Some times you need to amplify a signal that is too low for your needs. It most likely will be temp but could be duplicated for a final project use as needed.
It could be any gain (in signal level) from 1 (just a buffer) to near 1000 times (X). In fact, it can be very easy to make it adjustable to several selectable gains. I will use 10, 20, 100 and 200 in mine and even make the component that sets the gain (resistor) replaceable so I could make a very exact gain or a times 1 buffer if I want. I will use a Altoid metal can but any metal box is good. Metal so the amp is shielded from electronic noise. Not so necessary at times 10 or 20 and a fairly high signal but needed with 100+ gains or very faint signals. I will also use Metal film 1% resistors to keep the noise down too, for the same situations. This allows me to have a pretty precise gain which is some times necessary in testing things. |
Above is a picture of many of the pieces I collected to build my X amp (times amplifier). It will be battery operated to reduce noise even more. Power supplies using the wall AC and then cut down to what is needed is notoriously noisy and expensive to do right. The trade off here is a very restricted maximum signal output. You could use 2 9v batts either in plus/minus supplies (other advantages to that) or just series them to 18v. Note that 9v batts are not really 9v but anywhere from 9 to 7 and rarely 9. Look for high quality batts for higher voltage, longer lasting and rechargeable. I think there are even Lithium ones now.
Below is a picture of a partially assembled X amp. The input (on left) is 3.5mm mono jack. the output is RCA (on the right). The switch will turn power on and off.
Below is a picture of a partially assembled X amp. The input (on left) is 3.5mm mono jack. the output is RCA (on the right). The switch will turn power on and off.
TBD...