Can you recommend a 9 or 12 v amp that can develop more than 1 watt?

[momo]

Hi there, here I am back at building after 5 years off!
I missed this hobby very much and I now have spare time and so here I go again!

I would like to restart by building amps.
I have already done the Ruby, Noisy Cricket.
Looking for anything hotter to power my great 10 inch 15 watt vintage speaker ....
I have read up on the Tiny Giant and it seems great, anything upgraded since this circuit was developed?
Pardon my ignorance, I have been gone 5 years, an eternity for these great circuits!
Cheers

OH and I want to mention as for IC chips I have the 386 and the TL072, I guess my options are limited, I know the Tiny Giant uses 072's....anything else?

[seadi123]

Build this preamp http://www.till.com/articles/GuitarPreamp/ and place it before this lm386 power amp http://www.hobby-hour.com/electronics/lm386-20.gif . It still will not produce more then 1W output , but you will have a decent room volume without any distortion . Or , you could buy one of these and use as a power amp http://www.ebay.com/itm/TDA7297-2-15W-Audio-Amplifier-Board-15W-15W-Dual-Channel-DIY-AC-DC-12V-Update-/371061943341?pt=US_Home_Audio_Amplifiers_Preamps&hash=item566503ec2d , for a nice 15w output

[MaxPower]

Can't help you with the 386s and TL072s, but if you can get some NJM2073s you can get 1-2 watts out of it (using the bridged configuration) depending on power supply and load. The schematic (BTL configuration) is on the DATA sheet. http://www.datasheetcatalog.com/datasheets_pdf/N/J/M/2/NJM2073.shtml

I built one and power it with 6 D batteries. I have it connected to a speaker (tower?) from an old hi-fi system. It has two 8" speakers and two 2-1/2" tweeters. It's plenty loud for my bedroom (I don't run it at max volume). I don't know how long the batteries last as I've only mucked about with it a few times. I built it for those occasions when the power goes out (which is all too often around here).

If you should decide to build one, be sure to add a coupling capacitor at the input.

[Seljer]

I built one using two LM386s in a push-pull configuration as per the bottom one here http://www.runoffgroove.com/littlegem.html and going by measurements, it does actually put out a watt and a half! Theres some slight asymmetry when it clips, as a well as a bit of crossover distortion, but it is twice as loud as a singal Ruby. And remember to isolate the output from the case if you're not wiring it directly to the speaker.

[tca]

Did you put the LM386 to deliver 1W? You can't do that with regular 9V batteries (only for a moment or two). Try to power the LM396-3 with a decent power source (filtered) that can go up to .5A.

Cheers.

[Mark Hammer]

Most of the single-chip stereo amplifiers for cheap computer speakers can be wired in bridged/BTL mode for additional power.  Essentially the two channels are used like a push-pull amplifier such that one channel pushes when the other pulls.  Common ones are the NJM 2073, or the TEA2025.  Both of these will give you a couple of watts in bridged mode.  Their respective datasheets will show you how. 

Of course, there is nothing that says you couldn't do the same with a pair of 386 chips.  See the runoffgroove Little Gem Mk II (http://www.runoffgroove.com/littlegem.html).  I'd recommend using a pair of LM386-4 chips for that.

Whatever you make, note that a higher supply voltage and lower-impedance load will generally get you more power (within limits; some chips indicate more output with a 16R load than an 8R load).  And of course, more power always requires more current capability.  You'd be very pleasantly surprised by how loud a humble 386 can get when powered by 8 AA batteries.  I have an LM380-based mini-amp, using a 6-1/2" speaker with a big fat magnet, and an 8-pack of rechargeable C-cells.  And that sucker is surprisingly loud.

[momo]

Thanks everyone!...I love this forum, so great!
I think some of you gave me stuff not posted here as I thought you would, awsome.
Hi Mark, nice to see you are still here!
I think R.G is still around?
:-)

anyhow, here are a few pics of enclosures and previous amps I have made.
What prompted me to get at it again was that with my main enclosure, the black one with the great vintage 15w 8ohm speaker,
was that I plugged my 12v supply backwards, had no protection and some smoke came out of there...
I was bummed out but then I just changed the chip and transistor on the Bassman mod Ruby amp and it worked.
I am not sure its at full power though, maybe some caps were damaged, I took the power out fast.
So this will be my main amp I want to build just to bring on anywhere I go.
The other amp that I will gut and start over, keep the circuit but change enclosure is that butterfly type amp.
It has another ruby in there or similar, not sure as well as a heartthrob tremolo.
I love it but the enclosure is made out of some kind of cardboard and wood mix and it sounds...well....cardboardish..
lol
I might try to fit it in this other "National" speaker enclosure which scores major points for looks, but I'm not sure about the speaker, will have to try it out...
Its a rainy day today, perfect!.....will have a long day creating and tinkering....love it!
I'm happy to get back at this hobby, its so great to create something, plug it in and make noise..

[rutabaga bob]

Welcome back!  I really like the last photo, with the 2 hinged speakers...I converted an old tube phonograph into a guitar amp once that opened like that - the speaker was in the lid.

[momo]

thanks bob!
I just destroyed the last one you talk about, it does have two speakers but it sounded real cheap.
Will try to upload the circuit into something else.
I remember having motorboating issues because of the two speakers and R.G had helped me with that.
It was real touchy, a few centimeters too much speaker cable and that boat would show up again.
I really wished this one would be great as it is as I love the butterfly concept with two speakers, but it did not sound good and the box was falling apart because its cheap pressed wood chips like cardboard.
On to figuring out where to put the circuit..!

[momo]

Well my head is spinning right now, I have so many enclosures, don't know which to use. Debating if I am going to put the amp circuits in the boxes for combo effect or box it in its own little box to be more versatile and use with different speaker enclosures.
I have so many funky boxes!
Most of them come from old movie projectors.
Check out the little tube preamp, I forget the name, got the circuit here and I remember how great and warm it sounded.
I even have these custom alu enclosures from a member here, sorry I forgot your name...

[momo]

So I thought I had a noisy cricket, but its a Little Rebel....2W

SO I do have a stronger battery amp...
lol

[PRR]

> a 9 or 12 v amp that can develop more than 1 watt?

*Every* car radio runs on 12 Volts and the worst of the bunch delivered 2 Watts in 8 ohms, 4 Watts in 4 ohms.

Today nearly all deliver 16+ Watts in 4 Ohms (8+W in 8 Ohms).

The Tiny Giant uses a car-sound chip with a ~~12V supply to deliver such powers.

Your speaker is rated 15 Watts 8 Ohms. That's 15W "music", full band, low overall distortion. Guitar alone may be grossly distorted, which is much more stress on the speaker. Not to mention it isn't as young as it used to be.

While you could do your figuring and come up with an odd battery voltage to get 4W-6W in 8 Ohms which might be safe, it may be simplest to just go with 12V and accept the 2 Watts in 8 Ohms that you will get. Especially with AA-power, because that is EXpensiVE enough already at the 2W level.

TDA2003 is an excellent simple car-sound amplifier for this purpose. Use the suggested schematic in the data-sheet:
http://www.st.com/web/en/resource/technical/document/datasheet/CD00000123.pdf

Put a simple preamp and whatever tone you want in front.

CanaKit has all the parts in a bundle for $13 kit.
http://www.canakit.com/10w-audio-amplifier-kit-ck003-uk003.html