Since the stereo ribbon mike required phantom power I assume it included a mike pre-amp in the unit which presented the required termination needs.
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> On Aug 30, 2014, at 4:28 PM, Paul Stamler <[log in to unmask]> wrote:
>> On 8/30/2014 1:03 PM, DAVID BURNHAM wrote:
>> Certainly they're still making ribbon mikes. But I have compared a very high-end stereo ribbon mike with an AKG C422, (the first solid state stereo mike that AKG produced when they discontinued the C24), both in an MS configuration, and the quality of sound, to my ears, from the C422 was vastly superior to the ribbon mike and, of course, the C422 isn't limited to just bi-directional pick-ups. I think there are also ribbon mikes which have other polar patterns but I don't think they're switchable.
> It's worth noting that classic ribbon mics (e.g., RCA) were designed to be fed into a mic preamp with an input transformer that fed the grid of a triode or pentode tube, *without* a terminating resistor on the transformer. This means the mic is presented with a relatively high load impedance, significantly higher than the 1500-2400 ohm input impedance of modern preamps. There are a few modern preamps that will work well with classic tube amps (the AEA device, designed as a companion to their RCA-inspired designs, and the Benchmark mic preamp introduced about three years ago. I did an experiment with an old RCA ribbon; I operated it into a good modern preamp from Grace, and into the Benchmark. There was no contest; the mic, used through the Benchmark, had an entire octave of high frequency response that was missing through the Grace.
> David's compariaon of a pair of ribbon mics with an AKG stereo condenser mic may have been skewed, if the ribbon mics were used with typical modern mic inputs. They weren't built with that expectation. I'd love to hear the same experiment repeated using something like a Benchmark preamp on the ribbons.
> And David, you're quite correct that there are ribbon mics available with other than figure-8 polar patterns; Beyerdynamic makes several with hypercardioid patterns. And you're right; they're not switchable.