Off-Grid Party Sound Systems

Step 4 Notes on the Sure Electronics TK2050 100W amps

I got 2 different TK2050 amps from Sure Electronics - their original 100W system and the "improved" 100W system.  These are both "bare board" amps.  At $40-$50 for a 2x100W amp with 85%+ efficiency, these are amazing deals under any circumstances.   I recommend the "improved" amp because its umm - improved!   ok here's the deal:

• With the original amp you must use a powered mixer (see next step) to boost the levels from the mp3 player.  If you don't, you will get at best 5% of the rated output.
• With the improved amp, you can get about 25% of rated output plugging your mp3 directly to the amp.  This isn't bad, but you still need to use a powered mixer to get full output (see next step).
• Another note about the "improved" amp: it has a small heatsink with a fan. I'm not a big fan of fans, because they are failure prone in dirty or vibratory environments. I've been using this amp inside a speaker and letting the airflow from the woofer cool the amp - this means i can chop out that fan.

The technical details:

• The original amp has "low input sensitivity".  This is a fancy way of saying that it has no volume knob, and the volume is pre-set at "low".  Kinda dumb.  If you try to power it from an mp3 player, the maximum volume on the mp3 player won't run the amp close to its designed power level.  If you are handy with a soldering iron, this volume problem is easily fixed by replacing 2 resistors.  If not, you need the powered mixer.
• The "improved" amp improves the volume problem - it has a set of switches on board that let you choose the desired volume (3 choices).  Even the highest setting won't get you to full power with an mp3 player, but at least its usable. 

If you want to hack your original amp to change its volume setting, check the photos:

Comments

[netrunner]

For the older "SURE electronics" 2x100W @4ohm KT2050, its R18 and R33 to modifie. 6,8Kohm can be added in parallel.

That is 1 resistor lower then in the picture. Can be a mistake in picture.

http://www.sure-electronics.net/download/AA-AB010_Ver1.0_EN.pdf

[saltvand]

The TK2050 thaqt I have looks i little bit different. See it here: http://img411.imageshack.us/img411/4465/img4302r.jpg IS there a way I can increase the volume on my model?

[dan]

oh, the other solution is to use a powered mixer to boost the mp3 player signal before the amp. i'm using a Rolls MX51s which is about $50.

[dan]

you have the 4-channel version. i think yours must have the pre-amp chips on the underside of that daughter-board. can you un-plug the daughter card and post a photo of the bottom side of it? (close up, use macro-mode on your camera).

[zeroemission]

forget the lower SQ on the new units, it's FINALLY possible to get more than a puny 10wpc on a bike system without having to kowtow to scambay & crap-pal! LOL i've been wanting to get hold of a sure for over a year at least!

10wpc is plenty loud for daytime cruising even with little 86dB 2 ways, but as soon as it turns night, you can't hear your own system anywhere within 50 of a nightclub door where all the "friendly gals" are hanging out. LOL

i have 2 unbuilt bare bones sonic impact modules that will collect dust as i'll be getting one of these for my next build. 70w is almost 9dB louder than 10w.

i also like the look of the sures. i'd like to put one under plexiglass with fake LED blacklighting & possibly replacing the fan with an illuminated one if there's a match.

until you start getting into building amps from scratch or going with big heavy car batteries, this is THE best amp you can get for a street party bike at the moment. i'm getting one for sure! (sorry about the pun)

[elinventor21]

So if i were to hook up an mp3 to the amp alone it wouldn't sound even if the speaker was smaller?