diyAudio - 100watts mono D-amp for $10 from PE

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100watts mono D-amp for $10 from PE

I found this on another forum and out of curiosity (and the 'it might come in useful someday' syndrome hit me again) so I bought two.

It's rated at 100watts rms into 1 ohm with high level inputs, DC-offset detection for turn on and fixed 150hz/2nd order fixed LPF.

Kicker 100W Car Audio Stereo Input Sub Amp with Housing | Parts-Express.com

I'm thinking of using one in a dual 6.5" TB powered sub and another for experimentation/extra.

I just opened one to see what's inside and it has six IRFZ44R's. four are used in a full bridge config, filterless class D topology. I'm guessing the other two appears to be the main power switch. I haven't powered up mine yet.

PCB part number appears to be PAM620-02. Board is conformal coated and has a manufacture date stamp of 2004.11.22

I can see 5 IC's inside. one 555, one dual comparator, two dual op amps one quad op amp and lots of discrete components.

There appears to be thermal protection and short circuit protection as it has a thermistor to the heatsink and H bridge outputs have 15mohm shunts.

main supply reservoir caps are 2x 16V 6800uF.

I'll take internal pics and some measurements like switching freq, idle current etc this weekend once I get access to my toys.

Yeah, I mulled over the thought of buying a few and then decided against it. Couldn't think of any useful application for them.

They remind me of the Bose Class-D amp modules found in some 90's GM vehicles.

well, I thought the parts alone would be worth at least $10 so if the amp is unusable, I can salvage the parts and case for another project ;)

I won't know for sure yet until I do some testing.

I did some measurements and idle current is 200mA.

oscillating frequency is... wait for it.......0Hz. :D it's class AB! lol I think someone has to change the description on the PE website.

it sounds ok, it's late so I couldn't turn it up but I think it can be useful for a boombox/pc speaker. pictures to follow....

Quote:

Originally Posted by djQUAN (Post 2464994)

oscillating frequency is... wait for it.......0Hz. :D it's class AB!

That's hilarious. Did you contact PE to let them know?

Wonder how it would sound modified to run full-range; seeing that it isn't limited by a switching frequency.

Huh,Must use the 'raw' 12V as it's rails,cause I see no SMPS?

Quote:

Originally Posted by DigitalJunkie (Post 2465436)

Huh,Must use the 'raw' 12V as it's rails,cause I see no SMPS?

Yeah, that's why it's designed to run a 1-Ohm load; to get a reasonable amount of power out of 12V.

Haven't informed them yet. I don't have an account there. I just asked a friend to buy this through PE in Amazon.com. It's a pure N channel amp so I guess it could go rail to rail. Good for power output. Not really sure about full range as I'm not exactly sure how the FET's are driven.

here's a page I made for it:
$10 Sub amp

It does not look like class D, but it has too many MOSFET for being plain full bridge class AB.