IC for practice amp with more wattage than the LM386?

Started by micro, October 06, 2007, 12:17:05 AM

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micro

Has anyone ever tried, or know of a guitar amp project that uses an IC with more power than the 386, like, the LM384 for example?

soulsonic

There's several projects that use the LM380 - which is a 2 watt chip. Look at Mark Hammer's pages, I saw that he's done one.
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ambulancevoice

Open Your Mouth, Heres Your Money

Ivana

TDA2003 or its derivatives/analogies with Rangemaster in front. Highly recommended in opposite to 386's...

Steben

Quote from: Ivana on October 06, 2007, 03:52:36 AM
TDA2003 or its derivatives/analogies with Rangemaster in front. Highly recommended in opposite to 386's...

Are you insinuating nice overdrive with TDA2003?
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Minion

If you use a LM3886 and throw a good overdrive curcuit in front of it and a good speaker you will have a kick arse 50w guitar amp, Mine rocks....
Go to bed with itchy Bum , wake up with stinky finger !!

Mark Hammer

1) The general rule of thumb is that one needs roughly 10x the wattage to provide double the loudness/volume, given use of the same speaker and input signal.

2) If battery operation is desired, more current is required for more wattage.  Keep in mind that current consumption is a function of speaker impedance, and also what is called "quiescent current", or the amount of current the amp is going to require just to sit there idling.  Clearly you want louder, but louder for longer periods is also the goal too, so keep quiescent current in mind.

3) If significant increments in wattage are needed to achieve noticeable increments in volume, using the same speaker, then perhaps one's efforts should be directed at producing the most efficient cabinet one can with an efficient speaker.  You'd be pleasantly surprised what 500mw-2w can do with the right speaker cab.  Do consider modest cone size (takes more current to move a heavier 12" cone), and try to port creatively.

4) Because current is an issue, the recommendation is to go for either wallwart powering or an octet of C or D cells if battery operation is desired.  These will supply nice amounts of current to permit power chords to retain their stiffness.

5) The TBA820 is a nice little kickass chip.  Also useful are bridged configurations, whether with a pair of 386 chips or one of the stereo-headphone amp chips.  In bridged mode they can deliver more wattage.

Ivana

Quote from: Steben on October 06, 2007, 09:04:02 AM
Are you insinuating nice overdrive with TDA2003?
For me yes. With a right cab and speaker.

Paul Perry (Frostwave)

Quote from: Mark Hammer on October 06, 2007, 04:29:03 PM
Do consider modest cone size (takes more current to move a heavier 12" cone), and try to port creatively.
Yes, a larger speaker has a heavier cone - but it is also coupling to the air via a larger area, so that isn't a problem.
Speaker efficiency (and the box is crucial as well, hence mark's comments re porting) is the key.
If you look inside a Pignose, you see a tiny speaker -it has a HUGE magnet, which somewhat makes up for the low power driving it - but try switching the pignose amp from the internal speaker to a LARGE stack.. you will fall over  :icon_biggrin:

Still not convinced? Try a crystal set on various speakers (via a step down audio transformer). BIG wins!

tcobretti

TDA7231 might be a candidate.  You can apparently get up to 4w with the right power supply and heat sinking.

http://www.diystompboxes.com/smfforum/index.php?topic=58731.0

BTW, generalguitargadgets.com has some amp projects and pcbs.

MartyMart

Fiddling around with the small amps is fun, but I recently built a simple 30 watt amp from a TDA2050
and ran it at 18v along with an 18v powered ( same PSU @ 800Ma ) Jfet sim, Matchbox - IIRC
Sounds really superb through the 8 inch spkr in an old Park G10r cab.
Can be ran quite quietly and still sounds great, large heat sink was required and running it from a +/- 18v supply
would be even better.
I,m probably getting 20 watts out of it, loud enough to NOT be able to stand in front of it in a small room !!!
TDA2050 data sheet was all that was needed to set it up.
MM.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com