We are working on an old Raytheon RR-30 here. For those wondering what they sound like, I have not used it enough to really say, but it LOVES ribbon mics. It is quite warm yet clean, and impressively flat for the era. Tracked a bass guitar cab with an SM7 through this, sounded great. I also ran a guitar into it with a DI, and WOW.
I have attached a screenshot of the current frequency response on the old trusty R&S UPD here. The yellow signal is what is being sent, green is the amplified signal. They used some good transformers. I have not tested it with the wider band generator yet, but it does an impressive job of passing low end, and high frequencies. I think I have the generator set to send 2Hz up to 22K, and the analyzer to read DC to up to 25K. The unit has generators and analyzers for up to like 100 and 300K and starting around 20Hz but I am not done tweaking here. We can look at that later. I have some noise spikes at 30, 60, 90, and 120 hz... lol. So we know what that might be. I think I have a pic of that too. In that pic the Yellow line is running about -100dbV the test units self noise, the Raytheons 30 Hz spike is like 50dB lol.
Have fun and take care everyone.
-Tony
