Ever wondered how they make condenser microphones? At the end of September I was fortunate enough to be invited to visit the Soyuz Microphones factory which is situated just outside the city of Tula about 2 hours drive south of the Russian capital Moscow. In this video we see how the constituent parts of the microphone are finished then brought together to form a beautiful Soyuz SU-017 microphone.

Part 2 - Finer Detail

In the first video we saw how the engineers in the Soyuz workshop turned stock material into the constituent part of the microphones. In this video we are going to see the next stages of the process and follow it all the way to testing, packaging and the all important quality control.

The first stage in the lab is to clean up the capsule backplates. A technician inspects the backplates under a microscope and using a special tool removes any burs or rough edges around the drilled holes. The backplate is then smoothed again on a special metal plate.

The team at Soyuz are very proud that they are able to gold sputter their own mic diaphragms. The gold sputtering process is quite amazing to watch. First the technician secures the thin Mylar film into a framing ring. The ring is then turned to apply an even tension to the film. The ring, along with 11 others is placed into the sputter machine, the lid is brought down and the air is sucked out of the housing. The air is replaced with Argon gas to aid the sputtering process. One by one the clear diaphragms are exposed to the beam and the gold very slowly adheres to the Mylar. This is proper heavy science and far beyond my pay grade but sped up it is very interesting to watch.

Next we see one of the technicians assemble the our SU-017 dual diaphragm capsule. The backplate is placed onto a holding jig and the newly coated diaphragm is introduced and lined up. The capsule ring is placed on the top and secured with a number of screws applied using another template jig. Once all the screws are secure the excess diaphragm material is cut away.
Lastly a small hole is pressed into the centre of the diaphragm to secure the wires that link it to the main circuit in the mic body. The two diaphragms are the brought together to form our dual diaphragm capsule.

At the same time as the mics are being built, another engineer is hand building the power supplies for the mics. The PCBs are produced locally off-site but the components are added and soldered by hand. The fully populated PCBs are then secured into the power supply housing.

The final stage of construction is the assembly of the microphone where all the handmade parts are brought together.

First the capsules are fitted to their housing and secured then the outer case is secured to the frame of the mic using the brass hemispheres which we saw being made in part 1.

The head of the microphone is screwed to the body and the body is lined up so the front of the capsule is in line with the Soyuz logo. This is just one very small part of the quality control process that continues throughout the Soyuz factory.

Each technician that works on the mics at Soyuz fills out a card so you as the new owner knows who worked on their mic. I really like this as it shows the pride the team take in their work and, if there is ever a problem, it makes it very easy to track who did what and fix the problem.

The final station the mics go to is packaging. The mic itself is put in it’s custom, locally made Oak wood box and placed into the shipping box, followed by the power supply, shock-mount and cables. All the time the parts are being given a final QC check to make sure what leaves the factory is a good as it can be.

The last thing in the box, which is the first thing you as the new owner will see if the documentation for the mic and the cards showing you who worked on your new Soyuz microphone.

I really hope you agree this has been a really fascinating journey to see how raw materials are turned into what I think is a real work of art of a microphone. I’d like to thanks the entire Soyuz team but especially Dave and Pavel for making me so welcome and inviting me to the facility.

You can find out more about the SU-017 and the entire range of Soyuz Microphones at their website.