W A R N I N G !

W A R N I N G !

This page is full of non-facts and bullsh!t, (just like the internet and especially forums and other blogs), please do not believe entirely without exercising your intellect. Any resemblance to real things in reality is purely coincidental. You are free to interpret/misinterpret the content however you like, most likely for entertainment, but in no case is the text written on this blog the absolute truth. The blog owner and Blogger are not responsible for any misunderstanding of ASCII characters as facts. *cough* As I was saying, you are free to interpret however you like. *cough*

Friday, January 1, 2010

Sure 2*8W @ 8ohm/4ohm MPS7720 Class-D Audio Amplifier

I got this amp board with a plan in mind - to replace the Yulong that's overkill for the TV rig. And this would be cool in a computer. I studied the datasheets - the 1.6-inch apart mounting holes is exactly the distance of two PCI slots, so this would mount without any modifications. The screw terminals make connecting easy - I can tap the signal from within the computer via the AC'97 connector, I can get the 12V from the computer's PSU so power supply problem is solved (and I get auto-switch-on/off function, saving power), the only problem lies with speaker-out but I'll convert one PCI bracket for that. It'd be cool. I mean, c'mon it's an amp inside a computer, turning the computer into an all-in-one device that you can just plug bookshelves speakers into, MSI tried to do that but fail in their bullsh!t marketing.

This is how it looks like when mounted in a case. Only the power wires are connected for testing if the wires facing the rear of the case will get blocked. Turns out no problem.

My casing may look small, that is because it is, it's a low-profile case that is 10cm tall and can only use low-profile expansion cards.

And low-profile casings have their big share of problems. For one, the amp extrudes the case by just a few mm. I can choose not to close the case but I did not, for this computer needs to look good and be protected good.

So onto plan B.

Plan B in testing phase

Daiso is always a good source of cheap wood boxes that irritatingly somehow do not have a top.

Banana plugs are free bundled with the Sure 2*100 TK2050 amp - if I wanted to build a $200 amp that fights Virtue Audio's offering I'd use something gold-plated at least.

Bought an 8mm drill bit just for this - for the RCA holes.

Finished product

The Neutrik RCA connectors make up for around one-forth of total cost - why didn't I choose the cheaper one (also gold-plated) at half the price for this sh!t. Now these golden connectors look too bling.

Not shown in the picture is a Panasonic M 1000uF 16V I decided to throw in for some local power reserve.

The wood and connectors are more sturdy than I imagined.

Belden 89207 used for internal signal wiring - I only had this on-hand. It's stiff enough to keep the board in place without mounting screws.

Sound-wise, it's pretty okay for the money. Compared to the Yulong (which I just found out recently that it's very good for the price) it sounds constrained, lacks space, poor decay, swallowed highs, and weak bass, but otherwise it's acceptable, at least it doesn't make you want to turn it off or make your ears hurt, and is enough for casual listening. Which is enough for my TV rig. The difference is like a good onboard sound/entry-level soundcard versus a more-than-entry-level DAC. I've heard sub-$100 amps sound worse.

It currently does not have a power supply, a power switch, and a volume control, all of which together will add significantly to the cost of the amp, hence I left them out. I did not have plans regarding the power supply since it was originally intended for use with computers, so get an extension cable and pull the power from the computer. My Seasonic's long cables helped in this aspect. Volume control might be required for safety though, as this can get quite loud and can blast ears off at Windows' default volume setting - with volume knob at max on both Yulong and this (no volume knob actually) I listen at around 1/6 with Windows' volume control , max.

Because of the lack of power supply, switch, volume control, a sturdy case with a top, other complete products may provide more bang for the money if you just need something that works. The JAM Acoustic Audio Amplifier @ $59 w/o PSU and $79 w/PSU and Scythe Kama Bay Amp @ $80-ish are good competitors, though I'm not sure which would sound better out of the three. But if you just need something quick and dirty for use with a computer and/or can use the computer PSU for power supply, I highly recommend going for this.

Just make sure you have more space at the PCI slots, mounting this in the computer is where the beauty of this thing is, or should've been.

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