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Easy ss battery power amp?

Started by SirSix, June 18, 2012, 06:06:12 AM

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SirSix

Hey everyone, I've been search the web for some ideas and ended up reading through a few threads here and it seems like people have been in general very helpful so I figured I'd ask a few questions if that's okay. :)

I'm a beginner amp builder. I normally just build Cigar box guitars and pickups but recently I came across a brand new Ragin Cajun 10" speaker. I'd like to use it to build a combo with a simple (possibly battery powered?) amp with a tone, vol, gain, overdrive switch where the cabinet can double as a seat to play on if that makes sense.

I've seen the "Noisy Cricket" and it seems pretty simple. Seems like even though the battery doesn't last long it would still work in a pinch (with the wallwart for extended play) and even though it's not loud it would be loud enough for my uses. However I can't seem to find a parts list of exactly what I would need.

My question(s) is(are) would anyone here recommend the noisy cricket and if so would anyone happen to have a list of exactly the parts I would need to build it? Would anyone recommend a different easy project? The speaker is 10" 75w 8ohm. I have no aversion to dropping the battery powered aspect in lieu of a decent, easy-ish, amp project. I've researched the best dimensions for the speaker and have plenty of Cedar I can work with for the cabinet. I'm also pretty competent with electronics even if I'm completely new at building amps so soldering etc is not an issue for me.

Thanks ahead of time for any input or info! :)


J M Fahey

Agree and add: start with the noisy cricket.
Good practice and is fun.
Just not too loud.
Enough to annoy family, not much outdoors.
To play outside (or in a Subway station, a downtown street, an open air cafe, a beach, etc) you need a car-amp type chip (TDA2005 or newer versions) which can supply clean 16W RMS (which is a lot if you play alone) fed from a 12V alarm type gel cell battery, which is about as much weight as you will want to carry.
Or a rechargeable NiMh cell pack. 8 or 10 AA ones . Much lighter but less playing time.

SirSix

#3
Thanks guys!

Sweet thanks Tonyharker. I've seen people mention that here and there. I was originally planning on going with something like that but figured I would see if maybe someone knew of something maybe one (small) step up and a little more functional. Though I guess I don't know if the Noisy Cricket would be sufficient or not, it may just be!

J M Fahey. Do you have any recommendations for an amp like that to build?

Basically I'd like to just have and easily portable combo jam station, something I can throw in the back seat, pull out, plug in somewhere or slap a battery in, sit on and just jam. I'm pretty handy building things and have plans drawn out for the cabinet and I'm fairly proficient with soldering and etching and such. I wouldn't mind a more powerful/slightly more challenging amp to build if you guys think it would better suit what I'm looking for.

Also where would be the best place to buy all the parts? My local Radioshack is ... less then stellar. Great if I wanted a cellphone cover though ... Haha :)

P.S. My thoughts with the battery were that if I were to get a hankering to play I could just set down for a few songs and play via battery and if people seemed interested or if just sitting at home maybe switch over to powered for extended play.

J M Fahey

Start by building the Noisy Cricket which is well documented on the Web, I guess the drawing for a thermal transfer (iron on) PCB is published in General Guitar Gadgets or some similar site.
Build it even if too small, for a good hands-on practice (which , by the way, is FUN and usable).
When you want higher power, search for any 12V car type amp kit, don't suggest a specific one because it depends on where you live, but search around.
Even Radio Shack might have something !!  ;)
Youcan plug your guitar straight into it for clean sound, use a distortion pedal as a preamp or builf one of thgose FET tube am simulators (Dr Tweed for bluesier sounds, Dr Boogie for Heavy Metal), all of them work from 9V, easily gotten from your 12V battery.
Go for efficient guitar speakers, you don't have power to spare.
Worst are car type woofers, muddy and unefficient; best are Jensen MOD 6-15 or 8-20, relatively inexpensive, and the real thing.
Try to get them in 4 ohms.

el nino

Quote from: J M Fahey on June 20, 2012, 02:54:29 PM
Start by building the Noisy Cricket which is well documented on the Web, I guess the drawing for a thermal transfer (iron on) PCB is published in General Guitar Gadgets or some similar site.
Build it even if too small, for a good hands-on practice (which , by the way, is FUN and usable).
When you want higher power, search for any 12V car type amp kit, don't suggest a specific one because it depends on where you live, but search around.
Even Radio Shack might have something !!  ;)
Youcan plug your guitar straight into it for clean sound, use a distortion pedal as a preamp or builf one of thgose FET tube am simulators (Dr Tweed for bluesier sounds, Dr Boogie for Heavy Metal), all of them work from 9V, easily gotten from your 12V battery.
Go for efficient guitar speakers, you don't have power to spare.
Worst are car type woofers, muddy and unefficient; best are Jensen MOD 6-15 or 8-20, relatively inexpensive, and the real thing.
Try to get them in 4 ohms.
Hi Fahey... I'm planning to build Rog Supreaux or eighteen and connect it straight to Tda7056A some 3watt poweramp with 6"cheap full range speaker & power it with single 9 to 18v,
question is:
do i need to mod that supreax to Match with the power amp? Sory for the stupid question... thank's in advance
my guitar want's to kill your father

J M Fahey

No mod needed , it will work fine.
Why the TDA7056?
It needs 12V and 16 ohm speakers.
I'd rather use an old classic TDA2003 which can easily drive anything from 2 to 8 ohms with the same 12V or any other similar modern chip amp.
And you'll find tons of kits with it ... but it won't be happy with 9V.
Check the datasheets: car type ones need 12V up ; those intended for portable radios and such are happy with 9V, some even with 6V (LM386) but are at the edge of the precipice with 12V.
So decide beforehand whether you want a pocket type amp (9V battery) or a larger "street" type one (12V lead acid battery or NiMh pack)

el nino

thank's Fahey, i just want to build a small amp kind a micro crush but with better sound, could it? hehe..
i think i'll go with tda2003, and powering it with 12v adaptor & two 9v battery when i'm travelling...
my 6 inch fullrange speaker is rated max 80Watt no chance to blow,but how long two 9v  battery will last for it?...
Thank you again Fahey
my guitar want's to kill your father

its_cabs

Hey guys, its cabs, new to this whole thing, with some basic questions...
Uh... well, yesterday we checked the circuits on a board I pulled from a 5 watt Washburn LA Lyon practice amp, which was fully functional in the pawn shop where I found it. It was equipped with a 6 inch, 8 ohm, 5 watt speaker. I put the rig in a cigar box with 2x 4 inch, 4 ohm, 5 watt Nippon American speakers, which I bought at the local music supply store for dj's and assorted hoods, so expect these are guitar speakers, maybe. Any way to know?... Anyway, after running power supply to the 1st speaker, I ran wire from the 1st speaker to the 2nd. All the circuits look good, but no signal comes out the guitar input jack. All wired to a 9v battery supply, with optional 9v dc plug. Any ideas?
When we're done with that, I am interested in building some loud, powerful street gig and coffee house proof portable twin (or stereo) amps for blues and fingerpicking style solo guitar, again, with assorted cigar boxes, which are pretty easy to get here in Costa Rica. The neighborhood radio zjack, on the other hand, has very limited supplies. Free trade agreements and all, you understand. But there are well stocked electronics shops, no problem. Have any of y'all tried the NJM 2073 stereo amp, rather than the ever popular 386 or 820 amps? Thanks a bunch for the help. -cabs

Roly

Quote from: el nino
how long two 9v  battery will last for it?

There are quite a few variables with battery life, but the two main things are how hard you push it for how long, and the overall efficiency of your rig - the main factor being the speakers.  The more efficient your speakers are in converting electrical power into sound the less power you need for a given effect/situation, and the longer your batteries will last.  generally speaking smaller and car speakers are not noted for their efficiency (dB/watt).  As a guide, 80 to 110dB per watt is the range pathetic to brilliant.

I saw a buskers' rig the other day that might give you an idea or two.  It consisted of a small hand truck (aka "L" or "P" trolly) with a small sealed car battery at the bottom, a homebrew speaker box with two 10-inch or 12-inch speakers (at right-angles for dispersion) in the middle, a car radio as the power amp, all topped by a small mixer, with a looper/sampler, and CD player for backing track.  I suspect it also had a built-in battery charger.
If you say theory and practice don't agree you haven't applied enough theory.

el nino

thank's for this valuable info..
I'll start building my supreaux mini amp next week...
I'll post here when it's done...
my guitar want's to kill your father

J M Fahey

Just as a guide as what can be made, I sell tons of my "Callejero" ("Street Guy") battery powered amplifiers.
I use Lead Gel Cell Alarm Type batteries: cheap, reliable, somewhat heavy but still transportable:
a few examples:
A biamped 30W one: TDA2005 (woofer) + TDA 2003 (tweeter) .
Loud and CLEAN!!


A 60W Bass amp , with a 12" speaker, conventional bipolar power amp, and 12 to +/-35V switching converter:

A 100W bass amp, similar to the 60W above, but with 2 batteries and a much heavier speaker.
Quite heavy but enables this double bass to be heard open air, such as beaches, public squares, etc.

el nino

hey there,i got some problem, i can't find transistor J201, all i can found is
MPF102
2N5458
2N5952
2N5485
2N5484
bs170
2sk30A
wich one should i choose for replacing the J201,for building supreaux,eighteen or other ROG preamp?
Regards...
my guitar want's to kill your father

polo16mi

#13
I used MPF102 with pretty good success, in ROG circuits. Dont liked how they circuits works, but MPF102 do its job.

el nino

thank you polo16... I'll try MPF102
but how about 2N5458 or2N5484, are they will sound similar too? Sory for the dumb questions
cheers...
my guitar want's to kill your father