Banzai's KM84 DIY Body & PCB kit build thread

[JW]

The capsule or the whole mic?

 

[Aleguitarpro]

Would anyone have a Maiku sdc for sale? I'm thinking perhaps someone who opted for a 3u capsule may want to unload their Maiku?
Already posted in Black Market.

If you are interested in my mics (you can listen them in comparison with original km84) a couple of post before yours.
Let me know. I can sell them in couple (completed)

 

[fsalter]

The capsule or the whole mic?

Just the capsule

 

[gearfreq]

Hey Banzai! Anymore KM84 kits available? Thanks

 

[FarisElek]

I put an NOS TI 2n3819 in this build and It's awesome . Definitely recommend finding a better 3819. Was able to bias it with the original trimmer unlike the central which needed 24.2k . Takes a LOT to make this thing noticably clip now, and it may be in my head but sounds flatter. I also put a 1uf tantalum at C4, and I just ordered a 3u capsule. It's weird how much i need to EQ high mids on my acoustic guitar with the current capsule. I'm not necessarily saying the Maiku capsule is bad, I'm just personally not in love with how it sounds in the high mids.

 

[JMan]

Wow, where did you manage to get ahold of that?

I'm planning to try out the 3U capsule, and I was thinking of swapping out the FET at the same time.

 

[FarisElek]

I got lucky and found 2 for sale in Indiana. They were in the original matchbox style packaging.

 

[TwentyTrees]

...Definitely recommend finding a better 3819...

I'm using 2N3819s in a few upcoming projects (including my KM84 kits), so I took a bit of time earlier this week to measure IDSS and Vgs(off) of the 41 I have around. The results were interesting:

Fairchild (9, with 4 from an earlier run of these kits)

• IDSS range: 2.4 to 6.7mA (mean 4.17mA)
• Vgs(off): 1.3 to 2.5V (mean 1.78V)

Motorola (30)

• IDSS: 3.4 to 9.2mA (mean 5.7mA)
• Vgs(off): 1.4 to 2.4V (mean 1.88V)

Central (2, both from a later run of these kits)

• IDSS: 18.4mA, 20.7mA
• Vgs(off): 4.6V, 5.6V

Obviously my sample sizes are quite different, and in the case of the Central FETs I only had two to test, but the fact that they both tested so far outside the IDSS and Vgs(off) ranges of both Motorola and Fairchild seems relevant given several folks' experience with the Centrals in this thread. As it is, I'll be using pairs from Motorola with matched IDSS in the 5.2 to 5.4mA range for consistency - I note @Matador suggested IDSS of 0.5 to 2mA, though none of mine tested that low!

FWIW I used the "simplified test setup" from Trevor's Repair Café, here: Measuring JFET Idss and Vgs(off)

 

[mickdundee63]

Anyone used both the warm audio and 3u capsules and have an opinion on respective strengths?

 

[Ricardus]

As it is, I'll be using pairs from Motorola with matched IDSS in the 5.2 to 5.4mA range for consistency - I note @Matador suggested IDSS of 0.5 to 2mA, though none of mine tested that low!

I bought 60 NOS Motorolas and everyone that I've use and tested has measured right around 5.3 Like dozens of them are consistently around that number.

And of all the dozens of NOS 3819's I've bought in the last 4 years, I've only found two of them in the 2's and they were vintage Fairchilds.

 

[FarisElek]

Anyone used both the warm audio and 3u capsules and have an opinion on respective strengths?

Well as far as I can tell you can only buy the Warm capsule in omni.

 

[craigmorris74]

Anyone used both the warm audio and 3u capsules and have an opinion on respective strengths?

I like the Warm Omni.

 

[FarisElek]

What effect does using a omni kk83 type capsule on a vented body like the banzai project? Is it even omni anymore?

Ryan

 

[craigmorris74]

Here a k83.

 

[RuudNL]

Anyone used both the warm audio and 3u capsules and have an opinion on respective strengths?

I have a pair of 3U cardioids and they sound (and measure) excellent.
No strange peaks and/or dips and they are very affordable.
A big improvement compared to the capsules that came with the kits.

 

[FarisElek]

Amazing. I'm excited to get mine in the mail anytime now. Curious if anyones considered building a clone a km84 circuit and using a LDC capsule, maybe something like soliloqueen's flat 47, or even a one sided k47 mounted in a big ole flashlight shaped body? perhaps get a closer response to the kk84? You wouldn't get the benefits of using a SDC obviously but maybe it would be similar? Kind of a cooky idea but might be fun.

Ryan

 

[doqmemory]

Amazing. I'm excited to get mine in the mail anytime now. Curious if anyones considered building a clone a km84 circuit and using a LDC capsule, maybe something like soliloqueen's flat 47, or even a one sided k47 mounted in a big ole flashlight shaped body? perhaps get a closer response to the kk84? You wouldn't get the benefits of using a SDC obviously but maybe it would be similar? Kind of a cooky idea but might be fun.

Ryan

See this project: FET847 Microphone Project Circuit By Jonathan Burtner PCB Layout By Poctop

 

[FarisElek]

Dang! There it is! Makes sense

See this project: FET847 Microphone Project Circuit By Jonathan Burtner PCB Layout By Poctop

 

[McIrish]

I have a pair of 3U cardioids and they sound (and measure) excellent.
No strange peaks and/or dips and they are very affordable.
A big improvement compared to the capsules that came with the kits.

Which specific capsule did you get? I really need to do something with these mics but I dislike the Maiku capsules. The off-axis is very boomy and odd. I'd buy a couple 3U capsules if I could find ones that fit and sounded better. What I'd really like would be a way to use an Oktava MK-012 cardioid capsule on this mic body. That would be fantastic, but the threads are way too different and would need some type of adapter.

 

[JMan]

Which specific capsule did you get? I really need to do something with these mics but I dislike the Maiku capsules. The off-axis is very boomy and odd. I'd buy a couple 3U capsules if I could find ones that fit and sounded better. What I'd really like would be a way to use an Oktava MK-012 cardioid capsule on this mic body. That would be fantastic, but the threads are way too different and would need some type of adapter.

I don’t want to speak for RuudNL, but I just ordered a matched pair of 3U cardioid SDC capsules. I’m excited to try them out (they haven’t arrived just yet). The Series mm5 appears to be the right fit for this kit.