AKG 414 EB build

[Spencerleehorton]

HI Guys,

I am starting a build of the AKG 414 EB and wondered a few things:

1. Windings and core details do the 2:1 U35b have?
2. what are the ratio, windings and core details for the U26a?
3. the Dr1 and Dr2 are RF chokes of some kinda, what kind?

any info would be very appreciated, this all may have been covered else where but i have had a good trawl but not come up with anything.

regards

Spence.

 

[Melodeath00]

The Advanced Audio CM414 is supposedly a recreation of the 414EB circuit, and it uses a 2:1 transformer. I do not know exactly how close to the circuit the AA is, or if the transformer is the same, but I thought I'd chime in.

 

[Spencerleehorton]

hi melodeath00,


yeah, i had suspected the 2:1 ratio for the transformer, running up a version of this probably next week once i get all the parts.
more info and stuff soon.

regards

Spence.

 

[Spencerleehorton]

one other thing, where can i get some 4 way and 3 way switches / selectors like the ones on the C414 EB?

regards

Spence.

 

[Winetree]

I have a pair of 414 ebs I got in 1981 with the white ring capsules.
I heard they sound so much better with the brass capsules.
Would a pair of Tim Campbell's capsules be a direct replacement
or would I have to adjust something?

 

[Biasrocks]

Would a pair of Tim Campbell's capsules be a direct replacement
or would I have to adjust something?

Nope, just drop them in. You may want to ask Tim about mounting them in a 414eb, it may require an adaptor.

My EB's came with Brass caps and sound fantastic.

Regards,
Mark

 

[Spencerleehorton]

Hi Guys,

any info on a 4 way mini switch and 3 way mini switches for this build?
I have only so far come up with these:

http://www.ebay.co.uk/itm/10-pcs-Slide-Switch-1P4T-for-signal-control-4-positions-/150473498769?pt=Model_RR_Trains&hash=item2308eb6091

and

http://www.ebay.co.uk/itm/5-Pcs-x-PCB-4-Pin-ON-ON-ON-3-Position-SP3T-1P3T-Mini-Slide-Switch-0-5A-50V-DC-/290913642892?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43bbcde98c

if anyone can chime in with where to get some mini 4 way toggles or lever switches, i've kinda run out of ideas!!!

regards

Spence.

 

[ln76d]

Hi,

i have a lot of microphone parts, but unfortunatelly i don't have 3 and 4 position switches. Only 2 position from later C414.
I think you should check several service manuals from AKG site for switches and the other parts (like the body parts). Why do not use genuine? First look for newer products parts - it's biggest probability, that you will could buy them.
These switches were mounted (if i'm right) in several types of AKG as a reproductions of C414, C12 and probably many more etc.
In each service manual you have an all parts service numbers (newest number is better).
Contact your local AKG distributor service or even AKG Austria, those parts should be cheap.
I have positive experience with AKG Austria. Very good and professional contact.

I repaired and restored C414EB P48 from 70's. Works fabulous.
Original were mounted roederstein tantalum electrolytics, so i put newer roe's. I use newer type Beyschlag/Vishay/Vitrohm metalized resistors, new wima foil caps (same type as original) and what's important - all ceramic caps - C0G/NP0 type. Effect is brilliant Also i repaired teflon capsule.
It's important to remove flux and other **** after soldering - good results with isopropyl alcohol.

If you need some help, just write what you need 

Cheers

Piotr

 

[MicDaddy]

I've an EB-P48 (teflon) in which both membranes of the capsule are sucked into the back-plate.  Would anyone recommend re-skinning the teflon capsules or is this a candidate for a CT12?  The other c12 candidates from my searching are sharing the back-plate, the 414-EB I believe wants it isolated.  Are there other considerations for capsule replacement?

 

[ln76d]

On saturn sound site you have good descriptions with drawings etc. of brass CK12 and all types of teflon CK12.
Both types have double backplates with spacings between.
http://www.saturn-sound.com/Curio%27s/akg%27s_ck12_capsule.htm
If i understand you correctly (or not ), probalby there's no option to reskin brass CK12 with never foil from teflon type.
Teflon capsules have glued diaphragms to the brass rings and to put them out from enclosure without destroing it i's reall hard, but always to do   Those diaphragms have little bit smaller dimensions than the brass one.
Coul you post pics of your capsule, cause i can't imagine how membranes can be suck (or stuck) to the backplates. Maybe we will find solution together

cheers

 

[MicDaddy]

Thanks ln76d for the Saturn link and your thoughts.

From the photo you will find this to be what looks like a nuked or well done diaphragm.

Sorry for not being more clear with my earlier statement.  I was trying to ask which replacement capsule would be suitable for this microphone?  CT12 the obvious choice, are there other ck12 options with isolated backplates?  This is assuming a reskin not possible.

 

[ln76d]

Thanks for the photo!

How about the second side of the capsule, it is in the same state?

If the second diaphragm looks better there will be a few options to repair, but first i need to check it

I have more luck cause i have few of those capsules, but unfortunately i can't share with it.

 

[ln76d]

I think the best way will be buying from AKG a spare capsule for C12 VR (which i belive is the last incarnation of C12).
Solidtube and the many others share very similar capsules (which can be donor of diaphragm if diameter is the same), unfortunately they have completely different mounting system.

http://www.woodbrass.com/images/woodbrass/AKG+C12VR-1.JPG

Sometimes the are on bay:

http://www.ebay.co.uk/itm/AKG-Solidtube-Condenser-Microphone-Replacement-Capsule-/181113502416?pt=US_Pro_Audio_Microphones&hash=item2a2b34bad0

In attachment is the dissasambeled half of the capsule (same half as on your photo). Second side is much more f%^@*d up to open, cause you need to gut all parts inside.

If this is only this side as on photo, you have a luck. You can take the whole half from other capsule.
In case of reskining, some of them are easy to remove diaphragm but in others the diaphragm is stuck.
To check it, try to move around whole diaphragm. Just use diaphragm pin for connector..

 

[Spencerleehorton]

thank you In76d(piotr),

thats great info, i have tracked down the parts:

single pole 4 way switch (1P4T) -  polar pattern (S101, 2148Z0019 Schalter)
single pole 3 way (1P3T) 0 - 10db - 20db - Low Cut Switch ( S01, S02, part no: 2148Z0011 Schalter)

Schalter seems to be the company that made them , i will endeavour to contact them and see if i can get some.
Not really comfortable with getting 100 or so from AKG !!!!!
My aim is to get readily available parts that will work last and obviously are cost effective.
Ive got a CAD design that is exactly the same as the original AKG C414 EB only difference is the switches and the way they are mounted for the moment, until i track down the originals.
Gonna get to working on the circuit next week, should have a prototype by the end of the month i reckon.
Be prepared for me to ask you loads of questions!!!!!

regards

Spence.

 

[ln76d]

Hi Spencer,

unfortunately "Schalter" isn't a company it is the "switch" in german language.

In those quantities it will be problem with AKG

If you didn't tried, try here:

http://uk.farnell.com/jsp/search/browse.jsp?N=203118&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=203118&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D203118%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D203118

Maybe you will not find exactly type but there should be something good enough.
In bigger quantities farnell have good prices, especially if you are not a tax payer.

You can try to ask in AKG Austria, who is the manufacturer of those switches.

Feel free to ask, i hope that i'll be able to help you

 

[ln76d]

In attachement is a newer type switch from another carnation of C414.
Could you send me link to the schematic which you are using?

Look out for the Harman, since AKG now is Harman and the Harman is f&$#@d up, they have probably rights for the design of microphone.

If you will need cheap parts like WIMA, ROE, Vitrohm etc. let me know. Probably i can bought them cheaper than in UK and even in Germany

Cheers

 

[Spencerleehorton]

Hi ln76d,

what type of switch should i be using for the C414 EB or the C414 B ULS the 3 way? is it SP3T? or DP3T?

regards

Spence.