M³ amplifier build discussions thread

[amb]

Now that people are beginning to receive their boards and parts, it's good time to close out the "M³ project announcement" thread and start anew here.

Have fun building your new amps!

Must-read links for builders:
amb's M³ site
Morsel's M³ site

[MisterX]

Have fun building your new amps!

Can't, they are not here yet.

Do you know of a source for the Wima MKS-2 1uF C2/C8's?
Mouser doesn't stock them and as such you have to order 110 of them.
I am gonna order them anyhow but the other people might like to know of a source for them

If you want to split half the order email me.

[amb]

Originally Posted by MisterX

Do you know of a source for the Wima MKS-2 1uF C2/C8's?

Does it have to be Wima? You can substitute with Vishay-Roederstein MKT1817 1uF box caps, mouser part #75-MKT1817510064.

Edit: I just checked and Mouser has Wima MKS-2 1uF 63V 10% in stock:
Mouser #505-MKS21/63/10, minimum order quantity is 10, but since you need 9 per board, it's not a problem. Also, they have Wima MKS-2 1uF 100V 10% #505-MKS21/100/10 in stock and available in single quantities (or multiples of 10/100/500, etc).

[MisterX]

Nope... they don't have to be wimas by no stretch of the imagination.

Do you know how that works though?

Originally Posted by buyers first question

I don't want those green looking caps can you replace them?

[ub312g0d]

In AMB's MMM building guide it shows that the rca's ground must be connected to the volume pot via the case. Im planning on a wooden case so was wondering if it would be necesary to connect the two inside of the case?

[MisterX]

As I rech over ond check the status of the fume extractor I have to wonder WTH was I thinking....
Thanks for reminding me that 63 volt caps also fit.

[amb]

I don't want those green looking caps can you replace them?

LOL.

[amb]

Originally Posted by ub312g0d

In AMB's MMM building guide it shows that the rca's ground must be connected to the volume pot via the case. Im planning on a wooden case so was wondering if it would be necesary to connect the two inside of the case?

The volume pot's body needs to be grounded or else you'll induce hum when you touch the volume knob. If your front panel isn't metal to connect the pot body to the signal ground, then you should add a small length of wire, secure it to the pot body (loosen one of the ALPs pot's screws on the back and hook the wire onto it before tightening it again, then solder the other end to one of the IG pads nearby).

[phobus]

0.100" 2-circuit pin header, plug and crimp terminals

I'm not sure what to order from digikey. Can anyone help me with part numbers please?

Thanks

[amb]

Originally Posted by phobus

I'm not sure what to order from digikey. Can anyone help me with part numbers please?

Look further down the parts list page, under "Connectors", and it shows you the options. You would use these if you want to be able to unplug all connections and remove the PCB without desoldering any wires. If this is not an issue then you could simply solder the wires directly to the PCB pads.

[Edwood]

LOL, are the Wima MKS-2's really that much better than the Vishay Roederstein's?


Other than being more color coordinated with Cerafines?

-Ed

[Syzygies]

Anyone who wandered into this thread by accident, start here:

Amb's M³ Page
Morsel's M³ Page

So, any reason those of us who want to put off dealing with the power supply issue for now can't just use a series of two lead acid batteries? RadioShack sells tiny ones, my barbeque pit computer uses a "lawn & garden" battery, sort of a 1/3 size car battery.

Wouldn't this sound better than all but the best regulated supplies? Or is there a current issue?

I'd have to check, a fully charged pair might exceed 27 volts. That's an issue with many op amps, as amb notes.

(There is a spectrum for lead acid batteries. Car batteries put out amazing amounts of current briefly to start the engine, but don't like repeatedly being fully drained. Marine batteries are in between, golf cart batteries are the other extreme, like to be taken fully down and back up hundreds of times. Has to do with internal distance between plates. My dad uses golf cart batteries for his solar panels on his summer cabin.)

[stadams]

Is anyone working on a BOM that includes all the parts recommendations by amb? If there was a general consensus on suppliers, maybe narrowing it down to three or four, the BOM would not be to bad. An interactive Excel spreadsheet would be nice. And for those lucky enough to not have Excel maybe a .pdf file would be nice. Although you would have to calculate the prices by hand when using the .pdf file.

Later,

[ub312g0d]

syzygies, I cant see any reason why 2 sealed lead batteries in series. Im not sure about how much power the little rat shack ones have in them but any of the larger sized ones would be nice for testing and act like the perfect power supply. Seems like a decent solution for testing and such anyway. Hell, It would even be "portable" if you did. Just put it all in a backpack and hope the straps dont get ripped off.
Of course if they're putting out that much voltage fully charged just watch what opamps you put in there, but of course you mentioned that already.

[fool]

Originally Posted by Syzygies

Anyone who wandered into this thread by accident, start here:

Amb's M³ Page
Morsel's M³ Page

Thanks! Until this thread I didn't realized the MMM project had progressed this far.

-fool