The diyAudio First Watt M2x

[PaulInWA]

I see some listed on eBay but I have no idea how to tell if they are authentic. It is crazy how many parts in the M2x build are out of stock. I'm going to end up order from 3 different places and still having to make substitutions.

 

[AudioSan]

I got all my parts from Mouser just yesterday. Exept for the output devices that i got a couple of weeks ago. Still waiting for the Edcor transformers. There have been some covid delays from USA.

 

[PaulInWA]

Mouser didn't have the MOSFETs or the MV5075C LEDs. They also didn't have the specified J112 JFET and I had to make substitutions for several of the capacitors.

 

[Vunce]

PaulInWA,

Check Newark.com

Why turn to eBay when Newark has plenty of IRFP240’s?
Also check there for the other out of stock items.

 

[Mark Johnson]

Here are some places with IRFP240 on the shelf, in stock, ready to ship: link 1

Here are some places with MV5075C in stock: link 2

Here are some places with J112 in stock: link 3

You can also use the helpful website named findchips dot com .

_

 

[PaulInWA]

Thanks Mark. Very helpful.

 

[dliscomb]

Why turn to eBay when Newark has plenty of IRFP240’s?

YMMV, but my very limited experience with Newark is not good.

• Connectors arrived in a padded flat pak, but the tabs were broken off. All of them.
• Components ordered and arrived, but the quantity was off. Even the pick slip confirmed that I didn't fat-finger the order.

I will order from Newark in the future, but only because I haven't ordered from them much, and only if they are the last resort.

Kind regards,
Drew

 

[Ryssen]

Been soldering the Black forrest pcbs.
And I wonder what should the voltage after the 5w 300 ohms resistors be?
On one channel I get (with my labsupply on +-25v) +25v and -12,5 v.
And on the other -25v and +12,5v.
There is a sinus wave.

 

[Ryssen]

I guess it should be 12,5v...

 

[cubicincher]

to Rysssen

Hello Ake,


yes, you should arrive at around +-10.5 V DC to +-12 V.

25 V DC on one of your rails is definitively too high. The 300 Ohm resistor should burn that voltage down to the before mentioned values. And V DC should be symmetrical on positive and negative side.



Greets
Dirk

 

[Ryssen]

I now know what I did wrong...I got to messaure on the other side of that resistor (PCB side)...then it is 11v on both possitive and negative.

 

[cubicincher]

to Ryssen

Hello Ake,


that sounds much better....


Cheers
Dirk

 

[Ryssen]

How much voltage p-p is neded to drive the M2x to full output?

 

[Mark Johnson]

Same as the First Watt M2. Please download the M2 manual from the First Watt website and enjoy reading the table of specifications contained within (page 10). Your question, and numerous others, are answered there.

 

[Ryssen]

Thanks for putting me in the right direction.
It says 3v= rated power,but is it RMS or p-p?

 

[poseidonsvoice]

Ryssen,

It's RMS.

The gain of this amplifier is only 14dB or 5X.

Hope that helps!

Best,
Anand.

 

[Ryssen]

Anyone got 1 extra Black forest pcb to sell to me?

 

[Ryssen]

Anyone got 1 extra Black forest pcb to sell to me?

I got a hold of a pair..

 

[Ryssen]

When I´d bolted the mainboards to the heatsinks I se this small squared solder pads under the IPS with a symbol that they should be soldered together?
Should they?

 

[TungstenAudio]

If you look at the underside of the board, you will see that the traces are already connected between those points. You may add the small jumpers if you like, but they are not mandatory.