rubinstu
Active member
- Joined
- Jan 10, 2019
- Messages
- 37
I was hoping that some of you experienced folks could offer some general comments on my DIY ribbon mic project.
Here is the basic overview. The mic itself is two ribbon motors set in a Blumlein configuration. Most of the mechanical parts are laser cut 3 mm plywood (because when all you have is a hammer, everything looks like a nail!).
I plan to make a simple built-in pre-amp (actually two, one for each channel) which is basically a copy of a FETHead to get some gain, lower the output impedance, make the impedance that the ribbon sees more predictable, etc.
Some specific notes and differences from your basic FETHead are:
Some big open questions include:
Here is the basic overview. The mic itself is two ribbon motors set in a Blumlein configuration. Most of the mechanical parts are laser cut 3 mm plywood (because when all you have is a hammer, everything looks like a nail!).
I plan to make a simple built-in pre-amp (actually two, one for each channel) which is basically a copy of a FETHead to get some gain, lower the output impedance, make the impedance that the ribbon sees more predictable, etc.
Some specific notes and differences from your basic FETHead are:
- Transformer will be mounted on the PCB. This is basically to make construction and testing easier.
- Two not-populated resistors (R4 and R5) which, if populated, let me inject phantom power for testing the circuit (J10, J11).
- Additional pads for testing, alternative inputs (like skipping the transformer), etc.
- Two-sided PCB with bottom sided being entirely (or mostly) ground.
- There are three extra holes around the transformer "box" where I may use wire ties or something like that for holding the transformer in place, maybe with some hot-glue as well.
- In simulation, driving a 3K-ohm load, there is a voltage gain of about 22x (26dB).
Some big open questions include:
- How to shield the transformer and other sensitive parts
- To to mechanically assemble is all while still having the ability to take it apart for test, repair, etc.
