone....

Cheers,
M.

 

[maxlorenz]

Hi guys.
I've been entertained with my tape projects so I had to pospone experiments with the Amnesis with Hawksford CCS.
Anyway, here I post a couple of videos: the first with the Amnesis-Mosfet and the second with Amnesis-VFET.
I real life, the VFET amp has a transparency and naturalness that is hard to improve.

I hope you like them,
Cheers,
M.