DIY Passlabs First Watt M2

Been keeping this under my bed for around 3 years ago when Nelson Pass release the M2 schematic. Today, I have dig out the extras to build one M2 without the obsoleted Jfet J74/k170 but using a composited loop opamp to serve as an buffer for the Edcor. Ideas was inspired from diyaudio. But I will be adding regulators for the opamps, and use the LME49990 + LME49610 as buffer. 

For maximum syokness, the casing is fully alloy casing and 1:1 Pass labs clone 

Stay tune for my PCB drawing, I will post the entire gerber files here if any of you interested to build one too.

Nice!   Keep us posted on your project. Thanks

Updated with some schematics here, the LDO for the +/-15V is using TPS7A4701 and TPS7A3301.
The goal is to have an ultra low noise buffer couple with M2 sound signature. 

For the PCB, I will not follow the reference M2 layout. I will try to re-layout and reduce as much as flying wires needed inside the casing. 


Low Noise Regulator Stage:



Buffer Stage:




M2 Output Stage:

Updated draft PCB layout. 

1. Left & Right will be sharing only one PCB.
2. No additional PCB for capacitor Bank. 
3. Mono-block Design.
4. Straight forward wiring, no fly-wire here and there.
5. Star-ground layout for separating input and output ground.
6. Large Ground plane.

That's a very nice PCB layout work.

Just have a long discussion with an old friend this afternoon about this M2 clone, he saids its better  to follow back pass labs layout so that it will make us feel more pass alike. I agree on that because Hifi is not just hearing, it's about visual sense too. 

I will update and place the CRC power supply at the middle, individual left and right channel PCB, to make it look like Pass kitchen amplifier.

Just managed to build it up today!

Tested an whole afternoon with this mighty Firstwatt krone, I can't stop to put a smile on my face. My Xero never sounds sooo good soo special before, I like it much more comparing with the firstwatts F5 that I have built many years ago. 


The High
If you ever heard to Firstwatts F5, you will amazed by the solid and bright high frequency band. But with this M2, the Leema Xero becomes a whole different beast, it sounds so airy and transparent that you hardly feel that the sounds is coming from this speaker. Especially on the high frequency band, you will heard a lot of sparkling micro details.

In short, if you are listening to a female vocalist song, the F5 will awake you with it's solid and bright characteristic, but the M2 will put you into sleep with it's airy and heavenly transparent characteristic. 

The Low 
The F5 gives a very solid and punchy bass, but this M2 drives it in a completely different fashion, it fills the room with the airy bass, make the sound stage way much wider than before. 

Audition is available if any of you really interested to play with it.

chong, 
Congratulations. very nice work.
I will take up the offer to audition when I am in KL .
kp93300

Sure sir, welcome to drop by!

Hi,

Can you tell me where you got this chassis?

Thanks,

Greg