If you want to do even a simple repair on your microphone, it is good to know that there are two different systems of screws that are used, the US system and the Metric system.
US Machine Screws are described 0-80, 2-56, 3-48, 4-40, 5-40, 6-32, 8-32, 10-32, 10-24, etc. up to 12, and by fractional inch beyond, such as 1/4-20, 3/8-16 and so on. The first number designates a diameter, the second is the number of threads per inch (TPI). Typically the description will also include the length noted as (Example 10-32X1/2.) So the screw size comes first, then an X, and then the length in fractional inches.
Metric Screws
Smaller Metric screws are Designated with M and then the diameter in millimeters. Standard sizes are M1, M1.2, M1.6, M2, M2.5, M3, M4, M5 and so on.
Typically the description will also include the length noted as (Example M4X6). So the screw size comes first, then an X, and then the length in millimeters.
There are several common different types of heads. A flathead screws into a countersunk hole, and when screwed in all of the way, the top of the head is even with the panel, a round head is a rounded head that sits above the panel, and a pan head is like the bottom of a pan that sits above the panel. Screws can be slotted, Phillips, TORX or other types, depending on the tool needed to tighten and remove them.
Microphone mounts in the United States have a 5/8-27 thread. In US designation, this means that the hole is of 5/8 inch diameter and the thread pitch is 27 threads-per-inch.
You may have noticed that many microphones ship with an adapter screwed into this mounting hole. This adapts the microphone for the European standard for microphone stands and mounts which is a US standard 3/8-16. That’s a 3/8 diameter hole with a pitch of 16 threads per inch.
5/8-27 to 3/8-16 Mic Adapter
If you needed to make a special mount for your microphone you could use this adapter and a standard 3/8-16 bolt which is available at any hardware store. Why the European standard mount uses a standard US sized mounting screw is a mystery to me since everything else over there is metric.
If you have any older Electro-Voice microphones like the RE-10 or RE-11, the RE-15 or RE-16, the 627A or a 635, you might have noticed that the windscreen is mounted to the microphone with a strange little screw that defies removal. This is a crown head or more specifically a #4 Gulmite screw.
The easy way to remove the screw is with a #4 Gulmite driver. The problem is that you cannot buy a #4 Gulmite driver anywhere. They show up on eBay once in a while, usually priced at around $50. Unless you repair many older EV mics this is likely a poor investment.
Removing Gulmite Screw with Vampliers
There is another solution, however. I discovered a tool, made by Vampire Tools, the Vampliers VT-001-5, which is a screw extraction pliers. These are designed for removing stripped screws, but they work extremely well for removing the Gulmite screws on older Electro-Voice microphones.
They also work very well for their designed use of removing stripped screws that can no longer be turned by a screwdriver. If you’ve ever repaired some of the newer imported microphones, you have likely run into this. Many of them use screws made from extremely soft metal and if you’re not careful, they will strip easily.
This has become one of my favorite tools. It’s available on Amazon where I paid about $27.00 for it and it has been worth every penny.
Microphone manufacturers seem to have a thing about being confusing about model numbers. The Shure 55 has been around since at least the 1940s and in many different incarnations from the original “fat boy” to the latest 55SH with its Unidyne 3 cartridge. AKG may have set a record with the many different versions of the venerable 414.
RØDE is no different with the NT1 which was their first studio condenser microphone. They then developed the NT1A. and now have released their new NT1 which has little in common with the original NT1 except for the headbasket. The new NT1 is far superior to the old one with a self-noise of just 4.5 dbA and a very smooth response as opposed to the original one’s hyped high-end response.
I see confusion on the forums all of the time where people think the new mike is the same as the old, a Chinese import with a hyped high-end, when in reality this latest version of the mike has a custom designed, edge-terminated capsule, and the capsule and the microphone are all built in RØDE’s factory in Australia.
My dislike for the name aside, this microphone is an amazing value and I would highly recommend it. It needs to be in your microphone locker.
We’ll take a look inside the new RØDE NT1 in this first new video of our “Inside” series.
Here are the photos of two older Cascade LDC microphones. The MX-22 is a cardioid only microphone while the MS-33 is a multipattern mic. I acquired the MX-22 from eBay and shortly thereafter acquired a pair of MX-33s on eBay. The MX-33s were from the estate of the late Gary Loizzo who was the lead singer of The American Breed, formed in the mid-1960s. Loizzo then went on to start his own recording studio called ‘Pumpkin Studios’ in the early 70’s and become a two-time Grammy-nominated recording engineer.
There is absolutely no information on them from Cascade. I assume that they were imported from China and were a generic microphone that was customized. I tried a little more research and discovered that they were built by Feilo in China. Feilo describes their services as follows: We specialize in contract manufacturing of microphones for distributors, retailers and manufacturers seeking to private label our products or outsource their manufacturing.
The MX-22 appears to be a Feilo Z-2200 and the MX-33 appears to be a Feilo Z-3300. The microphones appear to be identical, but I don’t know if any of the components had different specs. According to Matt McGlynn at Recording Hacks, the MX-33 and Feilo Z-3300 are identical to the Advanced Audio CM-87, at least from looking at the pictures. Both of the microphones feature discrete class-A circuitry and a transformer-coupled output. They have a 1.07″ diameter K67 center-terminated type capsule.
The mikes are packaged in an aluminum case and come with a shockmount.
I’ve had this Electro-Voice mike in my collection for a number of years, but never bothered to test it since it had an Amphenol MC-3 connector on it and I didn’t have the proper cable. But, I acquired a box of Amphenol connectors recently, so I thought it was time to check out this classic mike.
This is a large microphone, comparable in size to my Shure 556 “fat-boy, Elvis” microphone. It weighs in at about 2 ½ pounds. The best I can tell, it first appeared on the market in the late 1940s.
According to the EV spec sheet:
The CARDYNE microphones are cardioid unidirectional dynamic types operating on the E-V Mechanophase principle. They utilize dual phase shifting diaphragms to produce a high degree of uni-directivity at all frequencies.
The CARDYNE models are designed for extremely accurate reproduction of music and speech. The directivity gives it unusual versatility in increasing the working distance from the user by reducing reverberation and acoustic feedback. High output provides an excellent signal-to-noise ratio for broadcasting studio pick-up.
My unit is in excellent physical condition externally, but I decided to open up the mike to make sure the insides were OK before wiring up the new cable. Two screws on the back loosened the rear of the case and two screws under that loosened the front cover.
Electro-Voice 726 Cardyne 1 Microphone, internal back view.
The insides were clean and not corroded, but all of the rubber shock-mount material had hardened and some of it turned to powder. Since the cartridge assembly just flopping around inside the case, I needed to replace all of the shock-mount material.
This microphone achieves its cardioid directionality by means of a resonance chamber that is part of the dynamic cartridge assembly. This assembly rests against a block of sponge rubber that is about ½ in. thick, 1 inch high, and two inches long. I was easily able to cut a replacement piece from a piece of ½ rubber that I had and glued it into place. There were a couple of bumpers on the front of the cartridge assembly that rested against the front of the case. These I replaced with pieces of self-adhesive rubber that I cut from a sheet that I bought from a craft store.
The shock mounts that held the back of the resonator to the mike frame were not as simple. What I needed were eight ½ inch diameter rubber washers, ¼ inch thick, with a ¼ inch hole in the center. I used a hole punch to punch the ½ circles out of a sheet of rubber, and then punched a ¼ inch hole in each one of those. These were close enough in size that I was able to re-assemble the shock mounts with the new rubber pieces, tighten the screws, and verify that is worked properly.
Electro-Voice 726 Cardyne 1 Microphone, internal front view.
I double-checked the wiring inside of the mike to make sure that I hadn’t broken any wires, and then put the mike back together. I didn’t have any silk or thin foam to replace the windscreen inside the shell, but it was in fairly good shape, so I’ll save that for a later date. I then used my Dremel tool with a brass brush to remove oxidation from the exterior of the mike, and it cleaned up nicely.
I wired up a new cable for the mike to go from the Amphenol connector on the mike to a standard male XLR connector. I set the impedance switch on the back of the mike to “Low” and plugged the mike in. It worked.
Amphenol MS-3 connectors.
Then, into the studio for some comparative recordings between this E-V mike and the Shure 556. The E-V is brighter and has a higher output than the Shure. Both mikes seem to have a significant amount of distortion. I am guessing that the capsules in both mikes are showing their age and may have some damage. Replacement capsules of the same type are not available. I could upgrade to a newer capsule, but then they would no longer be vintage mikes.
So, I’ll just be on the lookout for NOS capsules on eBay. There was a NOS capsule for a Shure 55S on eBay this week, but the mounting is entirely different that the 556, so I passed on it even though it is probably the same capsule. These mikes will be mostly for decoration, except for that occasional funky recording project that pops up now and then.
What is interesting is the amount of mechanical apparatus that was needed back in the 40s to create a directional mike. My new Electro-Voice N/D 468 microphones provide hyper-cardioid directionality and great sound in a package that has probably 1/8 the size of the old 726. We’ve come a long way in the past 70 years!
Internal view of the microphone showing the wiring of the impedance switch and the transformer.
