Reply to thread

Help Support GroupDIY Audio Forum:

Message: [QUOTE="matthieu68, post: 977252, member: 65752"] Hello, in my learning on audio circuits I aim on several points of course, but I would like to see more clearly some of them already. This is the choice of resistance values, take for example the input and feedback resistances on an opamp, the resistance values will determine the gain of the opamp but ... We can achieve this with several values, for example for a unity gain we can use 47k / 47k or then 10k / 10k, then what should be taken into account for the choice of the resistance value? Douglas' self book talks a lot about Johnson noise which is higher with higher value resistance, so why not always go for small values? This question is also valid for the choice of values for voltage divider, drain resistors etc ... Another point concerns the capacitance of the capacitors, they are placed in the audio path to filter the direct current according to the opamps used, I could read that their values do not affect when they are in the audio path (low voltage) Is it true ? The capacitance of the Capacitors has an influence if we put a drain resistor just after that forms a filter, Ok so we calculate what we need not to filter the audible band. But when should we put a drain resistor? I see circuits with and some just with capacitors without drain resistance, except I could read that without drain resistance, the capacitors could remain charged and make "plop" During an action of a Switch for example . So how do you determine this? Thanking you [/QUOTE]

Verification

Reply to thread

Help Support GroupDIY Audio Forum:

Join the conversation!

Register today and take advantage of membership benefits. It's FREE!

Don't like ads?

Did you know that registered members can turn off the ads?