Official M2 schematic

[Nelson Pass]

For all the Greedy Boyz,

The M2 officially discontinued, here is the official schematic, assuming that
it has not otherwise been posted.

In particular note the interesting bias circuit that you can use elsewhere.

😎

 

[2 picoDumbs]

You are extremely generous. Thank you Nelson.
I will stick it on the wall so I can study it.

 

[2 picoDumbs]

The value of R6 and R7 seems too large.

 

[2 picoDumbs]

Lm385 is a 3 pin device.
Unless one of the legs is shorted then I'm completely lost. Hahaha

 

[grimberg]

Check the Dumbmeter...

The Dumbmeter you used to assess yourself must be overdue for calibration.

🙂

 

[2 picoDumbs]

Yeah, I think I'm out by 2 orders of magnitude. It should 0.02 Picodumbs

 

[2 picoDumbs]

Now that I think about it a larger number would make more sense. Less dumb means more smart.
I think I was reading the intelligence meter not the dumb meter. It must be 0.02 PicoSmarts (not very smart).
I'll have a brainwave later and redeem myself for this lack of intelligence.

 

[2 picoDumbs]

Ok. If you short out the adjusting pin thing with the negative thing you get a 1.24V reference.
Need to think about that.

 

[stoN_Cold]

For all the Greedy Boyz,

Voltage PSU?

 

[kacernator]

Voltage PSU?

Still the same +- 25V.

 

[crt]

Thank you Papa

 

[2 picoDumbs]

Still the same +- 25V.

The M2 is an Amp that runs off 22 to 24V rails

 

[Zen Mod]

Q6 and Q7 are LM385-1.2

D1,D2,D3 are 1N4148

Q5 4N35

yeah , stick it to the wall and enjoy sheer beauty

 

[2 picoDumbs]

Q6 and Q7 are LM385-1.2

So I got that part right then. Amazing.
Hahahaha

 

[2 picoDumbs]

I'm thinking it might be beneficial to make R6 45k, assuming P1 sets DC Offset

 

[stoN_Cold]

Still the same +- 25V.

Thx.

 

[Zen Mod]

I'm thinking it might be beneficial to make R6 45k, assuming P1 sets DC Offset

count on Ugs difference between N and P mosfets , for same current

however , as with all Papa's schematics - count on fact that he's usually taking parts from pre-selected drawers** , so changing any appropriate resistor (say for + or - 10%) if needed on the fly, is trivial thing to him

(one of) purpose(s) of all these schematics thrown on all of us in past few decades is pretty much the same - to same things became trivial to us , too

** he didn't said that , but logic dictates the same, for most cases ;
however , upon completing the amp , if output offset stubbornly stays negative , decrease R6 ; if it stays positive , decrease R7 ; I believe I needed 39K for one , but can't remember which ; even though I used FQP/FQN parts , Geschenk by my älterer Bruder Generg

 

[h_a]

Amazing little circuit and very elegant!

Thanks Nelson!!

 

[wdecho]

Q6 and Q7 are LM385-1.2

D1,D2,D3 are 1N4148

Q5 4N35

yeah , stick it to the wall and enjoy sheer beauty

Thanks Zen, I was fixing to ask about the transistors and diodes. What does the red square around Q5 and diode refer to?

Edit, After googling the 4N35 I see it is a 6 pin Optocoupler. Disregard question.

 

[2 picoDumbs]

Thanks Zen, I was fixing to ask about the transistors and diodes. What does the red square around Q5 and diode refer to?

Optocoupler device