Noise is speced on mic preamps as the equivalent input noise or EIN. It's the sum of gain plus noise.
Any transformer input design will limit EIN to about -127 db with a 150 ohm source impedance due to transformer insertion losses.
The amount of available gain isn't a gauge of the noise floor of a given preamp. The EIN spec is. Look for it, if it can be found.
Ribbons are not noisy. They are low output so the preamp requires more gain = more noise. Some ribbons are 50 ohms impedance. That makes the transformer input preamps worse as all audio mic input transformers are speced at a 150 ohm source impedance. The noise floor will degrade further at 50 ohms.
Compared to a transformerless design, 50 ohms is actually better EIN, on my preamp it's -133 db EIN. That's 6 db less noise, or 1/2 of the iron front end. Take 6 db of noise off that ribbon mic and it's pretty quiet.
