As keen readers of the site may know, I cannot abide using a bad microphone when there are so many good mics that are plentiful. You can get a great sound out of something that costs less than $100 bucks, but when you dig deeper than that into the world of DIY, the value proposition gets more interesting. There’s a rich, gorgeous world out there of hand crafting microphones, but that is a daunting topic for another blog. Instead, I wanna tell you about a simple, 10 minute modification that takes a relatively inexpensive microphone and brings it shockingly close to one of the greatest microphones of all time: the Neumann U 87.
The mod in question comes from the depths of the GroupDIY forums – a go-to destination for DIY microphone information. Here you can unlock all sorts of information about who makes the best capsules, replica bodies from alibaba, and full replicas of older PCBS. This particular mod was originally pioneered by well-known tinkerer and poster kingkorg, who discovered in 2017 that if you take AKG Perception P220 (and to an extent, many other mics in the same line) and swap or add a single capacitor, you get very close to the legendary U 87.
If you don’t know the Neumann U 87, it’s one of the most famous vocal microphones ever made. It was introduced in 1967, going through various iterations. The current model, the U 87 Ai, goes for about $3,595, slightly less used. There are countless clones of it – tinkerers love to try to make them from scratch. The AKG Perception, on the other hand, costs about $140 new and far less used. The reason this mod works is that much of the AKG Perception line is a close replica of the U 87. The problem is that the microphone capsule, while quite good on its own, is slightly brighter than the one being cloned. This one capacitor mod fixes that. While it does not make the mic identical to the Neumann (there is more to mic design than a circuit, for example the body and the headbasket) it gets it very close for $140 plus one mouser or digikey order. In a direct shootout, it’s kinda shocking.
You can read the full group DIY thread yourself. Basically you open up the mic, remove the stock 220pf stock capacitor, and swap in a 680pf capacitor (or 870pF for a sound closer to the u67). It can be done with either a cheap film capacitor, or something pricier like Wima FKP or MKP. Others had luck with 0805 NP0(C0G) surface mount capacitors. But you don’t need a fancy capacitor for it; any ceramic cap will do.
If you are a bit wary of desoldering, which is unquestionably the most annoying part of working on electronics, people in the thread report that you can simply add an additional 470pF capacitor in parallel with the one already there, no desoldering required. This is what I actually ended up doing.
Do I need a Neumann clone? Not particularly. I mainly use dynamic mics and have more than enough of those. But because the AKG Perception series is one of the best selling mic lines out there, and tons of them have entered circulation, I was able to score a beat up Perception 200 for $40 dollars on eBay. Secondary markets are lousy with these things, and it is a cheap way to experiment and pass the savings on to you, the Aftermath reader. What’s more, my good friends at the Skulltenders podcast needed a condenser mic, and were able to snag one. It worked so well that my friend who did the mod for them got one herself.
Doing the mod was comically easy, at least for me. You open up the body of the mic by using a pair of pliers to unscrew the ring securing the shell. Once you open it up, everything is already there for you; no need to remove the boards, the capsule or even the headbasket. It was as simple as soldering a cheap 470 pF capacitor over the existing capacitor. It should be noted that the PCBs for the P200/P220 are slightly different from the P400/P420 and so the capacitor you need to solder over is in two different places depending on your model. Also, not all mics in the Perception series appear to be compatible (the Perception 120 is a different mic altogether, and the Perception 820 is a tube mic).
In a side-by-side comparison, the results blew me away. The hash tinniness of the mic that held back an otherwise great capsule is no longer present, instead exposing a rich low end. It turned an already well-liked microphone into something I would be proud to give to any vocalist. Is it a Neumann? I don’t think so, and also I don’t have one for testing because I don’t have $3,595 burning a hole in my pocket. But it’s certainly worth the $40 dollars plus maybe $10 dollar bulk capacitor order, and definitely a good value given that one of the mics is 90 times more expensive than the other.
Others in the thread agree. Five years after posting the thread on GroupDIY the creator of the mod, kingkorg, noted that, despite having access to genuine Neumanns, the friends he gave the modded Perception to still return to it year after year.
