AKG C214

Any information available about the AKG C214? (Schematic?)

Some googling revealed this, in case it helps:

http://www.saturn-sound.com/images%20-%20microphones/akg%20c214%20-%20pcb.jpg

http://www.saturn-sound.com/images%20-%20microphones/akg%20c214%20-%20capsule.jpg

Yes, that's what I found already!
But unfortunately no schematic on the internet.
(There is a 'service manual', but that only contains some mechanical parts and the assembled PCB...)

You have one in your hands that needs work? Or just curious about the circuit?

I am getting one in from a friend that doesn't work, that why.
Maybe the circuit is similar to another AKG microphone?
It uses an electret capsule, not an externally polarized capsule, so that would make the circuit less complicated I could imagine.
(I am not a real fan of SMD technology, when it comes to repairs...)

I don't know about similarities, but assuming there's no circuitry on the back side of the PCB, it can't be totally impossible (or unfeasible) to trace the circuit. Looks a helluva lot simpler than the KSM27 / KSM141 circuits i lifted, a year or two ago

It's little bit different than C2000/C3000/4000, but still  i would look for similarities.
cloud.akg.com/7771/c4000_b_service.pdf

Khron said:

...it can't be totally impossible (or unfeasible) to trace the circuit.

Click to expand...

Yes, of course you are right! But: why re-invent the wheel if somebody else did this before, or if there is a schematic somewhere hidden online!
I am getting the microphone here next week, and then we will see!

And thanks ln76d for the suggestion, maybe there are similarities.

RuudNL said:

And thanks ln76d for the suggestion, maybe there are similarities.

Click to expand...

Capsule is the same

Any ideas for improve it?

Just wondering how you got on with the C214 in the end Ruud ,
I see them going cheap on the second hand market now for less that 200 euros ,
Looks like a halfway decent edge terminated ,singled sided capsule .
plonk that into something like a Solidtube body and with minor modifications youd have something very close to a C12 VR on cardioid .

The repair was extremely simple, one of the (thin) capsule wires was broken!

Whats your view on the quality and sound of these AKG capsules ?
Is it a step up from the china made edge terminated units ?

It is too long ago to remember how the microphone sounded.
It worked again, so I returned it to the owner!
(In general, I am not a fan of electret capsules, but maybe that is my bias...)

RuudNL said:

(In general, I am not a fan of electret capsules, but maybe that is my bias...)

Click to expand...

I see what you did there, even if unintentionally...

@RuudNL, how much bias can you take before collapsing?

@Khron, taking it a step further.

Im probably not too much of a fan of electret mics either .
Below is a pic of the C214, a C414 XLII and a ck12 I see the very fine wires and also it seems the capsule itself is on an elasticated mount . As far as I can tell AKG do claim the 214 is a true LDC mic based on similar capsules to other famous mics they make . I havent found a pic of the inside of a P420 but it looks like that has the usual china made capsule.
Theres some good info here about the Ck12 teflon and other capsules , including detailed drawings of the internal parts .
http://www.saturn-sound.com/Curio's/akg's 2072 z 0009 capsule.htmAdded a photo of the p series capsule .

It is electret. Which doesn't mean it's not a true LDC. Akg claims there is no difference between the two approaches besides noise floor. I haven't found any aspect that makes electrets inherently worse. There is one theoretical downside to electrets, but measuring it would be a nightmare.

To perform this test you would need to have the exact same capsule tested with and without electret material and do some tedious testing. Which is doable, but i doubt anyone would actually do it.

Thanks for the link Khron ,
I may be wrong but the C214 capsule looks indentical to the C414XLII , including the indent on the ring and the red dot , obviously C214 only needs a single sided gold membrane as its cardioid only .

I would also be interested in the circuit diagram of the C214, because I find the fixed low-cut of 60 Hz and the much too high low-cut of 160 Hz unattractive. Probably the fixed low-cut could be removed and the switchable low-cut could be lowered to 80 Hz by changing only two capacitors.

Without knowing the schematic, I would guess that doubling these two capacitors would do exactly what I intended: