10,000 uF capacitors for power supply

[Johnson777717]

Hey folks!
I need some assistance if I may?

I'm building an audio amplifier using a STK4152 II stereo amp. While the actual amp IC isn't really important here, I just thought that I would include it just in case anyone has used this IC before.

Looking at the datasheet for the circuit, the power supply portion of the circuit requires two 10,000 uF capacitors :shock:

I don't have any 10,000 uF caps, but I do have several 3300uF, 2200uF, 1000uF caps.

Is there any way around using a 10,000 uF capacitor here? I understand that I can place a few caps in parallel to each other in order to obtain the 10,000 uF requirement. Is there another way, other than purchasing the 10,000 uF caps?

Thanks for any assistance that you can provide. Have a great day!

 

[bmcculla]

Putiing caps in parellel should work and might actualy be better. Look at the ESR of your caps in parrallel and compare it to the ESR (equivalent series resistance) of a 10,000uF. Adding Caps in parallel is a commonly used way to get lower ESR.

Brent

 

[Nigel Goodwin]

The 10,000uF isn't critical, but the bigger the better.

Depending on the output levels of the amplifier, and how you plan to use it, a smaller value will probably make no difference at all. In 100W PA amplifiers, where they really get loads of hammer, 4,700uF capacitors are commonly used.

If you were making a top quality HiFi amplifier, you could do with large capacitors, but as you are using an STK IC it doesn't really matter much.

 

[Johnson777717]

Thank you both for the replies, and the advice.

Just as a backround, I'm making this amplifier to drive 30-40 watts tops and I plan to use the amp with my computer sound system, so I won't be demanding all that much from the amp, hence the IC.

I'll put together a breadboard of using 3 3300uF caps in parallel, and another breadboard using a 4700uF to see if I can notice any difference.

I was also reading an article from Elliot Sound Products about capacitance multiplier power supplies. See link below if you wish. Have you folks had any experience with this type of circuit?

Thanks again!
**broken link removed**

 

[Klaus]

[quote

I was also reading an article from Elliot Sound Products about capacitance multiplier power supplies. See link below if you wish. Have you folks had any experience with this type of circuit?
Thanks again!
**broken link removed**[/quote]

I had used something like that years ago to get rid of some annoying hum in an amplifier I had built. It did the trick! In those days the big, low ESR, low ripple capacitors were not so common nor cheap.

 

[Nigel Goodwin]

Just as a backround, I'm making this amplifier to drive 30-40 watts tops and I plan to use the amp with my computer sound system, so I won't be demanding all that much from the amp, hence the IC.

I would expect just a 3,300uF would be plenty.

I've got a commercially built PA slave amplifier, rated at 100W RMS into 4 ohms - it uses a single ended supply, with just one 2,200uF capacitor.

 

[mozikluv]

capacitors

hi,

a quality cap of 3,300uf in parallel will do. parallel caps lowers the esr. :wink:

 

[Johnson777717]

Thanks again for all of your help. You folks are awesome!