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Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Fri May 18, 2018 4:36 am
by Joshua_S
Hello everyone,

Could you please help in choosing a audio amplifier IC for building DIY home speakers (2.1 system)? ;)

Whether to go for class AB amplifier like LM1875 or TDA7295. Or go for a class D/T amplifier like TPA3116 or TA2020 or TK2050 etc.

Looking at the datasheets of these class-AB and class-D amplifiers, the performance are looking similar, referring the graphs for THD+noice vs frequency and output power etc.

For all of these the THD was at least below 0.1% across the output power values under the given max for the chip. "THD vs Frequency" graphs were more smoother for TK2050, and LM1875 and on TPA3116 graphs THD was bit higher at around 5KHz region.

From what I have read, class-D is more efficient and so I may have a smaller power supply driving it and will have smaller or no heat sink. Thus a overall compact and small amplifier will result. But heard they have some EMI issues.

On the other hand with class-AB amplifier, sound quality will be very good and not sure if these currently available class-D amplifier are producing such sound quality. But they need bigger power supply as they are less efficient, and need a bigger heat sink, so overall it will be bit bulky.

Please help in selecting the suitable amplifier IC for DIY 2.1 channel home speaker system.

Thanks and regards. :D

Re: Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Fri May 18, 2018 5:39 am
by mediatechnology
Thanks for posting Josh. Its good to see you again.

For DIY and ease-of-use you can't beat the simplicity of the LM1875.
The LM4702 is a nice pre-driver too.

Have a look around here:

http://connexelectronic.com/product-cat ... r-modules/
http://www.ampslab.com/index.html

AmpsLab is mostly discrete. I have a Denon power amp I want to rebuild with an LM4702.
Connex has some class-D amps.

The class-D amps might require a lot of thought to layout considerations that a class-A/B wouldn't.
Connex has done that for you if you opt for a class-D.

Re: Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Fri May 18, 2018 1:14 pm
by JR.
Maybe I'm just old and tired (I've designed amps before), but I bought some cheap small (3x stereo class A/B) amps to flesh out my living room home theater. Not much power (<20W ch) but loud enough for a quiet room.

At some point I may cobble together some Hypex (class D) amp modules, They also make a switching PS for their amps. For now I'm too cheap... Wouldn't suck to find a used home theater amp that's a bargain.

JR

Re: Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Sun May 20, 2018 9:07 pm
by Joshua_S
Hello mates,
Many thanks for the inputs, what I am trying to build is for home purpose, to connect it to my TV for movies and to my mobile for songs.
My TV is having 10w+10w speakers and if raised to high volume it gets sufficiently loud. So thinking a 20w+20w+20w speaker system will be sufficient. Please comment if my understanding on watts required is ok.

Regarding the power supply for the amplifier, thinking if i can use the 65w, 19.5v laptop power supply. Is it ok or its better to go for transformer based linear power supply?

Regarding speakers, I was thinking to use car speakers, as here we can get branded car speakers like from JBL, sony etc, with 4ohm, rms 30w, and 90 - 93db sensitivity (which seems to be good sensitivity which will give loud sound with relatively less power). With branded speakers we may trust the quality of the speakers(hope so)...

Re: Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Mon May 21, 2018 6:16 am
by Speedskater
The DIY Forum has three sections on amplifier building:

Solid State
http://www.diyaudio.com/forums/solid-state/

Chip Amp
http://www.diyaudio.com/forums/chip-amps/

Class 'D'
http://www.diyaudio.com/forums/class-d/

Something for every skill level and price point.

Re: Need help in choosing a amplifier IC for DIY home 2.1 speakers

Posted: Mon May 21, 2018 9:18 am
by JR.
Speedskater wrote: Mon May 21, 2018 6:16 am The DIY Forum has three sections on amplifier building:

Solid State
http://www.diyaudio.com/forums/solid-state/

Chip Amp
http://www.diyaudio.com/forums/chip-amps/

Class 'D'
http://www.diyaudio.com/forums/class-d/

Something for every skill level and price point.
I could waste a lot of time there.... :lol:

JR