owel
Well-known member
I'm making a preamp that I planned to be powered from a single 48V supply... powering the preamp and the phantom power.
Well, I found a problem! Problem is, I'm using dual 22V toroid transformer and the most it can do is 47VDC unregulated. (I wired the secondaries in series 22-0-22)
I checked prices of dual 24V or higher transformer and there's a big jump in price from 22VAC to 24VAC... like from $16 to $55!!!! I don't want to pay that much for a power transformer.
I've tested my preamp running on 40VDC and it works fine... mic phantom power also works on 40VDC with no problems. So I'm thinking of just using dual 22V toroids and regulating it to 44VDC. I know it will work.
Question: So why is it phantom power for mics are specified at +48V? I see some mic specs that will work for phantom power voltages less than that. Who started this 48V convention? Is this a hard rule? If your equipment doesn't supply 48V phantom power to its mic, is it considered inferior?
In my opinion, if the mic works fine, I don't need exactly +48V phantom... 40 or 44 will do. So where did this 48V phantom power convention came from?
Well, I found a problem! Problem is, I'm using dual 22V toroid transformer and the most it can do is 47VDC unregulated. (I wired the secondaries in series 22-0-22)
I checked prices of dual 24V or higher transformer and there's a big jump in price from 22VAC to 24VAC... like from $16 to $55!!!! I don't want to pay that much for a power transformer.
I've tested my preamp running on 40VDC and it works fine... mic phantom power also works on 40VDC with no problems. So I'm thinking of just using dual 22V toroids and regulating it to 44VDC. I know it will work.
Question: So why is it phantom power for mics are specified at +48V? I see some mic specs that will work for phantom power voltages less than that. Who started this 48V convention? Is this a hard rule? If your equipment doesn't supply 48V phantom power to its mic, is it considered inferior?
In my opinion, if the mic works fine, I don't need exactly +48V phantom... 40 or 44 will do. So where did this 48V phantom power convention came from?