Easy ACTIVE Ribbon..?

[merseymale]

Hi!

I have a spare Ribbon Motor and 2 condensor mics with broken capsules... I was just waiting for the right transformer to make a ribbon mic outa all these ;-)

I've built Dynamic/Moving Coil types before out of bits & pieces but now never a condenser or ribbon -then I got an idea!

Can I just connect the ribbon in place of the condenser element?
i.e: is the circuit just a kinda Pre Amp?

Also this Alctron ribbon motor/element has FOUR wires coming of it but 2 connections to the ribbon itself- WHY?

Thanks for you thoughts in advance

 

[merseymale]

Bump

 

[ecc83]

"Can I just connect the ribbon in place of the condenser element?
i.e: is the circuit just a kinda Pre Amp?"

No and not really.

The electronics in a capacitor mic are largely just an impedance converter and one moreover with a massively high input impedance. We are talking GIG Ohms here!

Such amplifiers are not optimized for low noise with a low impedance source and a ribbon, even after a transformer is very low Z and you need VERY low noise levels. Cap mics get away with "noisy" unity gain amps because the signal level from the capsule is quite large being at least 20dB more sensitive than a dynamic.

You could Google about for ultra low noise amp circuits but the basic principle of low noise is low circuit resistances. That means higher currents and that does not sit well with the limited current available from phantom power. Yes, you can use DC-DC converters to get lower voltages at higher currents but time, cost and hassle make all this a bit pointless give the cost of a Cloudlifter?

Simplest way to get a 12dB noise free lift from a ribbon mic is a good quality transformer. Sowter make one such, a 1:4 ratio jobbie for about 40quid.

Dave.