Kemo M033N 18 Watt Universal Mono Amplifier Module

Brand:|Model: M033N
The Kemo M033N is a robust, versatile solution for projects that call for an audio amplifier.
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Part # 320-553
  • Self-contained amp module
  • Sealed construction for harsh environments
  • Built-in speaker protection

Product Details

Kemo M033N 18 Watt Universal Mono Amplifier Module

The Kemo M033N is a simple, resilient solution for adding an amplifier to any electronic project. The thermoplastic casing is resistant to humidity and requires no additional heat sinks. Protection against overload and overheating is included. All connections are through the attached leads.

Specifications: • Operating voltage: 8 - 20 VDC • Current consumption <800 mA • Input sensitivity: < 80 mV • Compatible speakers: 4 - 16 ohm • Output: maximum 18W into 4 ohms with 20V power supply • Frequency response: 40 - 20,000 Hz • Dimensions: 2.76" x 1.42" x 0.91".

Kemo M033N 18 Watt Universal Mono Amplifier Module
  • BrandKemo Electronic
  • ModelM033N
  • Part Number320-553
  • UPC4024028030333
  • Product CategoryAudio Amplifier Boards & Modules
  • Unit of MeasureEA
  • Product Rating
    (6 Reviews)
  • Weight0.3 lbs.
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Kemo M033N 18 Watt Universal Mono Amplifier Module
Kemo M033N 18 Watt Universal Mono Amplifier Module is rated 4.1667 out of 5 by 6.
Rated 5 out of 5 by from A puzzle on a puzzle.A push to solve noise problem. First-1. Noise with volume off-(shorted input) Second- Noise coming thru the input. Third- other. I really thought this unit was hopeless--But I lucked out. #2- this turned out to be not that much of a problem. Total sheilding of the input wires was not required. I used 2 330 Pf caps to ground. no RF got thru. Second: A devil !! Certain power supplies would not work. 120Hz noise coming in. These were non switchers: I attributed the racket to no suppression of their diode noise. One could build a whole new analog supply using soft recovery diodes & 100nf caps spread around. But not today! So on to switchers, which varied. High pitched noise was expected, & I got it! Used a 1nF cap across (+dc) & (- dc). Meh! not good enuff. But a third supply turned out to be better then the rest! On to sydrome #3- Random RF. I knew this would be a global sheilding event, and set out to box the unit up. Ugh. Changes the quick/dirty nature of the whole thing! So next day, I spies a small piece of aluminum, 2.5 X 4", and I plunked it on top of my units, two of which were just that size. Amazing! No racket! nothing! dead Quiet! what a pleasure! I did not even ground the plate, even tho that makes sense. Kemo came thru-but what an ordeal!
Date published: 2014-01-25
Rated 4 out of 5 by from Minor issues, but not badI'm using this amp to power a single 20w speaker in a little portable iPod audio system I made for fun. Power supply is a 12v 1a ac/dc adapter I got for $10.It has sufficient power (with iPhone input) to blow the speaker and sounds acceptable for a small project.As mentioned in other reviews, this unit is very vulnerable to interference. I spent a good amount of time tinkering, and here are my solutions:Input grounding: ground the negative terminal of the input jack (and your potentiometer) direct to DC negative terminal, not through the amp as the instructions say.Radio shielding: I was also picking up some top-40 station in the background, so I wound some ferrous project wire around the unit about a dozen times and connected to ground terminal. Reduced interference by about 90%. An aluminum project box would probably solve the remainder, but my project wasn't exactly audiophile quality anyways.Overall, this is a good choice if your space requirements call for it. If you have more space to work with, then go with a Sure HiFi amplifier module. I've had 0 problems with those.Hope this helps.
Date published: 2013-11-02
Rated 1 out of 5 by from TERRIBLEThey are terrible. I powered them with the nominal 20v and they still didn't make anywhere near 18 watts. I verified this with two separate units, and they were both really weak. I also tested two switching power supplies with same result.Additionally, they seem to have NO RF shielding whatsoever. They easily picked up FM radio when powered on. Not just faintly, you could tell what song/words were being played on the FM channel.Lastly, aside from the RF issues, the noise floor on these was terrible. Audible hiss when playing any sort of music.I cannot believe that these are being sold by Parts Express at all. They are going back for a refund ASAP.
Date published: 2013-05-16
Rated 5 out of 5 by from Convenient, economical, and sounds good, too!I implemented this nifty little amplifier in a boombox-type 2.1 system to power the woofer. The left/right signal, split off before being sent to a separate stereo amp, is combined via a pair of 1k resistors to feed this amp. (I'm not too concerned about the resulting bit of crosstalk in the mids/tweets with this type of system.) Input level is trimmed via a 10k audio pot as shown in the included instructions. Connections are simple and reliable using wire nuts or solder joints and shrink wrap. Sturdy mounting holes make it easy to screw down.Sound is good, producing more than enough power for this not very demanding application. Powering the amp is a 12V 1A regulated AC/DC adaptor.
Date published: 2013-02-20
Rated 5 out of 5 by from YES!!Its a "roughly" 18 Watt amp. Self contained and dose not require a heat-sink. You would be crazy not to buy it. I haven't actually test the sound quality yet, but when I do ill let ya know.
Date published: 2013-02-16
Rated 5 out of 5 by from Great Little Amplifier, Getting More!Not too Long ago, I thought up a design for a portable audio monitor, or Speaker. This unit looked good, so I went for one, And I am extremely happy with this purchase, worked Really well right out of the Box. And.....Its NOT made in china! Germany, of all the places....And the quality is very good. I plan to get several more.The unit came with instructions, which were good, And the included I.instructions, provide a simple block diagram, to show how this unit can be used with a 10K ohm volume potentiometer, for controlling the volume. The curcuit included worked, And the whole thing worked Really well, And most of all, has a great sound quality to top it all off, I just wish the wires were longer, but wasnt a problem. I recomend a DC power supply of 15-20V, for best output, but does work flawlessly on 9V. I used a tang band 4" neo 4 ohm speaker with this unit, perfect. Just perfect.
Date published: 2012-12-16
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Product Q&A

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Kemo M033N 18 Watt Universal Mono Amplifier Module

How would a 9v battery work with this amp?  What do you estimate would be the wattage out from the amp to the speaker?

Asked by: bpmoose
A 9 volt battery will technically power this amplifier although most 9 volt batteries have a fairly low mAh rating, which means they will not last very long.
Answered by: MattP
Date published: 2013-12-26

What volume knob and power supply to use with this amp?

NOTE: Uploaded image is chart of the SMALLER version of this amp.1) What volume knob from the PE catalogue should i order?-> the speaker driver will be 8 ohm.-> the diagram for a possible PE volume knob does not show the same connections as the diagram from Kemo?= how sould the L-pad volume knob be connected or can it simply not be used at all?PE l-pad volume knob I'm looking to install this amp + power supply inside a very small cabinet. So the power supply should be as small as possible. preferably no larger than 5x5x8 cm. But smaller would be even better. Any suggestions?Thanks.
Asked by: Bjorn
I've uploaded the wiring diagram for this amplifier. You will want to use a 10k Audio Tapering Potentiometer (PE 023-610) hooked as shown in the diagram. I believe you are confusing L-Pads and Audio Potentiometers. They are similar devices but used for different applications (See Note 1 Below for more info).If you are looking for a small form internal power supply I suggest a Li-Po or Li-Ion battery packs either 11.1 or 14.8. I also suggest some kind of smart charging system for them. Overcharge and imbalance charging is not a desirable outcome for your device and personal safety. Be warned that this approach is not economically friendly but has high energy density for a small package. (Design is mostly weighing out trade-offs)Too keep with the small form factor idea, you could use an external supply (ie Wall Wart or Brick). Then you wouldn't have to house any electronics other than a jack to plug into. I have listed some products that fall in line this approach. (My suggest power supply cannot be listed below, however the PE# is 129-145)Best of luck on your project.NOTE 1:L-Pads and Audio PotentiometersL-PadThe L-Pad is used to connect to a speaker, normally used in passive crossover design (Commonly to attenuate a Tweeter output to match that of the woofer). These hand high level audio signal, thus the high power ratings. Also are selected based on speaker nominal impedance (4 or 8 ohm). Some designers used fixed L-Pads in crossovers (simply two resistors) as to the variable made reference to.An audio potentiometer:Audio Potentiometers come in two flavours; Linear and Logarithmic (otherwise know as Audio Taper). The names refer to how the resistance changes when you turn the knob. Linear Pots increase in resistance in a direct relationship to turning. Audio Taper Pots try to mimic how we naturally hear attenuation of volume. (Audio taper are generally more desirable for volume control).These devices work on line level signals (so low power). These are selected based on the input impedance of your device.
Answered by: JDoyner
Date published: 2013-04-29

Will this amp work with rotary encoder & blue tooth?

rotary encoder, product id: AA-AA11117blue tooth, product id: BT-1AI am interested in using this amp with both AA-AA11117 (as external volume control knob) and the BT-1A to make it work with my iphone via bluetooth.In the Q&A i cant find any answers to this.1) will the volume control knob work with the Kemo M033N 18 Watt Universal Mono Amplifier Module2) will the bluetooth device BT-1A work with the Kemo M033N 18 Watt Universal Mono Amplifier Module3) how should i power the bluetooth and the amp.- seperately?- what power supply?Thanks in advance,Bjorn.
Asked by: Bjorn
This will work with the bluetooth adapter, unfortunately it will not work with the encoder.
Answered by: MattP
Date published: 2013-04-24

How to get mono sound from a stereo input.

I have one of these that I got last year but have not been able to wire it correctly. I want to get an iPod stereo signal and reproduce sound in one bookshelf speaker. If I take a 3.5mm plug and feed the amp the positive and negative signals from the iPod it sounds really strange. I know I'm doing something wrong. Any help would be greatly appreciated.
Asked by: boofarino
If you only see two wires out of your iPod stereo connection, you are missing the grounding wire(s). You are connecting Right Channel to the positive input of the amp and Left Channel to ground input. There are two possibilities:1. I suggest trying to separate the wires further. They are most likely surrounded by the ground wire (3.5mm TRS have really thin wires). Once you see all the wires you can then use one channel to hook up to the amp. For example the center part of the black wire to positive input and the surrounding part to the negative input.2. Then again you might have missed the green wire or striped it off when taking off the outer connector. If this is the case, just tie either red or black (not both) to the positive input and green to the negative input.If you would like to mix Left and Right Audio into your amps input you will need an op amp summing circuit. However(depending on the input impedance of the amp) I have built simple resistive summers. Put two 470 ohm resistors on the red and black wires of iPod output cable. Tie the ends together and place a 20k ohm resistor between that point and the green wire. The Positive input to the amp would be where all the resistors are tied and Negative would still be the green wire.I hope this helps and best of luck
Answered by: JDoyner
Date published: 2013-08-07

Power supply for several of these

I would like to build a portable four channel amplifier using these. What kind of power supply would be able to handle powering anywhere from 1-4 of these. If each one is routed through an SPST so that any can be on or off at a time, is there a power supply that would be able to handle that without needing extra components to rectify the power based on need?
Asked by: albrittbrat
These small amplifiers do not draw a lot of current, so any 12-20v supply that has 4-5 amp output should power these without issue.
Answered by: MattP
Date published: 2012-10-30

Power Supply

What would one use as a power supply for this amp?
Asked by: andyvp
This amp is rated to work with anything that is 8-20VDC with a minimum current draw of 800 mA. We offer a wide varaiety of power supplies that will work well. I have one listed below that is a good match.
Answered by: MattP
Date published: 2013-07-20
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