I worked in the same building as a guy who, as part of amplifying a signal on a test board, needed a gain of 5X. He choose to use an operational amplifier (opamp) because after all how hard are opamps to use??
Problem was his choice of resistors. He ran afoul of the finite output current of the opamp.
Most opamps give you 10 or 30 or 30 milliAmps output current, because people use moderate values of resistors such as 1Kohm (which has only 4 nanoVolts/rootHertz noise, which is 4,000 nanoVolts or 4 microVolts or 0.000004 volts RMS in 1MHz bandwidth) or 2Kohm or 10Kohm or 5.01Kohm (because they wants 5.000Kohm and 5.01K was in stock).
This engineer, excellent and focused and dedicated and effective in his usual tasks, did not use Ohms Law to compute the current ---- after all, these are opamps and there
are no application issues with opamps, right?
So, to get the gain of 5X, using inverting opamp topology (circuit), he chose to use
ONE OHM and FIVE OHM resistors.
This would have been fine, for input signals less than 10 milliVolts or perhaps 20 milliVolts.
But at one volt input, the opamp needed to handle 1 amp, or 1,000 milliAmps.
He, by not reading the datasheet of the OpAmp, or likely having no prior experience with opamps as NOT infinite power devices, was surprised.
Summary: lower value resistors, such as the very popular 51 ohms (5-1 ohms) have much less random electron-movement-thermal-agitation voltage noise; thus in reading back the music from vinyl discs, one of the design parameters for the PreAmplifier is LOW NOISE.
I've seen vinyl playback amplifiers using 4.7 ohms resistors as part of the circuit directly connected to the Moving Coil pickup cartridge.
One caveat is the non-zero resistance of PCB copper foil. Standard thickness foil, which is 1 ounce of copper per square foot of PCB area before etching, is 0.0014 inch thick (or 35 microns), and that foil has 0.00500 ohms (yes, 500 microOhms) resistance per square of foil. Thus a PCB trace of size 0.2 inches long and 0.005 inches wide, has 40 squares of foil and 20 milliOhms resistance.