Topic: The AKG Actives Project

[willndmb]

OK, the next step is to build this into a collette at the mic capsule.  (So, does anyone have collettes for these capsules?)  Next I'll try to field test.

Thanks for your interest!

  Richard

you prob saw this...
http://taperssection.com/index.php?topic=59577.msg830670#msg830670

[Chuck]

RIchard how is that you accomplished this in a matter of days, where others have been struggling for much much longer? will adding length to the cables cause any issues at all? i am really impressed and can't wait to hear some samples.

of course you accomplish this right after I finally acquire some active cables 

Unfortunately, this is the point in the process where problems can creep in, such as RF interference, noise etc...
It looks like Richard has the quick and dirty part done. I'll bet that the refining takes a bit longer.

[poorlyconditioned]

RIchard how is that you accomplished this in a matter of days, where others have been struggling for much much longer? will adding length to the cables cause any issues at all? i am really impressed and can't wait to hear some samples.

of course you accomplish this right after I finally acquire some active cables 

Unfortunately, this is the point in the process where problems can creep in, such as RF interference, noise etc...
It looks like Richard has the quick and dirty part done. I'll bet that the refining takes a bit longer.

Someone help me with the collettes and we'll see how long it takes .

  Richard

[jeromejello]

Good job, Richard!  +T

Any chance of getting a crude schematic? 

Yeah, I'll post a "blackboard drawing" in a bit.

  Richard

looking forward to the blackboard...

you are a frickin haxor animal 

[fozzy]

RIchard how is that you accomplished this in a matter of days, where others have been struggling for much much longer? will adding length to the cables cause any issues at all? i am really impressed and can't wait to hear some samples.

of course you accomplish this right after I finally acquire some active cables 

Unfortunately, this is the point in the process where problems can creep in, such as RF interference, noise etc...
It looks like Richard has the quick and dirty part done. I'll bet that the refining takes a bit longer.

Someone help me with the collettes and we'll see how long it takes .

  Richard

Assuming it is a metric thread pattern, somone w/ access to a digital caliper could figure this out for us.
how far, in millimeters it advances in one turn of the cap will give you the thread pattern.  While you are at it accurate internal and external diameters of boddies/caps will also be needed.

hopefully this is a standard pitch so a tap could be purchased.  Soft brass would be pretty easy to work through and engineering a mount for the center pin would be pretty easy.

[thegreatgumbino]

RIchard how is that you accomplished this in a matter of days, where others have been struggling for much much longer? will adding length to the cables cause any issues at all? i am really impressed and can't wait to hear some samples.

of course you accomplish this right after I finally acquire some active cables 

Unfortunately, this is the point in the process where problems can creep in, such as RF interference, noise etc...
It looks like Richard has the quick and dirty part done. I'll bet that the refining takes a bit longer.

Someone help me with the collettes and we'll see how long it takes .

  Richard

Assuming it is a metric thread pattern, somone w/ access to a digital caliper could figure this out for us.
how far, in millimeters it advances in one turn of the cap will give you the thread pattern.  While you are at it accurate internal and external diameters of boddies/caps will also be needed.

hopefully this is a standard pitch so a tap could be purchased.  Soft brass would be pretty easy to work through and engineering a mount for the center pin would be pretty easy.

Isn't the thread info shown on the product data sheets as an m19 x 0.75?

[thegreatgumbino]

No they would not, because the AKG bodies have a FET in them already, what you see when you unscrew the cap is the connection between the FET and the capsule. 

You need a bare polarization voltage to transmit over a long enough distance to the FET at the capsule, there is no way to get that polarization voltage from the connector on the bodies.  This is what i've gathered from my ideas and experiments.

I don't know about that.  The ck_x caps have a FET in them if I remember correctly & they operate over the mk46.  Seems like the ck6_ could be operated in a similar fashion if a FET and ? was added in the collette.

[poorlyconditioned]

No they would not, because the AKG bodies have a FET in them already, what you see when you unscrew the cap is the connection between the FET and the capsule. 

You need a bare polarization voltage to transmit over a long enough distance to the FET at the capsule, there is no way to get that polarization voltage from the connector on the bodies.  This is what i've gathered from my ideas and experiments.

I don't know about that.  The ck_x caps have a FET in them if I remember correctly & they operate over the mk46.  Seems like the ck6_ could be operated in a similar fashion if a FET and ? was added in the collette.

Exactly.  You need to add *at least* one FET in the collette.  I've added two, one to acts an buffer/amplifier and one to act as a constant current source for the amp.  So, in the collette I will put: two FETs, two 1Gohm resistors and a few other parts.  For now I'm going to just seal it with copper foil/tape and see if that works.

I'll post results when I do this.  But in the meantime, if the person with the Collettes wants to get back to me, that would be much appreciated.

  Richard

[poorlyconditioned]

No guarantees, but here is the circuit I used:


I will post again if I build in/near the mic capsule.

  Richard

[fozzy]

Isn't the thread info shown on the product data sheets as an m19 x 0.75?

well that was easy.

Depending on how much realestate is needed in the collete it should be easy to work w/ a short run machine shop to get some made up.  The 1Gohm resistors are the bigest part in there(as pictured).  Depending on the wattage required/recomended they can be had as small as 1/4" by 1/4". 

[smokydays]

No guarantees, but here is the circuit I used:


I will post again if I build in/near the mic capsule.

  Richard

Incredible Richard, +T!

[poorlyconditioned]

OK, I've got contacts at the machine shop here to build Collettes.   That will begin 1 August.  I've also got a query out to someone on TS.com who has collettes already made.  Either way, this *is* going to move forward...

See you in August...

  Richard

[F.O.Bean]

thanks for your hard work gentlemen, i cnat wait for this to take off

[aberg]

Yeah, great work there Richard!

I live in the same town, so I'm hoping to see the progress on this first hand!

[rokpunk]

please let me (or us) know if you need anything to fund this research and development. i'm interested if it comes to fruition, but in the meantime, i'm willing to help fund this project (as i'm sure alot of us would) with money or parts or whatever.