Official M2 schematic

[Zen Mod]

OK , considering it's typo , there is still hope to become .......... one thinking in engineering way

(perfectly OK with me , considering that I'm also never going to became one )

you got the recipe how to cure output offset , now just find proper value for adequate resistor position

keep it up to 30mV , either pos. or neg.

 

[generg]

mine goes damn good down , considering that I have 15" Tann from all way down (to up ) , with Beyma 15" helper (OB , referenced few posts up)

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

though , my M2 is dual mono , properly wired , 250VA Donut with 4x33mF per channel

I build my M2 with dual mono too and I had the opportunity to compare it with an original from late permaneder and it was clear that this is a way to have much more power in the bass.

 

[nicoch58]

(Beyma 8R + 2R35 resistor in series )

Hi ZM what % rise the Qes the 2R35 ? the beyma model ?
grazie e gas a martello

 

[Zen Mod]

dunno really

I set it by ear ; as you can see from pictures of my setup, it's pretty unique , so no much use of pre-thinking

 

[drjbf1]

Hi ZM what % rise the Qes the 2R35 ? the beyma model ?

Try this: Qes(new) = Qes * ((2R35 + Re) / Re)

Qts calculated normal way with Qes(new) // Qms

 

[nicoch58]

+1 if ZM post the model

 

[Zen Mod]

Beyma SM115/N

be sure that size of OB is adequate for your specific case

 

[wdecho]

I have not been able to tear myself away from this amplifier long enough to do any A/B comparisons but I do want to say something about this amp. I have built 4 of the Firstwatt clones and I am loving this amp like none of the rest. This is one seriously good amp. Last year I also built 3 SET's and one Pentode amp but as I have said I cannot take time away from listening to it to do any comparisons.

It may be that I love the sound of an SET with my speakers. If you like the SET sound this amp will appeal to you.

 

[Zen Mod]

.

 

[wdecho]

I see you are in agreement about this amp mighty Zen.

 

[brianco]

Well, what did you expect?
...what has ZM being telling us for so long?
..you see he, the mighty one, is correct in his advice....now and zen.

 

[wdecho]

But being an unofficial adopted son he was one of lucky few that were able to build this amp until now. The rest of us had to wait years to see the schematic or be fortunate to have the funds to buy a commercially built one. I agree that it is hard for me to understand how Nelson could discontinue production of this amp. I bow again to his generosity.

 

[Zen Mod]

naah

ZM being in Papa's Disgrace for Eternity , and longer ........

 

[Danger Mouse]

...I have built 4 of the Firstwatt clones and I am loving this amp like none of the rest.

Which models was this 4 FW amps?

 

[Dennis Hui]

I agree that it is hard for me to understand how Nelson could discontinue production of this amp. I bow again to his generosity.

Agreed. It's a wonderful gift to the diy community. I wonder if Papa's
discontinuing it simply because he doesn't have enough time to build
it anymore.

Dennis

 

[wdecho]

Which models was this 4 FW amps?

My first was an Aleph 30, then I built a SE BA3, then the F6 and now the M2. All are exceptional amps but all have there own unique sound.

 

[Ryssen]

Hmmm, does it matter how the trafo is turned?
Watching this post http://www.diyaudio.com/forums/pass-labs/281520-official-m2-schematic-49.html#post4578853
it doesn´t matter or?

 

[Zen Mod]

you got it wrong

it's pretty much important how trafo is turned

in fact , due to pinout , you can't mount it in wrong way

 

[wdecho]

Two pins are closer together than the rest and also instructions on which pin is #1 comes with the transformers in cause you point to point build.

 

[grimberg]

... in cause you point to point build.

I don't think he will. He happens to have a pair of nice PCBs, just like yours.