Rode K2:
Background information: Most high end studios have wonderful tube mics that are the envy of every project studio owner. The good news is due to newer technology, lower cost tubes mics are coming out of China by many companies that included Rode. With cheap labor in China, companies are able to manufacture improved sounding mic's at low costs. Rode, in wanting to be more compeitive - and to stand out from the pack - decided to move their manufacturing back to their home base in Australia.
Rode bought expensive high precision finishing machines and computer controlled metal lathes. Most of the mics are put together by automated machines, although some parts still need to be done by hand. Every mic is tested and has a 24 hour burn before it leaves the factory. With this format, they have much better quality control and with manufacturing a thousand at a time, they are able to keep their costs down.
Rode previoulsy released two low cost tube mics; the NTV and NTK. In wanting to improve on the NTK they used an improved capsule. To design a good capacitor capsule is extremely complex and very expensive. Many paramters are needed to consider from the diaphragm material, shape, thickness, and tension. There is also spacing on the back plate, signal connection, isolation dielectrics, polarizing voltage and damping arrangement. Not to mention rear chamber labyrinth, which affects the linearity of the off axis frequency response. I must say that the new K2 capsule design which is now also included in the NT2-A is a solid, very well built capsule in it's price range.
Once the capsule has been designed, it has to be mounted to a mic body. The grill size, and shape all come into play on the tonality of the capsule, there is the impedance converter circuitry, powering circuitry, and output circuitry, all of which affect the sound of the mic further.
The K2 circuitry includes the use of a 6922 dual triode tube, with a Class A configuration and holds the tube with a porcelain sockets with a plastic tube clip. A double layer stainless steel grille mesh is then installed on the mic which helps block radio frequencies while giving a attractive matte nickel plated finish. A good pop filter is highly recommended when recording vocals with it.
Another improvement over the NTK is having variable modes from Omni, figure-8, and caridiod, all which are controlled on the external power supply. The frequency range is 20Hz-20kHz, with no real peaks with the exception of one at 5 kHz in cardioid mode and a more subtle peak at 12 kHz in Omni mode. The signal to noise ratio is 81 dB, which is lower than many solid state mics.
Rode's founder, Peter Freeman, found the rejection rate of capsules is way down since the manufacturing days in China. The consistency between two mics are now so close, which can not be said about many Chinese mics. A six-milcron, gold evaporated Mylar diaphram are used as well as a secret process to age the mic to improve the precision.
The K2 is very well made for a mic in its price range, well thought out and has high quality control. But how does it sound? I compared the K2 against the AKG Solid Tube, Audio Technica 4060 and Rode NTK, all which are in similar price range (under $1,000). In comparison with the NTK, both give the subtle tube sound with the K2 having a slightly smoother top end. It also had less sibilance compared to the NTK. With a good shock mount included and not being a fixed cardioid-pattern as the other mic's, I found the K2 to be a real winner. It does not have a dark tube sound, or a tubby sound as with some inexpensive tube mics. Since it has more of an open and less colored sound, this mic can sound great on both male and female voices as well as other applications, including acoustic guitar, and wind instruments.
I found it gave a gentle smoothness to vocal and acoustic guitar tracks that my Blue Blueberry or Brauner Phantom mic could not give. The Solid Tube and 4060 both have a darker sound over the K2 though both had a nice sound; I feel their use would be more limited due to the stronger color character of both. Though this mic will not give you the sound of a high priced Neumann or Bock, the K2 is a mic that can be used successfully in many situations. The only thing I could find fault with is that the mic did not come in a nice wood box. But in order to keep cost down, they put the mic in a hard plastic case that included a cable, transformer, shock mount and mic. If you are looking for a nice sounding tube mic in the below $1,000 range, I recommend checking out the K2.