I did a vero layout with the tiny giant preamp and the TDA2030 datasheet amp.  Can someone take a look at the location of the components on the layout and point out any potential problems with how they are arranged?  (Ignore the jumpers around the output) Thanks.

 

I know that it's there to block the DC, but is the 1000uf big enough to to serve that function.  If the 1000uf works, I can use that with my 8 ohm speaker and keep the freq rolloff adequately low.

Quote from: Enzo on March 07, 2012, 07:01:35 PM
I think you will find the TL072 is rated to 18v on each rail - +18 and -18.  SO that is 36v across the IC.  Your 18v supply will not stress the 072 at all.

Thanks for pointing that out.


Is the 2200uf cap on the output acting as an RC highpass filter with the speaker?  The corner would be at 18Hz coupled with a 4 ohm speaker.  With an 8 ohm speaker, can I use a 1000uf cap (20Hz corner) here instead?

Quote from: Loudthud on March 06, 2012, 07:44:24 PM
You could use another TDA2030A to split the supply, but why? Most chips you find can't handle the current needed to drive a speaker. Unless your power supply has a center tap, a split supply is more trouble than it is worth.

I don't plan to do it.  I was just curious how it would be implemented.  That explains why I couldn't find any examples of it being done.

If I did want to split the 17V to +/-8.5V, how would I go about doing this?   I found some examples of splitting the PS using a MAX1044, but it's only rated up to 10V on the input.  Is there a chip with a higher voltage rating that I can use for this?

Quote from: Enzo on March 06, 2012, 06:12:27 AM
Why do you want a regulator?  I don't see the need.

I haven't looked at the data sheet. Was that 4w at 17v for a 17v split supply?  (+8.5v and -8.5v)?   Or did they mean +17 and -17?

I neglected to mention that I was planning to put a TL072 buffer in front of the amp.  The TL072 is rated to 18V and JM Fahey implied that the PS is unregulated so I want to be sure I don't fry the TL072.  I guess I could use a 25V max jfet like a 2N5458 instead and avoid having to use a regulator.

~4W for 17V single supply or +/-8.5V

Quote from: joecool85 on March 06, 2012, 08:33:58 AM
You could always upgrade the power supply later for more wattage.  No need for a regulator.  You will need to set it up for bipolar power though.

Why would I need to set it up for bipolar?  Are you saying I should build it for +/-8.5V now (instead of +17V single supply) so I can upgrade it to a bigger split PS in the future?

Thanks!  I'll give it a try with the single PS and see how it goes. 

I suppose I should put a regulator in the circuit.  The 78xx datasheet says "The input voltage must remain typically 2.0V above the output voltage even during the low point on the input
ripple voltage."

Does this mean that I need to use a 7815 as a fixed output regulator that will drop the voltage to 15V from the 17V coming out of the PS ?

http://www.fairchildsemi.com/ds/LM/LM7815.pdf

That will drop my output wattage down to about 2W.  Do you think that will give me enough clean volume?

I'm planning to build a TDA2030 amp with a single power supply based on the datasheet schematic driving an 8 ohm speaker.  I was initially going to power it with a split power supply from the GGG schematic, but I came upon an old printer power supply that I want to use if will work ok. I have a few questions about the feasibility of using that PS. This is just an amp to use while breadboarding, so I don't need to extract all the performance the chip is capable of.  I just need enough clean headroom to prototype stuff.

The 2030 is rated for +/-18V or +36V, 3.5A peak output current.

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000128.pdf

http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf


1)  The printer PS is rated at 13.5V/1A, but measures about 17V without a
load.  Why is it measuring that high?  Will the output voltage drop when the
PS has a load on it?


2)  The 2030 datasheet says the wattage output is about 4W with 17V, but is 1A
enough current?   


3)  The single supply schematic has a 2000uf cap on the output to the speaker,
but there is no cap on the split supply schematic.  What does this cap do?


4)  What about building a circuit to give me a split supply from the printer
PS so I can build the amp with a split supply.  That will give me the option
to swap out the PS for another PS like the GGG +/-PS if I'm not getting enough
power out of it.  Good idea?  Bad idea?  Any schematics you could point me to
for this?


5) Any suggestions for what I should be looking for in a transformer if I do
build the GGG PS for +/-18V?