Like any microphone the performance of the DPA 4099 is somewhat dependent on the quality of the mic pre that it goes through. I recently acquired a John Hardy M-1 mic preamp and after recording with my 4099 through the John Hardy I found myself wondering if the mic was performing optimally. It sounded good but the sound wasn't as solid as I would have liked.
I decided to call DPA service at their US headquarters in Colorado. I spoke with Jed and he asked me to send my mic to him for evaluation. Wthin a day of receiving my mic Jed got back to me. It turned out that with some preamps my mic failed to power up completely. Two days later I received a brand new replacement for my 4099. Does it sound better? You bet it does! The defective mic I had before sounded pretty good but now the sound is all there. The bass has more weight to it. The output is higher so I need less gain from my preamp. The air and sparkle is there without any eq boost needed.
I've seen a few forum discussions where players are questioning whether the mic is worth the retail price of $600. When I consider the incredibly fast and thorough customer support I received, I have to say that it's worth every penny. When you are gigging accidents happen and gear sometimes needs service. In my experience customer service is one of the most important considerations when buying pro gear. DPA came through for me with flying colors.
A reader asked me whether there is any audible self-noise with my DPA 4099. I fingerpick with the pads of my fingers and my fingernails so it's safe to say that my playing volume is on the soft side of the volume range. With my Hardy M-1 which is extremely revealing there is no self-noise from the mic at all. Furthermore the sound quality rivals the best acoustic guitar recordings in my music collection. I wouldn't be surprised to see James Taylor or Paul Simon using a DPA 4099 on stage or even in the studio.
With my Fishman SoloAmp and Martin OOO-18GE 1937 the DPA 4099 works beautifully. You just can't get this quality of sound from a guitar pickup or from a mic inside a guitar. The phase reverse switch on my SoloAmp eliminated a feedback loop with the top of the guitar and I could play without fear of the dreaded wolf tone. For me it's a big plus that I don't have to drill or modify my guitar in any way to use the DPA mic. And if I want to play my 1963 Gibson LG1 it only takes a minute to switch the mic over to that guitar.
For the singer/songwriter with a project studio the DPA 4099 Guitar microphone is no brainer. It's sound when paired with a good preamp is natural and uncolored with superb dynamics and plenty of detail. You would be hard pressed to find a better mic for recording your acoustic guitar. When you consider that you can carry it in your guitar case accessory compartment and use it for live gigs it certainly earns it's keep. For half the price of a used KM84 (if you can find one) you are getting a first rate recording mic and an excellent acoustic guitar pickup for use on-stage.