I just finished up my first mini amp kit - the 2.5 watter from Gitty, and am very pleased with it. Now I want to build more (of course). I'm new at this and wonder how big a speaker you can drive with 2.5 - 4 watts.
Also, how long would you think a pair of 6v lantern batteries wired in series would last in one of these? I'd like to have a long-lasting set-up for craft fair demos.
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i would think a 10 or a 12 , but the ones i have built i use 5 or 6 inch just to keep the size down . i have watched vids of guys using 1 watt mini amp circuits on 4x12 cabs . maybe try an 8 or whatever you have laying around first ?
on the subject of batterys i am the last guy you would want to listen too but here i go :
personally i would go with a smaller 12 volt sealed lead acid battery or something that is similar , they are rechargeable . they also sell those at radio shack , you may even get that cheeper at wall mart if they have something for a lawnmower . you can even use a car battery charger for those , on the lower "trickle charge" or 2 amp settings . even a 1 watt motor cycle battery charger (those are really cheap) will work . but with a really big batt i use a transformer thingy . like something that goes in the cig lighter in a car with settings for 3 , 5 , 7 , 9 , 12 volts ...
in a pinch you could use a car battery or deep cell , with a transformer , or cell phone charger to lower the amperage ... if you plug that straight in , you would more than likely see some blue smoke . i have one amp that uses c cell sized ni-cads out of a cordless drill batt pack . i really hate the idea of buying and disposing of batteries .
they also sell remote control car batteries / chargers with smart technology , and potable dvd player batteries , nihm is better than nicad , it has no memory , then there is lithium ion .
i was looking over here the other day , these guys are really into that sort of thing ,
http://taperssection.com/index.php?PHPSESSID=b74f2f50eb241630c60a9a...
i usually go with deep cells and transformers cause i used to run a boat with all sorts of crap .
https://www.youtube.com/watch?v=i9hEr38yboY
the sla 12 volters i got have lasted a LONG time , running a car amp on a kicker box with a car stereo . i really havnt had the chance to fully wear down any of my mini amps yet though , but ... not sure how long you are going for and mine are lower watts . with batteries for me bigger is always better , also having an output to power pedals is nice on an amp too . i got a batt tester from the dollar store that i am going to cut in on the drill batt amp , the kicker box has a cheepo digital tester from auto zone to keep an eye on the volts . sure i could use a meter but , its nice . for the ni cads on the drill amp i use an old battery charger for aa - 9 volts . it takes a while but , its safe .
good luck , please share your findings , i am interested in this subject .
It'll drive whatever you hook it up to. I've hooked up a Stella amp (1-2 watts) to a 12 inch speaker with no problems (if I was more organized I could find the video of it and post it, but I was looking for it the other day and couldn't find it.) With larger speakers you might run into issues with muffled highs.
Anyway, you can't hurt the speaker to try, and as long as the amp can handle the ohm rating of the speaker then you can't hurt the amp.
Edit: Here's a smokey amp (LM386 based, 1/4 watt) hooked up to an 8 inch speaker:
https://www.youtube.com/watch?v=O0zAjyPVCuA