smh69 wrote:would like to feed a non powered microphone (like pc headset type) into a mixer over a cd playing.
do i need a pre amp and low power amplifier?
I have built a pre amp and a TDA amplifier but the heatsink i put on the amplifier gets so hot and after a while distorts because its too hot.
Anyone see on a cheap build website like this a
https://www.icrfq.com/products/ more suitable device?
Hi.
Supposing you use a microphone pre amp and a TFA power Amp:
Having no other signal input to the TDA-Amp, but just the pre-amp connected and the TDA-hestsink hot: This might be oscilllation of the pre-amp
and requesting high current draw into the TDA:
1. checkt the correct power/voltage to the TDA and the pre amp as well.
2. The pre amp can be checked simularly. Check amplifying factor by an input signal of 2-10mV (or microphone) and check
for AC output signal with a digital MM. Or, just put yr finger tip to the hot input.
3. Check the TDA :-with shortened singnal input- and correct pwr supply?:
Still heating >> alsmost certainly DEFECT, due to HF or too high input signal(s) Check the specs, print board and replace
Ambient temp or little more: Connect to (a) speaker(s) you must not hear any 'hiss'-sound:? Might be still correct TDA
Try to connect to a sound source at low volume level.
4. If the TDA seems correct you might gif it an input signal from e.g. the head phone jack of some radio/old mobile phone.
Doing so, you check for distorsion parallel to increasing volume.
Several good pre amps are for sale online.
Often you do need just a handfull of external parts. But... all depents on the source and your requirements.
Best way however for both amps; use a scoop and a tone generator or an -injector.
>>
if you have any questions, always give detailed info, such as TDA....., pre-amp, based on... power supply V/A ... microphone..... <<
Maybe you find a proper solution at the site in my footer, otherwise here:
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https://nl.mouser.com/search/refine.aspx?N=11227392-
https://www.reichelt.de/ICs-TA-TSA-/2/i ... OUPID=2916-
https://www.alibaba.com/product-detail/ ... 38d29DZ9GAGood Luck!