Hi Guys, time to ring in the new year with a new contest!
Post your battery powered amps. Please include pictures, description of circuit or schematic, and (if possible) sound clips.
Since battery powered amps tend to be a stepping stone into AC powered amps, I'll be giving out kits for AC powered amps for the winners.
First Place: Stereo LM1875 Kit from, Mono LM3886 board (with integrated PSU) and 25 chip points.
Two Runners Up: Mono LM3886 board (with integrated PSU) and 10 chip points.
Thanks go to Brian at chipamp.com (http://chipamp.com) for making this contest possible, all boards and kits are from his store.
**edit**
The contest only goes until January 31st!
Free shipping for the prizes!
Wow, if no one posts in here I'm going to put up my most recent battery amp and call myself the winner :P
I'll post some pictures of the Little Gem Mk II I recently built. It's not quite finished, but is currently functional as is.
A little more time to put something together would be nice ?
How about extending it until Feb 1st ?
Quote from: Brymus on January 15, 2010, 03:59:12 PM
A little more time to put something together would be nice ?
How about extending it until Feb 1st ?
Fair enough. Consider it done :tu:
Quote from: rowdy_riemer on January 15, 2010, 12:02:23 PM
I'll post some pictures of the Little Gem Mk II I recently built. It's not quite finished, but is currently functional as is.
That's fine. Just post what you have. I really want to give out these kits :tu:
Well, how about this, I'll take some pics today and post them along with the not-so-well recorded clip I've got at the moment. Then, if I get done with any changes before the 1 Feb deadline, I'll post those. I've got some much abused LM386's on the board right now that I recorded with. They sound not so well when overdriven. The ones that were originally on the board were fried when I accidentally wired up a battery back to it with the wrong polarity. :( I'm gonna try to pick up some more LM386's during my lunch break along with a 2 D cell battery holder to add to my 4 D cell holder. If I can do that, I can probably get some decent overdriven sounds for to add to my previously recorded sound clip.
Hi, I've built two battery powered amps actually, one for guitar and another one for bass guitar. But I'll only mention the one for guitar because it turned out to be the most successful one so far. (Maybe I can post it later if anyone wants to know).
It's a Little Gem amp mounted in a open back cabinet with two fullrange speakers. For you how aren't familiar with the Little Gem amp it's a really simple (but sounds quite good anyway) cicuit based on the LM386 1/2 W audioamplifier chip. The Schematic can be found at http://runoffgroove.com/littlegem.html I use a 9 v battery to power the amp, or an DC adapter. It can also be run at 12 V DC, a little more output is available then.
I use the schematic (and perfboard layout actually) found at RunOffGroove and didn't made any changes, except that I added a headphone socket (how to wired this is only found on that site I think), a DC jacket, a socket for external speaker and LED power indicator.
The speakers are some cheap fullrange speakers I bought at my local hardware store. Haven't found much data about them. All I know is the power rating and the impedance (8 ohm). I wired them in series then, to get the total impedance higher.
The cabinet is made of 8 mm plywood and covered with fabric. The dimension of the cabinet is approx. 270 X 200 X 180 mm. The plate for the controls and jackets is a piece of galvanized sheet metal.
The sound of this simple amp is pretty amazing. Well there are a lot of downsides also, of course. A EQ would probably be a good idea and maybe a buffer before the amp. But it still is possible to get some really nice tunes out of it. Really loud too for only ½ W amp. And some how it sounds like a MUCH bigger amp.
I recorded some sound clips using only the microphone on my iBook and no external speaker, only the two in the cabinet, which you can see in the pics I've attached. The guitar I played was a "modified" HSS strat-copy manufacture by J&D Brothers. No pedals or anything before the amp was used. Gain was to 3 o'clock then recorder using the humbucker pickup (bridge) and no or a little gain then playing with the singlecoil pickup (neck I think). Master was set at max or almost max.
Can't think of more to tell about this little project now, so feel free to ask if I forgotten something or so. And I really hope my langue is not being judge in this contest...
And by the way, if you're using a single coil pickup, put the gain 12 o'clock or so and direct your guitar in the right position, you can pickup the local FM-station with the amp. Just enough loud to be able to hear it with the master volume at max. :)
Pics
Overview (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01309.JPG?attredirects=0)
Back (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01335.JPG?attredirects=0)
Top (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01351.JPG?attredirects=0)
Inside (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01358.JPG?attredirects=0)
Inside 2 (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01363.JPG?attredirects=0)
Speakers (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01364.JPG?attredirects=0)
Front (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/DSC01391.JPG?attredirects=0)
Soundclips
Humbucker 1 (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/Humbucker1.mp3?attredirects=0&d=1)
Humbucker 2 (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/Humbucker3.mp3?attredirects=0&d=1)
Humbucker 3 (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/Humbucker4.mp3?attredirects=0&d=1)
Singlecoil (http://sites.google.com/site/pyromaniac0000/home/little-gem-amp/Singlecoil1.mp3?attredirects=0&d=1)
Dude, filefactory really seems to suck. You can host these for free with google sites. http://sites.google.com
Yes, it totally does! Therefore I put all the pics and soundclips at google instead. Thanks for the tip, and hope it will work better for you now.
No prob. That works much better now. BTW, you're amp looks pretty cool. :tu:
Ok, here's a discription of the Little Gem MkII I built (Thanks ROG for a great circuit). For those unfamiliar with the Little Gem MkII, it is a dual LM386 version of the Little Gem http://runoffgroove.com/littlegem.html (http://runoffgroove.com/littlegem.html). I used Pablo De Luca's PCB layout. Everything is housed in an old school intercom speaker box. A friend of mine was working a construction job at a school were a few of these were being thrown out, so he gave me a couple. The speaker is an 8 inch speaker that I removed from my Peavy Valveking Royal 8 (which now has a Jensen Mod 8 ). I have no idea who manufactures the speaker. Its probably some no name Chinese made speaker. If I had another spare Mod 8, I would probably use it for this project too.
This amp is about as simple as an amp can be. There are no controls other than what you have on your guitar. There is a single jack that also functions as the on-off switch. I'm using 6 D-cell batteries to supply 9 V. This amp seems to behave better when using D cells rather than a single 9V battery. For now, there is no external power jack.
Here are some links to some pics and sound samples. Please forgive the sloppy playing. :-\
Pics:
http://www.riemer.us/littlegemmkii/LittleGemMkII.jpg (http://www.riemer.us/littlegemmkii/LittleGemMkII.jpg)
Front: http://www.riemer.us/littlegemmkii/LittleGemMkII_front.jpg (http://www.riemer.us/littlegemmkii/LittleGemMkII_front.jpg)
Top: http://www.riemer.us/littlegemmkii/LittleGemMkII_top.jpg (http://www.riemer.us/littlegemmkii/LittleGemMkII_top.jpg)
Inside: http://www.riemer.us/littlegemmkii/LittleGemMkII_inside.jpg (http://www.riemer.us/littlegemmkii/LittleGemMkII_inside.jpg)
Circuit Board: http://www.riemer.us/littlegemmkii/LittleGemMkII_circuit_board.jpg (http://www.riemer.us/littlegemmkii/LittleGemMkII_circuit_board.jpg)
Sound Clips:
For all of these, I used my Ibanez RG5EX1 with a cheap ass Behringer Tube Ultragain Mic100(which just as well be all solidstate) mic preamp and a Nady SPC-25 condensor mic. None of this is top of the line equipment, but is fine for my purposes and fits my budget. I used Audacity for recording. I think my greatest limitation here is my lack of recording experience rather than the limitations of the equipment.
Bridge pickup in single coil mode: http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-BridgeSCMode.mp3 (http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-BridgeSCMode.mp3)
Bridge pickup in humbucker mode: http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-BridgeHBMode.mp3 (http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-BridgeHBMode.mp3)
Bridge pickup - Overdriven http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-OverDriven-BridgeHBMode.mp3 (http://www.riemer.us/littlegemmkii/LGMK2-RG5EX1-OverDriven-BridgeHBMode.mp3)
For whatever reason, I have a hard time overdriving this amp with just the output from the guitar. I certainly do not have this problem with the Ruby. I've read somewhere where someone modified the Little Gem MkII circuit with a dual pot for gain control. Such a mod might make this amp better. For the last sound clip, I used a pedal for some clean boost to overdrive the amp. I liked the sound of this amp better than with any Ruby/Speaker setup I've personally done so far, though I've heard some really good Ruby setups on youtube. Maybe turning the gain pot down on a Ruby and using a booster pedal or preamp would have similar results.
Quote from: rowdy_riemer on January 20, 2010, 05:05:18 PM
No prob. That works much better now. BTW, you're amp looks pretty cool. :tu:
Thanks, your amp looks good, really vintage using a such intercom box, not a bad idea. Just wonder if the back i open as in the picture, or if put something to cover the back then you play?
I leave the back open, though I should probably see how it sounds when its closed.
Excellent entries guys, keep 'em coming!
I have been extremely sick this last couple of weeks,go back to DR in a couple of days.
So I may not make this contest :(
I havent been able to do much and putting an amp together is way down on my list at the moment.
The one I saw above looks really nice...
If I start to feel better before the deadline I will try to throw one together.
I already had a plan in mind for one :duh
If not then oh well,maybe next contest I can enter something.
Keep up the good work guys,and I hope to see some more entries from other people too.
:tu:
BTW I didnt want to sign up for yet another site to view those other pics of the second entry would you mind hosting them somewhere else so I can view them a little easier ?
QuoteBTW I didnt want to sign up for yet another site to view those other pics of the second entry would you mind hosting them somewhere else so I can view them a little easier ?
I think I'm the second entry. These are hosted on my site and should require no one to sign up for anything. They should be easily accessible. If you still have problems viewing them, I'll post them from my local machine.
QuoteI have been extremely sick this last couple of weeks,go back to DR in a couple of days.
BTW, hope you get to feeling better.
QuoteBTW, hope you get to feeling better.
Hey, me too.
Wish you the best. :tu:
Thanks guys !!!!
I am hoping to feel better soon as well ,its hard to do much of anything feeling the way I do.
Thanks for the kind wishes,very appreciated.
Just one more day folks! Post up what you have even if it's not finished :tu:
The contest is closed!
I will announce the winners in the next couple days.
Winners:
1st Place: pyromaniac_ (http://www.ssguitar.com/index.php?topic=1456.msg9225#msg9225)
2nd Place rowdy_riemer (http://www.ssguitar.com/index.php?topic=1456.msg9232#msg9232)
Great job guys!
WHoohooooo!!!!. Congrats, pyro. :tu:
Thanks, and congratulations to you too!
Now we deserve to see the winner's works.