It's not the size, it's how you use it! ... 
I'm looking at optimising the sound from a good quality 90's keyboard at the moment, and doesn't this demonstrate that the Pro and home music worlds have got this sort of problem beat!! Manual states, 2 x 10W amplifiers, simple 6" speakers one either side, with tweeters. But this can produce thunderous levels of sound, quite deafening - no trouble doing an acoustic grand piano at live levels, would fool anyone walking past the house ... but try and do the same with humungous power amplifiers, in an audiophile setup - what a struggle it is!
I'm looking at optimising the sound from a good quality 90's keyboard at the moment, and doesn't this demonstrate that the Pro and home music worlds have got this sort of problem beat!! Manual states, 2 x 10W amplifiers, simple 6" speakers one either side, with tweeters. But this can produce thunderous levels of sound, quite deafening - no trouble doing an acoustic grand piano at live levels, would fool anyone walking past the house ... but try and do the same with humungous power amplifiers, in an audiophile setup - what a struggle it is!
tda2052 is allso good up to 15 watts,
single supply ones.. well, i think it can be built for single supply.
http://www.diyaudio.com/forums/power-supplies/120401-power-supply-issue.html
like this.
depending on Your power needs, maybe some paralelled opamps could do the trick too,
but i would not shoot for that.
lm1875 comes to mind too,
and a class-H tda chip, but that would be rare to find, and darn expensive...
most probably if low power stuff is all You want, then You could try to force an opamp into class A with Jfet cascode, and add some more capable power stage, but that would not be a real chip amp
Yes, 2052 looks good on paper and seems flexible enough to do a nice pcb and even add also a woofer chip, its double rail but I guess if one wants a good amp will most probable need it .
I’ll check and see if the chip is available locally.
Thanks for the tip.
Attached is a PCB layout which I plan to make for a stereo LM1875. After reading the spec sheet found it would make a very good chipamp so decided to give it a shot with parts that I have at hand, few mods have been done from the suggested schematic plus some notes I’ll explain.
Please note that this layout is done on a single sided 4x4” board and more than a 1/3 of it is occupied by a sheatsink that I took from an old PC board with fan that could be activated with a low voltage to give further heatsinking capacity if needed.
A separate board will be made for the split supply at around +-25V on a CLC schem including the option of a 5v reg for the fan or a 317 for variable voltage.
Notes on the layout:
Two small jumpers have been added to preserve power ground “star” configuration as much as posible.
Instead of the 100u decoupling caps I have FC’s 820u a pair for each amp with added 100nF MKP’s at the pins (not shown).
Long jumpers will be needed for the supply rails AA and BB to preserve compactness and overall symmetry for the PCB.
At the output have added provision for the use of a R + H if needed for capacitive loading I will only use a jumper there since driving only a fullrange.
Don’t have at hand an appropriate 2.2u input cap so decided to use a 4.7u and change the pulldown resistor to 10K in order to preserve the 3 Hz or so rolloff.
In reality I won’t need much power so have kept the NFB resistor at 20K expecting the best SQ following the suggested schematic by TI.
Other recommendations from TI seems more difficult to follow such as keeping power traces and wires at least 2” away from low level signal parts, on a compact layout like this is almost impossible.
I’ll appreciate any suggestions you may have on this layout so please shoot whatever you think and thanks in advance.
Antonio
Please note that this layout is done on a single sided 4x4” board and more than a 1/3 of it is occupied by a sheatsink that I took from an old PC board with fan that could be activated with a low voltage to give further heatsinking capacity if needed.
A separate board will be made for the split supply at around +-25V on a CLC schem including the option of a 5v reg for the fan or a 317 for variable voltage.
Notes on the layout:
Two small jumpers have been added to preserve power ground “star” configuration as much as posible.
Instead of the 100u decoupling caps I have FC’s 820u a pair for each amp with added 100nF MKP’s at the pins (not shown).
Long jumpers will be needed for the supply rails AA and BB to preserve compactness and overall symmetry for the PCB.
At the output have added provision for the use of a R + H if needed for capacitive loading I will only use a jumper there since driving only a fullrange.
Don’t have at hand an appropriate 2.2u input cap so decided to use a 4.7u and change the pulldown resistor to 10K in order to preserve the 3 Hz or so rolloff.
In reality I won’t need much power so have kept the NFB resistor at 20K expecting the best SQ following the suggested schematic by TI.
Other recommendations from TI seems more difficult to follow such as keeping power traces and wires at least 2” away from low level signal parts, on a compact layout like this is almost impossible.
I’ll appreciate any suggestions you may have on this layout so please shoot whatever you think and thanks in advance.
Antonio
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