Hello dear DIY community,
First, I would like to thank you all for the many great contributions here in the forum. These have helped me a lot with my ribbon mic mods. Now I would like to start my first thread and maybe I will help someone with it.
I have a few questions regarding my DIY RCA BK5 mic. But first I wanted to tell you a little bit about the origins of the built.
After modding a few Ribbon mics, I tried to build my own one. And because there is no real cheap RCA BK5, I decided to build this. I´ve read a lot of things about the BK5, studied drawings and pictures of it and it took a long time before I even started.
It took me a lot of time to choose the different materials and to make the individual components, but it was a lot of fun. I think I built it every now and then for half a year and improved a lot of things. Like the clamps. After using acrylic with a copper strip and getting a signal that was way too weak, I made clamps out of copper that gave a much stronger signal.
The mic body is from a broken Stagg condenser mic. The labyrinth (1 meter long) made of aluminum, the motor made of acrylic glass, phase shift openings with mesh, 4 neodymium magnets (25mm x 4mm x 4mm), 1.8 micron corrugated ribbon foil, thick copper wire, blast shield made of two layers of perforated grid (2mm holes), plastic and fabric. As a test, the transformer is a cheaper one from a T-Bone RB500. A Lundahl LL2913 has already been ordered.
In my opinion, the microphone sounds really great. Whether electric guitar, acoustic guitar or vocals. Really nice forward sound with a minimal proximity effect, for a ribbon. And a realy tight pattern. But my signal is about 10 -14db weaker compared to my modded Beyerdynamic BM 85 (Beyer M500) or Bumblebee RM-6.
Now here´s my questions and maybe someone can give me a few tips:
Would it help a lot if I included a magnetic return circuit? As marked in red in the picture. I only have access to 6mm gauge cold rolled steel. In the bottom plate would be a hole for the labyrinth path.
Would it help if I integrated 1 or 2 additional magnets on each side of the magnetic return circuit? Marked in black as shown in the picture.
How much db increase can I promise from it?
Unfortunately, I can't do the magnetic return circuit around the copper brackets, because I don't have any space in the head basket.
Thank you very much and best regards!!!
Jan from Franconia, Germany
First, I would like to thank you all for the many great contributions here in the forum. These have helped me a lot with my ribbon mic mods. Now I would like to start my first thread and maybe I will help someone with it.
I have a few questions regarding my DIY RCA BK5 mic. But first I wanted to tell you a little bit about the origins of the built.
After modding a few Ribbon mics, I tried to build my own one. And because there is no real cheap RCA BK5, I decided to build this. I´ve read a lot of things about the BK5, studied drawings and pictures of it and it took a long time before I even started.
It took me a lot of time to choose the different materials and to make the individual components, but it was a lot of fun. I think I built it every now and then for half a year and improved a lot of things. Like the clamps. After using acrylic with a copper strip and getting a signal that was way too weak, I made clamps out of copper that gave a much stronger signal.
The mic body is from a broken Stagg condenser mic. The labyrinth (1 meter long) made of aluminum, the motor made of acrylic glass, phase shift openings with mesh, 4 neodymium magnets (25mm x 4mm x 4mm), 1.8 micron corrugated ribbon foil, thick copper wire, blast shield made of two layers of perforated grid (2mm holes), plastic and fabric. As a test, the transformer is a cheaper one from a T-Bone RB500. A Lundahl LL2913 has already been ordered.
In my opinion, the microphone sounds really great. Whether electric guitar, acoustic guitar or vocals. Really nice forward sound with a minimal proximity effect, for a ribbon. And a realy tight pattern. But my signal is about 10 -14db weaker compared to my modded Beyerdynamic BM 85 (Beyer M500) or Bumblebee RM-6.
Now here´s my questions and maybe someone can give me a few tips:
Would it help a lot if I included a magnetic return circuit? As marked in red in the picture. I only have access to 6mm gauge cold rolled steel. In the bottom plate would be a hole for the labyrinth path.
Would it help if I integrated 1 or 2 additional magnets on each side of the magnetic return circuit? Marked in black as shown in the picture.
How much db increase can I promise from it?
Unfortunately, I can't do the magnetic return circuit around the copper brackets, because I don't have any space in the head basket.
Thank you very much and best regards!!!
Jan from Franconia, Germany
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