How long is a piece of string?
Spoilers - depends directly on what bias voltage you apply to it, and then the gain of the circuitry after it.
Soliloqueen's k87(k67) and k47 capsules
- Thread starter kingkorg
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Help Support GroupDIY Audio Forum:
How long is a piece of string?
Spoilers - depends directly on what bias voltage you apply to it, and then the gain of the circuitry after it.
I had this discussion with @kingkorg @soliloqueen @Khron and others when the Arienne K87 capsule went to version 2.0 when the gold surface diameter of the diaphragm was reduced. We then tried to evaluate the influence of the voltage drop provided by the capsule against the reduction of the capsule capacity.
You just have to read the previous posts in this thread.
You will find out extremely interesting things.
soapfoot
Well-known member
I'm told my historic K47 (cardioid) has landed!
I'm out of the country for a bit so won't be able to put a mic together immediately, but I'm very excited this has come available
Was super impressed with the quality of the 1st gen flat K47 and it seems things have only gotten better
Cheers!
I'm out of the country for a bit so won't be able to put a mic together immediately, but I'm very excited this has come available
Was super impressed with the quality of the 1st gen flat K47 and it seems things have only gotten better
Cheers!
Excellent! What are you planning to build, a U47fet or something else? I think that the tolerances are tight enough that the results can be decent in other topology as well.
No, they aren't. If they were tight enough to be used for other patterns they would be a higher bin
soapfoot
Well-known member
47FET, Moby transformer
Yes, it makes sense. You have also specified this aspect in other posts.
But our pleasure is to experiment, regardless of the predictability of the results.
We thank you again for transparency and honesty, for everything.
Definitely a winning combination!
klem
Well-known member
Could you share where you are with the spacer issue? Does this apply to all capsules or just the 87s?
Same for finding the slight bass drop issue in the k87s?
Now that K47 is up, how does it compare to Flat47 in terms of SPL handling?
Finally, can you share capacitance of each capsule, and any 'ideal' operating ranges in terms of V or mA?
It turned out to be the diaphragm tension differing due to inconsistencies in the inner diameter of the jigs that I hadn't accounted for and no not really because the k47 doesn't care as much about this as the k87 because of its different pressure and proximity response. The accurate k47 is 2dB hotter than the flat k47. Both of them can handle pretty high SPL. They should operate fine up to about 75 volts. Both the accurate and flat k47s have 70pf capacitance, the same as my reference vintage k47s. The k87 v2, since it's based on an early 60s k67, has a very low capacitance of about 52pf. The sensitivity of the k87v2 is extremely low. It's a little over half as loud as the V1. That's period correct, the V1 was much too loud, so oh well.
Rob Flinn
Well-known member
Any news on when the K87V2 are shipping please ?
pretty sure we've fixed our issue, waiting on confirmation from third party testers. After that, we'll go right back into production. At this rate, we might just do a run of 500 of them. Soonest delivery date is ~35 days for non-prioritized orders. Probably looking at more like 45 or 50 days. At the very least, things are actually moving again this time. I might swap the production dates on some of these runs if I can get away with it to get retail customers their orders a bit faster.
Last edited:
GhostlyStudio
Member
- Joined
- Jun 19, 2024
- Messages
- 18
Are the K47's shipped in batches @soliloqueen ?
almost every k47 is shipped right now except for the ones with utm transformers since i'm waiting on a stock transfer
shoetique
Member
Just preordered a K87V2. Looking forward to the final product!
all k47 orders are shipped. there is currently no wait time for any k47 or flat k47 order. still waiting for final word on the k87, but things are looking good. i hope people post some audio samples and stuff of the new one!
klem
Well-known member
got capsules the other day wayyy sooner than i anticipated! moving at a leisurely pace on these builds but once finished happy to post some bass guitar samples of F47 and K47 in 47FETs or 847s. BTW, I noticed "white" or "red" on capsules, is that in reference to your sorting process? thanks again, each one is a thing of beauty!
That's the front side on a 47fet capsule
finally got around to adding a full set of shipping options for us customers so it isn't just first class mail
untamedfrontier
Active member
@solilioqueen are the cardioid capsules single sided, or just not as tightly matched? Basically I'm just curious if a cardioid only could be used in figure 8, just with different characteristics based on side or if they are as written and only able to be used in cardioid
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