Official M2 schematic

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#3,482
They are. Aleph J Iq is 1.5 - 2A per side. ACA supply is 5A - good for two AMP PCB's.

My Aleph J runs at Iq = 4A total. I think M2 runs at lower Iq (...?)

I tested the ACA's Meanwells at 4A with a resistive load, and the voltage sag was in the range of few millivolts (!!) - exceptional power supply.
 
#3,485
In my experience M2 works well with SMPS. I use Vicor in separate chassis, not Meanwell but same concept of course.

I have no scientific evidence, but my instinct tells me that the Iron (the gain structure of the amp) in the M2 reduces the HF ripple. win-win?
 
#3,488
I've had the necessary parts for years and just last week I decided to build up a couple of channels to play with.
I'm wiring p2p, kind of M2x style, mainly because all I have on hand are small project boards buy having read the M2x thread, I'm also happy with the utility aspect.
My first front-end board is complete, using closely a matched lsk/lsj pair from the diyaudio store (within .02ma).
I used a Bourns 20R pot in place of the Jfet source resistors on a whim and have powered the board up and zeroed the offset at pin 7.
Everything looks good to me but I just wanted to verify...
The pot, after zeroing offset is at 13R5 for the 170 and 6R5 for the 74. Does this sound about right?

D
 
#3,492
chermann said:
yes ...but i prefer a SMPS with dual rail if i need it because i do not know how the GND is set at every ACA SMPS and what voltage potential you get if you build it together:
V+ GND V-
Click to expand...

If you remove the cover of the supply you will see that the supply is surrounded by a metal shield that is connected to the supply's earth (and PE).
So to connect two power supplies like this won't work if both supplies protective earths is used.
 
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#3,495
Cant get my DC offset less than 40 mv on one channel and 140 mv on the other. There is no hum and the amp seems to sound fine. What controls the DC offset besides the pots? Total noob at electronics just a warning lol. Listened for an hour and my drivers of my test speakers are still alive.
 
#3,498
I'm busy populating Tea-bag's boards and went for the "R3, R4 hack" as described in post #2592.

But I'm unsure how to adjust the Bourns trimmer. Do I use a DMM? With the amp on or off? Need some guidance please.

Vu8DrDX.jpg
 
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