C414 EB P48 build

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I've actually got a couple of spare capsules and I'm going to attempt to put in a shim to isolate the backplates, it may or may not work!!!
Will also try out this new switch idea with the two small switches soldered together and put on a pcb.
I've also just got some J113 which I'll try with the J201 and also the 2N5458 and see how they pan out.
I've taken all components off this pcb and populated another, will change all caps and see if I can get a good output out of this 3rd version.
If I can crack these last bits I can then build some bodies to house this all and have the switches in a nice place.
 
You seem to be changing too many things at one time

First thing I would do is buy/build a test setup for the JFETs you have.
If they are from online non-electrics places IMO you will need to check what you bought.
Check this forum and the web for testers

Check IDSS
Vgs at operating currents
It is more involved to test the input capacitance.

Once you do that build circuit test fragments to check the parts.

In one of the thread I posted a link to possible switches

The original AKG is well designed and JFETs that are tested out of circuit and selected should drop in and work.

Think/understand drain currents at at different Vgs

read what myself and others posted in the 414 like threads at this forum
 
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yep i know ive got a lot to understand, build and test to get this right.

it just seems really weird that i have two mics which have loads of output and all voltages test well and i have one where ive changed every component and capsule and cant get the same output from it?
 
also, strangely when the low output mic is put through one of my Neve 1073 mic preamps and put on guitar it sounds wonderful!! and there is plenty of output!!!
i did notice that on pin 2 on the low output mic it was 48.2v and on pin 3 it was 43.2v through the mackie desk which im powering it by when testing, dont know if this is correct or not? i thought it would be 48v on both pins not have one 48v and the other 5v down?
 
Maybe the simplest solution is the most obvious!!
I've got step down 2:1 txf in this low output version, maybe in the other two it's step up!!?
I thought I did check this but will take another look just in case.
The J113 seems to work well along with the J201.
 
Dodgy choke was the problem on one side!!!
Ended up changing the xlr connector and replacing everything for it to be a dodgy choke!!!
All sorted now and have tweaked so T3 is getting 0.45ma and T1 is 0.35ma
 
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this is a little test ive been doing, the drums are through the C414 1st version i made with a API 2500 smashing it a fair bit.
Bass is DI with a tiny bit of API love.
The first two guitars where the 3rd C414 when it wasnt very well, the 2nd two guitars are before i had fully fixed it and the guitars lack bottom end and sound shrill, the 3rd pair of guitars i think sound great, and this is the C414 setup and working correctly.
Each guitar has been recorded on its own and double tracked.

 
I forgot pretty much everything over 'rona. Would a Maiku CK12 be good in a C414 style build, or is it the same as the typical Chinese RK12? Thinking about building a C414 style mic that gets in that ballpark. Maybe something a little less bright than my CAD M179s.

I guess the short version is: Which sub $150 (maybe $200) capsule perdorms best for a budget C414EB clone?
 
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this is a little test ive been doing, the drums are through the C414 1st version i made with a API 2500 smashing it a fair bit.
Bass is DI with a tiny bit of API love.
The first two guitars where the 3rd C414 when it wasnt very well, the 2nd two guitars are before i had fully fixed it and the guitars lack bottom end and sound shrill, the 3rd pair of guitars i think sound great, and this is the C414 setup and working correctly.
Each guitar has been recorded on its own and double tracked.


Wow, what capsuIe was in the drums one? Sounds great. No ugIy. AII sounds good!
 
I forgot pretty much everything over 'rona. Would a Maiku CK12 be good in a C414 style build, or is it the same as the typical Chinese RK12? Thinking about building a C414 style mic that gets in that ballpark. Maybe something a little less bright than my CAD M179s.

I guess the short version is: Which sub $150 (maybe $200) capsule perdorms best for a budget C414EB clone?
That Maiku K12, even though its k67 edge terminated, is not bad at all. I would say its a little darker/smoother than the typical Chinese RK12, with a little lift in lows too. Its actually pretty good value, I compared it in pimped alice setup against ck12 teflon in my 414 buls and they sound somewhat similar with the Maiku having a little extra sheen at the top.. I wouldn't say I prefered one against the other, but I rather liked both.
 
There's a C414 clone kit on Mic and Mod I'm looking at. I don't generally like the idea of a kit, but it comes with a C414 style body, a capsule (looks like a typical Chinese "CK12"), and the boards for 500 euros (about $700 my currency). If it goes on sale at any point I may consider it though I don't really like the idea of buying a kit with a Chinese "CK12" capsule because I can't imagine it'll be a big improvement over mics I already have (plus, I don't really want to pay $700 for what could be a $300 build if I source everything myself). They don't sell the body alone, that's what I was really interested in.
That Maiku K12, even though its k67 edge terminated, is not bad at all. I would say its a little darker/smoother than the typical Chinese RK12, with a little lift in lows too. Its actually pretty good value, I compared it in pimped alice setup against ck12 teflon in my 414 buls and they sound somewhat similar with the Maiku having a little extra sheen at the top.. I wouldn't say I prefered one against the other, but I rather liked both.
I don't necessarily dislike the sound of the other Chinese ones, but I can't imagine they're any better than what I already have for cheap all around mics (CAD M179s). I'll look at Maiku again if they are better than the usual ones, but if to get a noticable difference from what's already in my locker requires a $400+ capsule I should probably just wait a bit.
 
This Mic and Mod kit first does not have transformer, so in that regard is not the same as the usually more desired EB or BULS 414.
 
I'll do my best yet again trying to explain why neither Maiku or RK12 won't get you anywhere in c12 or c414 builds.

First of all, asking such a question is exactly the same as: What amplifier can get my Stratocaster to sound like a Les Paul. Answer: No amplifier can achieve that.

The capsule is your guitar, and it's such a shame to waste so much energy into creating wonderfull circuit replicas(amplifiers) with accurate transformers, fets, layouts, bodies, bias points, and in the end use wrong type of guitar.

More or less high end on that RK12 (Maiku, AA, Røde...) type of capsule is determined by the volume of the holes under the diaphragm. It does not mater if you achieve this difference by using EQ or by altering the size of the holes. Paying extra for 2db of HF is paying for turn of the HF knob on an eq. It is the acoustical principle of the capsule that matters regardless of frequency response curve.

By far the best capsule of this type is produced by Rode, and it is found in NT2a, K2, Classic II... it is exquisitely well matched from piece to piece, and front to back. It is not hyped in HF at all, it is almost flat in response. The difference between the Rode models sound comes mostly from headbasket.

However, i've never heard anyone comparing Rode models to c414. So why put this type of capsule in a c414 or c12. In the end you will end up with a Røde mic no matter what circuit you use.

If i were making a c414 inspired mic(and not have CK12) i would try to get my hands on used c4000b, swap the capsule, sell the c4000b with "upgraded" rk12 type capsule and use c4000b for my build. You would need to mod the Akg mic to add polarizing voltage. If you don't need patterns c3000b is great too. Those two mics sound "bad" because of the built in Eq, not because of the capsules. There are also other inexpensive Akg models with similar capsules. The fact they are electrets don't change anything, the material is deposited on the backplate, doesn't affect the performance, and applying pol.voltage to these doesn't change anything.

How to test this without serious testing equipment?

Take Neumann u87 and just about any other mic with 34mm k67. Place them in front of a monitor, at the exact same position, and record pink noise under same exact conditions. Then run EQ Match and match the two recorded files. I promise it will be almost impossible to hear the difference.

Now repeat the same test with two mics that have different construction. Say original c414 and a mic with RK12 equiped capsule. Run the EQ match, and you will get the same exact frequency response while the takes will sound different! You will hear something that many characterize as 3d effect. One will be more 3d.

This is because of how the physical and acoustical principle works and sums 360° of sound into one mono take. The more room in the sound you have the more obvious. This is why i like to test my mics as drum rooms. It's super revealing. Vocals are contrary to what many would think quite poor shootout sources. Low spl, recorded in booths, don't go low, and are relatively poor in harmonics. Slow, and soft transients.

This would be a 1 dimensional, static test. If you start moving the mics around you would see how differently constructed capsules change the 3d response in regards to proximity effect, and off axis response.
 
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