Soliloqueen's k87(k67) and k47 capsules

[dmp]

SWT7 may no longer be an option. I'm not sure Thiersch is still operating. I've had an order pending with them since last October and no longer get responses by email.
A blue PVC Thiersch is my favorite capsule in a U47 build. How can I get close to this?
Soliloqueen, any thought about doing a PVC capsule? Or is the diaphragm material not the determining factor? I did not like the Red Mylar Thiersch.
Either the flat 47 or the 1:1 47? (when is the 1:1 47 coming out?)

 

[soliloqueen]

Soliloqueen, any thought about doing a PVC capsule?

Not at this time, nor an M7. The gluing is annoying, frankly. Maybe later on.

I did not like the Red Mylar Thiersch.

I do, personally, find the 3u to be better than the thiersch red. there's a reason so many builders are moving to it in the shortage. it genuinely is a pretty exceptional capsule.

(when is the 1:1 47 coming out?)

the 1:1 k47 is second on my to-do list after another project, so I am not sure. I'll keep everyone as up to date as I can.

 

[Ricardus]

What's about Dany's D7 capsule? Anyone used it?

 

[soapfoot]

the 1:1 k47 is second on my to-do list after another project, so I am not sure. I'll keep everyone as up to date as I can.

Eagerly awaiting this, too. I think it'd be perfect for a U47FET, which is next on my to-build list.

Are you willing to share what your next project is?

 

[dmp]

I do, personally, find the 3u to be better than the thiersch red. there's a reason so many builders are moving to it in the shortage. it genuinely is a pretty exceptional capsule.

I just want to clarify, I wasn't saying I thought the blue was "better" than the red. They are different and I liked the blue better in my EF800 DIY u47 build.
I also compared the red to a early groupbuy k47 from Maiku and liked the Maiku better.
Anyway, just ordered a pair of flat k47s - excited to hear in M49s & U47s I have ready

 

[kingkorg]

Or is the diaphragm material not the determining factor?

Fwiw my 2c, as long as the capsules are matched and tuned identically to sound identically (which is very difficult) there shouldn't be any difference between pvc and mylar. I believe the any difference comes from the production variations. However as mylar and pvc age way differently, they will diverge considerably over time.

 

[soliloqueen]

Fwiw my 2c, as long as the capsules are matched and tuned identically (which is very difficult) there shouldn't be any difference between pvc and mylar. I believe the any difference comes from the production variations. However as mylar and pvc age way differently, they will diverge considerably over time.

i have heard that the structure of PET is anisotropic and the structure of PVC is isotropic. some people claim that means it's best to tune it with greater tension in the direction of differing stiffness or else it will sound different than PVC, but I don't have the materials experience to confirm or refute this yet.

 

[soliloqueen]

I just want to clarify, I wasn't saying I thought the blue was "better" than the red. They are different and I liked the blue better in my EF800 DIY u47 build.
I also compared the red to a early groupbuy k47 from Maiku and liked the Maiku better.
Anyway, just ordered a pair of flat k47s - excited to hear in M49s & U47s I have ready

Thanks for the order! Curious to know what you think. I'm taking notes on how I want to tune the accurate-backplate k47 based on hearing the flat k47 on different sources. The flat k47 is a pretty airy capsule as a result of its tuning, not because it has more air than usual, but no mids bump in contrast. I think it does a better job as an m7 alternative than a k47 personally. I'm going to try to balance the next model like some of the better first-party k47s I've heard, where it's up 2-3dB in the 4-5k area but not the 4-5dB of some of the u47 fet capsules where it starts to sound a bit "telephone effecty". First party k47s are a bit of a mixed bag, IMO. Some of them sound...brittle? But when they're good, they're really good.

 

[kingkorg]

i have heard that the structure of PET is anisotropic and the structure of PVC is isotropic. some people claim that means it's best to tune it with greater tension in the direction of differing stiffness or else it will sound different than PVC, but I don't have the materials experience to confirm or refute this yet.

Sorry, you are right, i actually meant as long as they are tuned to sound the same.

 

[Recording Engineer]

What's about Dany's D7 capsule? Anyone used it?

I have a pair in a pair of mics with a Western Electric 396A and a Lundahl LL1940; a design Chris Prucher (Barbaric Amplification) and I collaborated on and he built for me. As is, they’re definitely their own thing with an emphasis of a big, smooth, whole-broad-range of mids. I have noticed that getting close to it can have some very heavy-proximity effect and at least a foot away - balances the whole thing out. Absolutely zero sibilance-issues at any time, even if you eq to brighten-up as much as you want.

Used in traditional-circuits, I have no experience.

 

[soliloqueen]

i'm getting reports of an uncommon issue where the k87 can start to leak between the backplates and lose figure 8 in u87i circuits if the capsule takes a hard enough blow to the side. This shouldn't happen during normal use, but shipping is shipping... If yours has this issue, replacement is free. It was my fault this was overlooked, not my assembly team's. I made the decision not to sleeve the screws because I hadn't personally run into the issue, and I failed to properly increase the hole size to account for removing the sleeve. The issue is rare, but I'm annoyed enough at my own mistake that we will probably be reassembling all the current capsule stock rather than waiting for batch 2.

If you are making a u67 or using the capsule for any other purpose, you can safely disregard this post. this problem affects people building u87s only. If they test isolated, you're still good to go. These capsules also have a lifetime warranty for manufacturing defects, so if your capsules are isolated now, but the mic takes a fall and you encounter this problem in a few years, replacement will still be free at that point.

Intrepid users can separate and rejoin the two halves to solve this problem. I will still honor warranty replacements if you do this and mess something up, since it's still my fault.

 

[kingkorg]

Also for the people obsessed with the builds that require isolated backplates, there is a reason Neumann moved away from this design. The two isolated backplates forms a fixed value capacitor of relatively large value that negatively affect the performance increasing the noise and thd. Of course if you connect the two halves and use the capsule in a design that doesn't require isolated backplates you don't get this issue.

 

[Tim Campbell]

Also for the people obsessed with the builds that require isolated backplates, there is a reason Neumann moved away from this design. The two isolated backplates forms a fixed value capacitor of relatively large value that negatively affect the performance increasing the noise and thd. Of course if you connect the two halves and use the capsule in a design that doesn't require isolated backplates you don't get this issue.

kingkorg what do you consider a large value? Between backplates there is usually only a value of 50 -60pf. I haven't measured it with any precision but I haven't found any noticeble increase in capsule noise in a 251 build compared to a C12 build

 

[soliloqueen]

kingkorg what do you consider a large value? Between backplates there is usually only a value of 50 -60pf. I haven't measured it with any precision but I haven't found any noticeble increase in capsule noise in a 251 build compared to a C12 build

can you double check that on a k87? i've got ~200pf on the few k87s I've tested. 210 and 220pf on 2 first party ones and 199pf on a boutique.

 

[Tim Campbell]

can you double check that on a k87? i've got ~200pf on the few k87s I've tested. 210 and 220pf on 2 first party ones and 199pf on a boutique.

Me bad. I don't build K87's these days and I forgot that when I measure this value I have to switch the range on my meter so I wasn't converting. You are right. The Neuman capsules are higher capacitance. Those values sound right.

 

[kingkorg]

kingkorg what do you consider a large value? Between backplates there is usually only a value of 50 -60pf. I haven't measured it with any precision but I haven't found any noticeble increase in capsule noise in a 251 build compared to a C12 build

I haven't measured CK12, but if we nitpick about couple of pf here and there of fet/tube parasitic capacitance 50-60pf isn't something to ignore.

Take a look at Uwe Sattler reply #4. TLDR isolated backplate arangement k87 has 8.4db less sensitivity.

https://repforums.prosoundweb.com/index.php/topic,36194.msg531542.html#msg531542
Important notice to people not clear over what we are talking about here. This is not an issue of any particular capsule, it's about circuit input topology and how the capsule is used in a circuit.

 

[Tim Campbell]

Great link. Yes I shouldn't come in in the middle of a discussion. From just reading your post it was easy to think you were saying that the capsule was noisier.I will examine this next time I get the chance.

From building split backplate capsules for many years I lean more towards the idea that companies moved away from split backplates designs simply because they fail more often than bridged backplates and companies do not want to deal with failing products.

 

[GeorgeToledo]

SWT7 may no longer be an option. I'm not sure Thiersch is still operating. I've had an order pending with them since last October and no longer get responses by email.
A blue PVC Thiersch is my favorite capsule in a U47 build. How can I get close to this?
Soliloqueen, any thought about doing a PVC capsule? Or is the diaphragm material not the determining factor? I did not like the Red Mylar Thiersch.
Either the flat 47 or the 1:1 47? (when is the 1:1 47 coming out?)

I have an SWT7 and a Neumann k47 in two mics with matching electronics.

My opinion is that the SWT7 has likely not been praised highly enough because of it having been used in some mics that have lower grade electronics than the k47 they are compared against. People aren’t exacting enough with the comparisons. I haven’t heard any other product as close to a real k47 as a SWT7 redline, and I’ve heard a lot of them. (None from Ari though!)

 

[soliloqueen]

I have an SWT7 and a Neumann k47 in two mics with matching electronics.

My opinion is that the SWT7 has likely not been praised highly enough because of it having been used in some mics that have lower grade electronics than the k47 they are compared against. People aren’t exacting enough with the comparisons. I haven’t heard any other product as close to a real k47 as a SWT7 redline, and I’ve heard a lot of them. (None from Ari though!)

the k47 is very purpose built. it has a specific sound and works with specific setups. I also suspect different neumann k47s are tuned quite differently, maybe on purpose. I have heard neumann k47s with and without large presence peaks and it's big enough that I wonder if there are 2 different variations of the capsule.

 

[elskardio]

Also for the people obsessed with the builds that require isolated backplates, there is a reason Neumann moved away from this design. The two isolated backplates forms a fixed value capacitor of relatively large value that negatively affect the performance increasing the noise and thd. Of course if you connect the two halves and use the capsule in a design that doesn't require isolated backplates you don't get this issue.

Interesting. How much of a noise difference are we talking here?
Is it something noticeable by ear?