A while back @soliloqueen asked me if i was willing to measure a prototype of k47 she makes. I shared some measurements of this capsule before. And now two k87 (k67 with isolated backplates) arrived for testing.
Disclaimer: I'm not making money by building/repairing/measuring mics. Occasionally i sell some I don't need, and that's it. I have a job not related to mics. I'm passionate about debunking misconceptions surrounding gear, I'm all about things that really matter, saving time, money, and energy of DIYers who want to get results quickly and not get ripped off by snake oil pushers.
That being said, i don't know who Soliloqueen is, besides her real name (which I will not share in PM). I do not know the specifics of the manufacturing process, or if the pre-production capsules I tested will be the same as the production models. No idea what the resale price will be. Even though she never asked for it, I paid for the k47 she sent me, and will pay for the k87 as soon as I find use for them. I just have way too many capsules of this type right now, and I'm personally not crazy about u87/u67 mics.
Sorry for the long intro.
K67 TLDR version of the "review" is that the capsule matches the performance of the original Neumann capsule I compared it to in every aspect. So yes, I absolutely recommend them. The measurement of one of the capsules front vs back.
This is the second one, slightly larger difference, in my book irrelevant and inaudible. as long as the shape is the same.
As I am empirically driven person I share the testing results, so you can decide for yourself. The two capsules I received are very close in performance (1db peak to peak difference here and there), and can be used as matched pair even though they hadn't been previously matched. So the manufacturing tolerances are really tight. Front to back the responses are basically identical on both of them. No crazy dips, peaks anywhere. The shape and amplitude of HF response is spot on.
Keep in mind Neumann has higher tolerances than this, which can be seen in their u87 manufacturing video. Capsules also age, so if you make a clone using this capsule and shoot it out against some random Neumann k67 based mic and don't get 100% identical results don't blame it on this capsule.
Obviously to nail the u87/u67 sound you also need precisely tuned deemphasis network, bias, mechanics and pattern polarization solution that will retain the perfect front to back balance of the capsule.
Here is this capsule against one of my k67 favorites from 797 audio which also nails the shape but is too bright, and doesn't have isolated backplates.
And this is the capsule in circuit which is tuned to perform in every aspect as the original u87. Disregard the 150hz peak, it's a measurement artefact, and also serves as a reminder the graphs I publish are NOT SMOOTHED!
As for the k47 the situation is slightly different simply because there is no one right response of the k47. They vary a lot, even Neumann ones. Soliloqueen's is different than any other k47 replica i tested because it is smoothest, and closest to M7 response. Every k47 i tested until now has a bump in 5K range which i don't like. Some of the Neumann's have this as well but not all of them.
As the goal of George Neumann, according to the patents, manufacturing documents, and Sigmund Thiersch, was to make M7/k47 as flat as possible, I like them exactly this way. Soliloqueen's k47 nails it. Of course you will get some wiggling in the response once you put the capsule in a body.
Once again the response front to back is 100% matched. This capsule ended up in my favorite k47 based mic. I have one more that uses Dale's M7 which is another story. Disregard the 50hz difference, again measurement artefact simply because the capsules are not shielded - no grille. Both sides are flat down to 50hz and below.
Here's how the k87 looks.
Update August 2023:
Soliloqueen sent me 2 original Neumann capsules and two of her k87. All four capsules and all their sides measure exactly the same. Here's her k87 vs Neumann k87.
Disclaimer: I'm not making money by building/repairing/measuring mics. Occasionally i sell some I don't need, and that's it. I have a job not related to mics. I'm passionate about debunking misconceptions surrounding gear, I'm all about things that really matter, saving time, money, and energy of DIYers who want to get results quickly and not get ripped off by snake oil pushers.
That being said, i don't know who Soliloqueen is, besides her real name (which I will not share in PM). I do not know the specifics of the manufacturing process, or if the pre-production capsules I tested will be the same as the production models. No idea what the resale price will be. Even though she never asked for it, I paid for the k47 she sent me, and will pay for the k87 as soon as I find use for them. I just have way too many capsules of this type right now, and I'm personally not crazy about u87/u67 mics.
Sorry for the long intro.
K67 TLDR version of the "review" is that the capsule matches the performance of the original Neumann capsule I compared it to in every aspect. So yes, I absolutely recommend them. The measurement of one of the capsules front vs back.
This is the second one, slightly larger difference, in my book irrelevant and inaudible. as long as the shape is the same.
As I am empirically driven person I share the testing results, so you can decide for yourself. The two capsules I received are very close in performance (1db peak to peak difference here and there), and can be used as matched pair even though they hadn't been previously matched. So the manufacturing tolerances are really tight. Front to back the responses are basically identical on both of them. No crazy dips, peaks anywhere. The shape and amplitude of HF response is spot on.
Keep in mind Neumann has higher tolerances than this, which can be seen in their u87 manufacturing video. Capsules also age, so if you make a clone using this capsule and shoot it out against some random Neumann k67 based mic and don't get 100% identical results don't blame it on this capsule.
Obviously to nail the u87/u67 sound you also need precisely tuned deemphasis network, bias, mechanics and pattern polarization solution that will retain the perfect front to back balance of the capsule.
Here is this capsule against one of my k67 favorites from 797 audio which also nails the shape but is too bright, and doesn't have isolated backplates.
And this is the capsule in circuit which is tuned to perform in every aspect as the original u87. Disregard the 150hz peak, it's a measurement artefact, and also serves as a reminder the graphs I publish are NOT SMOOTHED!
As for the k47 the situation is slightly different simply because there is no one right response of the k47. They vary a lot, even Neumann ones. Soliloqueen's is different than any other k47 replica i tested because it is smoothest, and closest to M7 response. Every k47 i tested until now has a bump in 5K range which i don't like. Some of the Neumann's have this as well but not all of them.
As the goal of George Neumann, according to the patents, manufacturing documents, and Sigmund Thiersch, was to make M7/k47 as flat as possible, I like them exactly this way. Soliloqueen's k47 nails it. Of course you will get some wiggling in the response once you put the capsule in a body.
Once again the response front to back is 100% matched. This capsule ended up in my favorite k47 based mic. I have one more that uses Dale's M7 which is another story. Disregard the 50hz difference, again measurement artefact simply because the capsules are not shielded - no grille. Both sides are flat down to 50hz and below.
Here's how the k87 looks.
Update August 2023:
Soliloqueen sent me 2 original Neumann capsules and two of her k87. All four capsules and all their sides measure exactly the same. Here's her k87 vs Neumann k87.
Last edited:
