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Dual or Split supply Audio amps

Started by Anirvan, April 30, 2019, 06:27:35 AM

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I came across many posts in many forums claiming that the Tda2030,2040, 2050 etc which are split supply chips can also work to their Full on Single Supply. One such claim by an author is here -


Please check this and tell me whether it's really possible or not.

I have so far failed to get max power on Single supply with these chips!  >:(  :(


A couple of Q's first,, What size & power speaker are you using?
If you are only using small speakers you won't get full power.

What is the rating of the power transformer? That is another limiting factor.
maybe post some pics of you builds :tu:


According to the datasheet, full power on a LM1875 requires a power supply of +/- 30 volts.   That's 60 volts across peaks.  Are you using a 60 volt power supply? Your schematic calls for a 30V supply, which is not going to give you full power.
Also Single-supply requires a virtual ground made by the junction of two equal resistors that only the amplifier component uses (this is an OLD stompbox trick when using op-amps with a 9V power supply).  On the circuit you provided, this is found at the junction of R24 and R25.  Here they are designated as 10k resistors, which I think possibly puts a bit of load on the power supply (but I could be totally wrong about that). I would try changing those to 47k or 100k to see if you can get a stiffer output.


Be aware as there are caveats on the full power option.  xP
The novice might miss the limitations of using 30-0-30VDC supply rails.
You will likely blow the chip if you use a 4 Ohm speaker. (it's written in the specs)

This is a small chip with small surface area and the laws of fizzy stuff tells you it cannot dissipate the heat required to run 4 Ohms at high rail voltages.
so 25 Volt rails is a good safe option. 8|
If you want more grunt then you need a bigger Amp that can dissipate the heat.