jaygunn
Active member
This is a pair of transformers for 2 channels of mic preamp. Each accepts a 150/600 ohm input and has a gain of 10. From the 150 ohm input the output impedance of the transformer is 15K ohms, since the impedance increases with the square of the turns ratio of the transformer. The turns ratio is 10 (so the voltage gain is 10x) and the impedance gain is 100. You can make a great mic preamp with each of these by getting the first 20dB of gain from the transformer, and then an additional 30-45dB of gain from a low noise op amp. Of course you can also use a triode or a discrete transistor circuit as well.
One of these transformers has never been connected to anything. The other I used for a few minutes to verify that my breadboarded mic pre was working okay (it was). Then it was disconnected and filed away. I had been intending to make a FETbloak discrete op amp and never completed the project, so it is time to let these like-new transformers go to someone who will use them.
Current price for these is $53.09 each plus shipping from California. I am selling them at $60 total for the pair, which includes shipping within the 48 contiguous states. Paypal accepted.
One of these transformers has never been connected to anything. The other I used for a few minutes to verify that my breadboarded mic pre was working okay (it was). Then it was disconnected and filed away. I had been intending to make a FETbloak discrete op amp and never completed the project, so it is time to let these like-new transformers go to someone who will use them.
Current price for these is $53.09 each plus shipping from California. I am selling them at $60 total for the pair, which includes shipping within the 48 contiguous states. Paypal accepted.
