The diyAudio First Watt M2x

I live in the San Jose, California metropolitan area which Google tells me with great confidence, includes 1.9 million people.

I visited an extremely high-end jeweler in one of the fancy suburbs and handed over an M2X motherboard + bolts + washers + nuts + daughterboard. I asked: How much would it cost to have this entire signal path plated with (a) gold; (b) silver; (c) rhodium; (d) chromium.

The answer was: nobody in California will do that for you. Nobody. Your hardware needs to be plated with nickel first, and only then can it subsequently be plated with any of the options (a) thru (d) above.

But the one company in California who used to perform that type of service, stopped. The old man retired and his kids are not interested in pursuing that line of business any more.

Perhaps other diyAudio members living in other states, might have better luck if they shopped for precious metal plating of M2X hardware. I tried it, myself, and got nowhere.

I'm in SoCal. There is a guy in Newport Beach that might do it. Let me get all my parts in order, I will go ask him, and report back...
 
Well, that is a very thoughtful and thorough list! I'll take a look at it carefully.

Although, for me, it's usually best if EVERYTHING comes from the same store.

I have just finished a minor purchase at Mouser and I had to battle through 3 different mails where they expected me to fill government forms of use intent, export details and credentials, exporting company, recipient company.

"Well, it's for personal use!"... More forms, disclaimers, waivers.

Digikey directly told me that a hotel cannot be my 'main' address :O .

Thanks again, I'll match them to my own notes, really appreciate it.

Rafa.

Ouch, that sucks. Folks got really touchy about certain tech after 911 :(

For the topic of plating.
Plated hardware is usually made slightly undersized so the plating will bring it up to size. So if you buy screws with a good fit, they might not fit after plating, especially if the plating is thick enough to be meaningful. Silver oxidizes very fast, so the screw needs to be tight enough to make an airtight seal - this will be problem (more like impossible) with tiny brass screws. I would trust 2mm banana plugs and sockets before I would trust a silver plated brass screw. The problem is the ones I could find where pretty expensive. The coating on the aluminum standoffs called for in the BOM is supposed to be conductive (but really only if properly done), so unless you want to remove the board every few months to clean the contacts, silver will be inferior. I expect the ones sold by Mouser are intended specifically for this purpose, so there is a good chance they have a grade 3 coating.

The ideal solution is to use a ribbon connector, redesign the boards so they plug in (like the way am m.2 drive does), or find a source for good pin and socket standoffs.

I am seriously considering relocating the input boards so they attach to the top cover and drop wires or a ribbon to the main board. That way the board could be swapped from the outside (prolly put a cage over it), and I could just find something gold plated to use for mounting pads. I have a well equipped machine shop, so I have many options.
 
Is the PSU PCB in the shop the go for the M2x?
I will be using 2x bridge rectifiers and using the PSU PCBs for caps and resistors.
Also are the 15,000 uF caps OK for this build. Thinking of putting the PSU on a Riser too.
TIA
NOOB steve (my first power amp build).

Also is it a good idea to use the soft start and speaker protection?
 
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Is the PSU PCB in the shop the go for the M2x?
I will be using 2x bridge rectifiers and using the PSU PCBs for caps and resistors.
Also are the 15,000 uF caps OK for this build. Thinking of putting the PSU on a Riser too.
TIA
NOOB steve (my first power amp build).

Also is it a good idea to use the soft start and speaker protection?

Hi Batty, yes the psu pcb from the shop can be used. Bridge rectifiers are ok to use, it’s actually what many of the builders here including myself have used. 15k uf caps x8 are good, as a matter of fact I believe that they are the size used in the stock First Watt amps and standard psu designed by Nelson Pass.

I would suggest that you read the entire M2 and M2x threads before your build your amp. Yes, it’s a lot of reading but they will answer pretty much all of your questions or issues you may encounter during your build, and may even offer some part substitutions or suggestions so you only need to order your parts once. Doing so for both my Aleph J and M2 builds made the whole process much easier and stress free.

As always if you have an questions someone will be more than happy to lend a hand. I was a noob once, and actually still consider myself one. Reading and re-reading the threads is a must for a successful build.

Here’s a pic of the M2x I just completed. You’ll see all of the parts you just inquired about.
 

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Finally back in business - ended up replacing all of the active elements on the board - still not sure how or what was specifically causing this behavior but I am very glad to have a working amp back up and running.



will keep it in the test bed before moving up into my system.

thanks to all again and a special thanks to @flocchini for having a spare FET that he graciously sent me.

..dB
 
OK, my M2 is up and running but I think something is amiss. My output volume is not very loud. I'm using a B1 preamp and at full volume the output is moderately loud. I've also tried hooking the source directly to the amp with the same result. My speakers are 101db so, I feel like they should be much louder. My F5 did not have this issue. I'm measuring around .620 across both .47 ohm resistors on each channel.
 
OK, my M2 is up and running but I think something is amiss. My output volume is not very loud. I'm using a B1 preamp and at full volume the output is moderately loud. I've also tried hooking the source directly to the amp with the same result. My speakers are 101db so, I feel like they should be much louder. My F5 did not have this issue. I'm measuring around .620 across both .47 ohm resistors on each channel.

Gain should be about the same as the F5. What daughter card are you using and what is your source?