Soliloqueen's k87(k67) and k47 capsules

[soliloqueen]

This thread sure is a wild ride. Who knows what tangent it will go off on next.

@soliloqueen, once the K47, K47F, and K87 are all set, are you still planning on working on some other capsule types, or do you plan on (understandably) holding off for a while to recuperate? If the former, do you know yet (and are you willing to share) what might be on the roadmap?

m7 is next. it's been done for over a year, just wanted to get everything else squared first. I really want to get custom film for it, and have designed a film, but I can't afford to have it made, so I might alter the backplate instead to account for the difference in mass.
model:

 

[soapfoot]

I doubt this is your style, but if you were to try crowdfunding for the start-up costs of the custom film, I'd throw in a few bucks and I bet others would, too.

 

[soliloqueen]

I doubt this is your style, but if you were to try crowdfunding for the start-up costs of the custom film, I'd throw in a few bucks and I bet others would, too.

it would be in the neighborhood of 80 grand to get a custom film made, haha. that's not impossible with production at full swing, but not with our current slowdown.

 

[mrgrooves666]

Hi Ari, when will you restock K87's?

 

[soliloqueen]

Hi Ari, when will you restock K87's?

just finished oem volume and started assembly on the retail batch today actually. was able to find a jig setup that worked consistently with the smaller ring ID. i received quotes from DHL for the price of shipping all of the outstanding orders this morning. I'm hesitant to give dates at this point, but like, less than a month.

 

[cortez07]

m7 is next. it's been done for over a year, just wanted to get everything else squared first. I really want to get custom film for it, and have designed a film, but I can't afford to have it made, so I might alter the backplate instead to account for the difference in mass.
model:
View attachment 135858

How about the K67/K87 cardioid-only?

 

[soliloqueen]

How about the K67/K87 cardioid-only?

might as well throw those in now, actually

 

[soapfoot]

it would be in the neighborhood of 80 grand to get a custom film made, haha. that's not impossible with production at full swing, but not with our current slowdown.

Ah, gotcha

Well maybe an OEM will get excited about a perfect 1:1 and step up to the plate

 

[soliloqueen]

Ah, gotcha

Well maybe an OEM will get excited about a perfect 1:1 and step up to the plate

it's not pvc, it's a custom polyester, and it's only a theory. kind of a hard sell. probably smarter to change the plate.

 

[ElSmurf]

it's not pvc, it's a custom polyester, and it's only a theory.

80k to test out a theory is a pretty big gamble indeed.

 

[Electrobumps]

I really want to get custom film for it, and have designed a film, but I can't afford to have it made, so I might alter the backplate instead to account for the difference in mass.
model:

Out if interest does anyone know what Dan@vintagemicrophoneparts and beeskneez do with their capsules in respect to this?

 

[Roman Beilharz]

people are always surprised at how clinical the flat k47 sounds, at least the shentuo-made versions. i think they're really expecting it to sound like a k47, which it doesn't. i saw someone on RGO describe it as a more mellow ck12, which isn't wrong. i did make an effort to give the new one a bit more color to my taste

i didn't touch the mids or treble at all, but it now begins to roll off above 5k like a regular k47, instead of extending all the way to 20k:
View attachment 135345
View attachment 135346
diff chart between a v1 flat k47 and a few current production. I know some may balk at the loss of extension, but inherently, the k47 design's upper air is not good quality. it's scratchy. it's better rolled off slightly IMO. that's kind of my issue with the k47. the k87, i feel, has too much good-sounding presence, whereas the k47 has a good amount of off-sounding presence. the rolloff in a normal neumann k47 masks the unnatural tone quality of the presence and i think the v1 flat k47 revealed this problem, so i did my best to fix this issue. this is a big reason why i don't really like the m49v reissue. i think that the new tube highlights this issue with the k47 too. m49 clone builds with the same tube could suffer from really scratchy air with the old design, so i made a few tweaks knowing that this configuration would probably be a popular project. the new production flat k47 sounds more like an LDC and less like an SDC. The top end is slightly more refined. We're talking 1.5dB changes here, so nothing huge.

Thank you so much, Arienne, for this insight into the perceived characteristics of the 47's air band. It confirms my own impressions with capsules of similar designs. I did not know, the K47's "scratchy upper air" as you've put it is an inherent design flaw. This was exactly the kind of information I was looking for when chiming into this thread earlier, when kingkorg ruffled my feathers for bringing up the C100 (while he wasn't helping much).

Now I know a little more about what to expect of your K87s, that hopefully will soon arrive for my U67-style pair. And why I am so charmed by the top end of my Thiersch M7.

Being a huge fan of M7s, I can't wait to try out your version of this classic. I am very excited, that you are actually working on this!!

I second the crowdfunding idea, if it could help you to move ahead with it

 

[soliloqueen]

Speak of the devil

 

[Kelvin Zero]

That top capsule looks different to the others?

 

[soliloqueen]

That top capsule looks different to the others?

oh man, this comment threw me for a loop haha, it took me a minute to think about this from the perspective of someone who didn't design the plate. if you mean the hole pattern, the top one is upside-down compared to two below it. the m7 and k47 have holes in concentric circles. blind holes alternate between being drilled on the front and rear. the bottom two are also upside-down, but that's hard to see because of the sunburst from the lathe.

 

[rogs]

On a different subject...... I'm using a flat 47 with one of my current experimental mic circuits, and it sounds really nice...
At present I'm applying a polarisation voltage of 65v across each side of the capsule.... I was wondering if I could safely go any higher ?
I've done a quick search, but I've not yet come across any published recommended maximum (or minimum? ) values for polarising an Arienne Audio
'flat 47'......

 

[soliloqueen]

On a different subject...... I'm using a flat 47 with one of my current experimental mic circuits, and it sounds really nice...
At present I'm applying a polarisation voltage of 65v across each side of the capsule.... I was wondering if I could safely go any higher ?
I've done a quick search, but I've not yet come across any published recommended maximum (or minimum? ) values for polarising an Arienne Audio
'flat 47'......

Which one do you have? I don't know the absolute maximum polarization voltage of the current one. If you have a recent one, you can turn it up until it implodes and let me know if you want. I'll ship you a new one. If not and you have one of the older ones, it should be able to run pretty comfortably at 75 volts. I think I tried 80 and it worked fine too. Potentially 90? The early ones had really low capacitance. The 6um film is also pretty strong.

edit:
you have one of the older ones I think. it should take 75 or 80v and function normally.

 

[rogs]

Which one do you have? I don't know the absolute maximum polarization voltage of the current one. If you have a recent one, you can turn it up until it implodes and let me know if you want. I'll ship you a new one. If not and you have one of the older ones, it should be able to run pretty comfortably at 75 volts. I think I tried 80 and it worked fine too. Potentially 90? The early ones had really low capacitance. The 6um film is also pretty strong.

edit:
you have one of the older ones I think. it should take 75 or 80v and function normally.

Yes, I received mine in April 2023, so quite an early one ..... I think I'll try 75v and see if it makes any significant difference... probably not, I suspect!
Thanks for the reply.

As an aside, you mention that the newer 'flat 47' has a larger capacitance.... what sort of figure are we talking about for these more recent models?.....
Does it affect the sensitivity at all? .....
(What I'm really looking for is a capsule with a larger capcitance and a lower membrane tension, to try with my RF mic experiments! )

 

[kagaboo]

I can't wait for M7 capsule.
I tried K47flat and K47V, they are great!
I hope Ari make K89 capsule...

 

[mrgrooves666]

On a different subject...... I'm using a flat 47 with one of my current experimental mic circuits, and it sounds really nice...
At present I'm applying a polarisation voltage of 65v across each side of the capsule.... I was wondering if I could safely go any higher ?
I've done a quick search, but I've not yet come across any published recommended maximum (or minimum? ) values for polarising an Arienne Audio
'flat 47'......

Rogs I have a pair of your 1st gen OPIC MP with Ari's flat 47, relatively recently supplied, with around 70 volts (R5 , 10R) currently, no issues. 72 Volts to be precise...