Nelson Pass M2

[prasi]

Here is a version of Mr. Pass M2 amp with 2SK /2SJ fets.

resistors and some caps are smd 1210 .

if anyone wants i can share eagle files / gerbers.

 

[nicoch58]

nice

 

[Zen Mod]

nice

heavy copper and you're good

 

[Guiness]

yes please... give me another reason to practice my SMD soldering

 

[poseidonsvoice]

Yes please! Your MOFO pcb designs were gorgeous, still using them!

Best,
Anand.

 

[Dennis Hui]

Very nice contribution!

 

[Berny]

Looks good!

 

[Mark Johnson]

thought #1: Are the 6.35mm FastOn blade connectors at top (image 1 below), spaced far enough apart? Builders probably want enough blade-to-blade distance so they are able to use insulated female connectors (images 2 and 3) on the ends of the wires.

thought #2: Might want to investigate Blasphemous Heresy . Many DIY builders of M2 have found it indispensable.


_

 

[prasi]

Hi Mark,
1. Yes, the distance is sufficient, silk edge to edge distance is 10.16 mm. But I can leave additional 0.508 mm gap easily(attached). center hole is a big one (~2mm) to solder direct wire..
2. I didnt understand...could you elaborate or point me?

 

[MEPER]

I think 2 is related to 47k R6 to lower it to e.g. 37k in order to be sure to be able to offset the amp to 0V DC.....? .....I used that trick myself.....up front....did not try first with 47k....but went straight to the lower value.....

 

[MEPER]

.....I am not sure about the value of R6.....but lower it was......

 

[bullittstang]

MEPER is right, that R6 was lowered to 37k and the trimmer increased from 5k to 20k. This allows more resistance possibilities to compensate for negative offset, which apparently can be seen with the stock R6/R7 at 47k and trimmer of 5k.
It is blasphemy though - so maybe best to leave the artwork original to Nelson and include a note in the BOM or in this thread, if someone can't stand a negative offset?

Great looking board by the way - always amazed how small these PCBs can get, with SMD parts.

 

[dantwomey]

 

[Mark Johnson]

Google knows all about Blasphemous Heresy and is VERY GLAD to explain it to you:

(link)

 

[prasi]

Google is too big..., but thank you for pointing me in right direction in google archives... blasphemous and heresy are new words for a guy from India and didn't know how to connect those to NP M2 amp. Sorry...

 

[poseidonsvoice]

Prasi,

Thanks for the contributions and updates. I am looking forward to building a version of the M2 with an SMD twist (in the right places!).

The “blasphemy” is right here (Section 3):

https://www.diyaudio.com/forums/pass-labs/321925-diyaudio-watt-m2x.html#post5416402

He/She doesn’t want credit for it though

Best,
Anand.

 

[codyt]

Great looking board! I would certainly be interested in gerber. Side note - I like that the center hole is slightly bigger for bare wire on the QC connections.

 

[prasi]

Gerbers- M2

Thanks everyone.. here is the 'art work' and gerbers. Regarding R6/P1, builders can choose what to use.

Took my own time to make it all "curvy"
All the best for your build..

regards
prasi

 

[prasi]

3D rendering of assembly for illustration

 

[codyt]

Very nice! I’m really liking a mix of THT and SMD (on bottom). Was there a note about potential UMS alignments in one of your screenshots?

*edit* can you describe what you meant by ‘can be 120mm away to use UMS’?