How long before somebody makes an SWR meter for this impedance matching?
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Studio Preamp into a CB Radio
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How long before somebody makes an SWR meter for this impedance matching?
Not quite, you shouldn't try to run a high impedance mic into a lower impedance input if you care about your audio quality, But yes, you can use a lower impedance mic into a higher impedance input and the frequencies will pass.
A good analogy for people to think about on this subject is to think of a high impedance mic like a 2 inch water pipe under pressure trying to force it's way into a 1 inch opening. A lot of restrictions or impedance will happen, but a 1 inch water pipe into a 2 inch opening will pass the water with ease.
So no, if you have a 300 ohm mic for a 600 ohm mic input, there is no need for a matching transformer, but the reverse isn't true if you want your mics full audio potential to pass through especially if your mic is a high impedance like 2000 ohm.
So with lower impedance mics, it isn't necessary to exactly match the impedance input.
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Yes you are correct. I misstated above. It is acceptable to "bridge" the output of a low impedance source and not affect the freq. response much if at all. Back in another lifetime we used to ensure we had everything matched to 600 ohms and THEN take a bridge feed to something. Old habits die hard.
Here is another concept. Many high end preamps have variable impedance adjustments for mic input loading only. This is typically used for ribbon and some condenser mics. I'm sure you know all this.Yes you are correct. I misstated above. It is acceptable to "bridge" the output of a low impedance source and not affect the freq. response much if at all. Back in another lifetime we used to ensure we had everything matched to 600 ohms and THEN take a bridge feed to something. Old habits die hard.
I use a mic activator which is a non-preamp by Cloud audio to load up a ribbon mic. I usually Ioad up to 2k of input impedance to really open up the mic audio far above what EQ can do. This is highly recommended for ribbon mics. While the mic input impedance is loaded up high, the output impedance is still around 275 ohms.
You can look me up on QRZ if you would like to see a simple picture diagram of my audio chain.
I hope to get my station back up and on the air over the summer/fall with all new antennas etc. Then over the winter I hope to have time to experiment some with various microphones I have including an old RCA ribbon mic. Not sure is the ribbon is still intact or not but I am really hopeful it is. Can't remember the model number of it but I think it's either a 44BX or a 74. Been dying to get one of those on my old AM station.
I would love to have on if those coveted vintage RCA mics but they are getting a bit too pricey these days.