Dx Optimus is being prepared... dynamic bias.. Class A to AB

[destroyer X]

having more watts into class A.... bias is controled dinamically receiving audio from output and controlling the VBE multiplier resistance (voltage drop).

I am just starting...it is working into simulator and i have to study to decide the stand by current and to adjust the decreasing.... say... to decide what power will return to AB mode.

Well.... it is just a simulating monster...working...but cannot guarantee quality before construct.

Next days i will be studying using simulator and calculator machine...and hate that part...and they the good work will start.

I will publish IF, result good.... It will be something that remembers Dx Standard and the HRII..... around 50 watts into 8 ohms.

No... i have not discover nothing ...this was used by JVC down the eigthies...i will just adjust, adapt, match, tweak and make it work..just that!

regards,

Carlos

[destroyer X]

we gonna see if this will result good or a big sheet.... of papper filled with sketches.

regards,

Carlos

[lm324]

Hi carlos,


The Dx as "Super A" Gradiente of the past! Let's wait and see ...

Good Lock.

Rogério

[destroyer X]

and my Dx HR II and Dx Standard mixed all together.

This idea was called Super A.... and it just control stand by bias dinamically...bias is increased till you reach 5 watts RMS (this is adjustable tweaking the circuit) and then return to the standard Class AB biasing.

But..my Dx Amplifier uses "increased volume triggered bias level"... already much more bias than other amplifiers.... the efficiency is lower than others, but it is an increased tipo of class AB amplifier when you increase volume to 10 watts and more.

The idea is not mine, the circuit i am tweaking is not mine.... as i said was JVC...and those early days of brazilian audio industry, Gradiente had association with JVC and used to build licenced JVC schematics...so..JVC and Gradiente are not different.

The circuit, the idea is not mine..but the adjustment i will give to it will be mine, and this will make the difference.

Also my amplifiers does not sound alike Gradiente (not enougth high frequencies to my taste)..... i hope!

This one will sound my way.... will be brigth into trebles alike HRII and will not have any artificial high frequency increasing device.... no trick capacitor.

ahahahha.

regards,

Carlos

[destroyer X]

With all this output level?

regards,

Carlos

[destroyer X]

But i am satisfied...waveshapes from 1 hertz to 30 kilohertz are very good.... slew rate seems very good into 20 kilohertz.

It is turning good.... slowly will be better.

Picture using shirt....celebration.... Optimus have just born.

regards,

Carlos

[destroyer X]

Mine is Dx OptimUs....using U..... latim name.... optiMOS maybe it means optimus plus MOS.

Well... i do not know..... i have not watched Randy schematic.

Mine is Dx....base into the Dx Standard and HRII... a very different circuit.

Name here is "DX OPTIMUS"

Observe from Slone home page...his amplifier is OPTI-MOS... mine is Dx Optimized bias amplifier.

regards,

Carlos

[fab]

Originally posted by destroyer X

...No... i have not discover nothing ...this was used by JVC down the eigthies...i will just adjust, adapt, match, tweak and make it work..just that!

regards,

Carlos

Hi Carlos,

The JVC Super A integrated amplifier was the first amplifer I bought in 1982. I had the 40Wrms version. At the time I did not have the good source and good speaker to really appreciate its sound. When I made my quasi complementary V-MOS DIY amp, it already sounded more detailed than my JVC...

However, I suppose that you can have your own design with the Super A principle that can be quite different than the JVC and hopefully even better

Good luck and keep us posted.

[Lumba Ogir]

Charlie, maybe you are celebrating too soon, wait and see how optimus it is in practice.

[destroyer X]

We never know till we listen.

thank you,

regards,

Carlos

.................................................. ................................................

I am listening the Dx Standard.... the young kid...the first i have made, and it is not mufled...so.... not my speaker and not my ears.... some amplifier really sounds mufled compared with others...if you do not compare..you may listen your life long without realise that.

Carlos