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Author Topic: What's an active cable comprised of????  (Read 11535 times)

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Offline Evil Taper

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Re: What's an active cable comprised of????
« Reply #15 on: January 24, 2006, 08:25:11 PM »
What we're forgetting here is that JK Labs was not a taper or even a recording geek, yet his products work great and according to the users sound nearly identical to the mic bodies.  The box that the cables plug into is very basic and there's nothing secret about it, it was probably built from a schematic he found somewhere.  I doubt that loads of research went into the building or refining end of the products so in that sense the results could be replicated fairly easily.  I'm just trying to open the door here, this knowledge hasn't really been discussed before and I couldn't find any real info about active cables anywhere.  Just like anything else, it can be done by the right people. 

Any idea of how different the systems would be from MG to Schoeps to AKG to Neumann?
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Offline poorlyconditioned

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Re: What's an active cable comprised of????
« Reply #16 on: January 24, 2006, 08:49:32 PM »
What we're forgetting here is that JK Labs was not a taper or even a recording geek, yet his products work great and according to the users sound nearly identical to the mic bodies.  The box that the cables plug into is very basic and there's nothing secret about it, it was probably built from a schematic he found somewhere.  I doubt that loads of research went into the building or refining end of the products so in that sense the results could be replicated fairly easily.  I'm just trying to open the door here, this knowledge hasn't really been discussed before and I couldn't find any real info about active cables anywhere.  Just like anything else, it can be done by the right people. 

Any idea of how different the systems would be from MG to Schoeps to AKG to Neumann?

Hey, Evil.  I agree entirely.

The contents of gear, and modifications to gear should be *open knowledge*.  This serves several purposes.  First, consumers know what they are getting is genuine and that the price is fair.  Second, DIY types can build and/or improve the design.

Some may say that "trade secrets" should be protected, but I think people will still pay reasonable prices for modifications, either to support the inventor or because they cannot do the mods themselves.  A good example is leegeddy's Nak mods and VR boxes.  He has made the plans public, but still has a steady stream of customers.  Yeah, there is a small chance someone else will "steal" the design and undercut the original.  But I think a community like TS.com can easily sort this out.  The designs will be replicated eventually anyways.

So, all you people get out there and start hacking gear.  And shows us the innards of gear you've got already!!!

  Richard
Mics: Sennheiser MKE2002 (dummy head), Studio Projects C4, AT825 (unmodded), AT822 franken mic (x2), AT853(hc,c,sc,o), Senn. MKE2, Senn MKE40, Shure MX183/5, CA Cards, homebrew Panasonic and Transsound capsules.
Pre/ADC: Presonus Firepod & Firebox, DMIC20(x2), UA5(poorly-modded, AD8620+AD8512opamps), VX440
Recorders: Edirol R4, R09, IBM X24 laptop, NJB3(x2), HiMD(x2), MD(1).
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Offline SparkE!

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Re: What's an active cable comprised of????
« Reply #17 on: January 24, 2006, 09:28:16 PM »

So, all you people get out there and start hacking gear.  And shows us the innards of gear you've got already!!!

  Richard


OK, I'll start.  Here's the innards of my ODL-276:




And here's the schematic:



And here's the innards of my Superlux SMK-H8K mics:




And here's some mics that I made:





How'm I supposed to read your lips when you're talkin' out your ass? - Lern Tilton

Ignorance in audio is exceeded only by our collective willingness to embrace and foster it. -  Srajan Ebaen

Offline SparkE!

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Re: What's an active cable comprised of????
« Reply #18 on: January 24, 2006, 09:34:50 PM »

So hypothetically.. if someone spends a hundred hours developing an MT mod that solves the noise floor problem using $20 in parts.. And they sell it for $200. Are you suggesting that copying their work, or posting a how to, is fair game?


Did you notice that I didn't post the schematics to my homemade mics? ;)  They've got programmable attenuators, switchable bass roll-off and a power switch for each channel.  They've got the Linkwitz source follower mod.
How'm I supposed to read your lips when you're talkin' out your ass? - Lern Tilton

Ignorance in audio is exceeded only by our collective willingness to embrace and foster it. -  Srajan Ebaen

Offline it-goes-to-eleven

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Re: What's an active cable comprised of????
« Reply #19 on: January 24, 2006, 09:35:10 PM »
Someone posted these a while back. Can't recall who.  The Neve Portico..  Just a couple trips to rshack and you'll be set!



Offline Evil Taper

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Re: What's an active cable comprised of????
« Reply #20 on: January 24, 2006, 09:38:49 PM »
since JK Labs is no longer building or supporting his gear why not have someone else do the job.
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Offline poorlyconditioned

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Re: What's an active cable comprised of????
« Reply #21 on: January 24, 2006, 09:48:37 PM »
Quote
What we're forgetting here is that JK Labs was not a taper or even a recording geek, yet his products work great and according to the users sound nearly identical to the mic bodies.

Let's not forget that he's history and is no longer supporting his products.

The contents of gear, and modifications to gear should be *open knowledge*.

So hypothetically.. if someone spends a hundred hours developing an MT mod that solves the noise floor problem using $20 in parts.. And they sell it for $200. Are you suggesting that copying their work, or posting a how to, is fair game?


I say copying *personally* is OK.  It is unlikely a DIY type is going to pay big bucks anyway.  Now, selling to others is touchy, and most genuine DIY types are not likley to do that.

BTW, I *did* make public my AKG CK91/93 actives, my 3-wire battery box, and my preamp/batt box.  So, I am contributing to the community as well.

What pisses me off if people charging outragious prices and not disclosing what is inside.  For that I will reverse engineer.  Just for the challenge of it!

  Richard
Mics: Sennheiser MKE2002 (dummy head), Studio Projects C4, AT825 (unmodded), AT822 franken mic (x2), AT853(hc,c,sc,o), Senn. MKE2, Senn MKE40, Shure MX183/5, CA Cards, homebrew Panasonic and Transsound capsules.
Pre/ADC: Presonus Firepod & Firebox, DMIC20(x2), UA5(poorly-modded, AD8620+AD8512opamps), VX440
Recorders: Edirol R4, R09, IBM X24 laptop, NJB3(x2), HiMD(x2), MD(1).
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Offline poorlyconditioned

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Re: What's an active cable comprised of????
« Reply #22 on: January 24, 2006, 09:56:16 PM »

So, all you people get out there and start hacking gear.  And shows us the innards of gear you've got already!!!

  Richard



And here's some mics that I made:







Those are beautiful mics.  I love your bodies/windscreens.  The build of the battery box looks excellent too!

Now here is a prime example.  You told me what is inside (in another post further down), and did a great job building them.  If you started selling them here there would be a market.  Certainly better than CoreSound or others who won't even tell you what is inside.

  Richard
Mics: Sennheiser MKE2002 (dummy head), Studio Projects C4, AT825 (unmodded), AT822 franken mic (x2), AT853(hc,c,sc,o), Senn. MKE2, Senn MKE40, Shure MX183/5, CA Cards, homebrew Panasonic and Transsound capsules.
Pre/ADC: Presonus Firepod & Firebox, DMIC20(x2), UA5(poorly-modded, AD8620+AD8512opamps), VX440
Recorders: Edirol R4, R09, IBM X24 laptop, NJB3(x2), HiMD(x2), MD(1).
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Offline SparkE!

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Re: What's an active cable comprised of????
« Reply #23 on: January 24, 2006, 10:01:32 PM »

What pisses me off if people charging outragious prices and not disclosing what is inside.  For that I will reverse engineer.  Just for the challenge of it!

  Richard


Agreed. And besides you can learn a lot from the work of others.  That's the whole premise behind our educational system.  We're pretty much sophisticated monkeys here.  Monkey see, Monkey do.  There's not too much Monkey see, Monkey independently and  extemporaneously formulate a brilliant solution going on these days.
How'm I supposed to read your lips when you're talkin' out your ass? - Lern Tilton

Ignorance in audio is exceeded only by our collective willingness to embrace and foster it. -  Srajan Ebaen

Offline Evil Taper

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Re: What's an active cable comprised of????
« Reply #24 on: January 24, 2006, 10:13:40 PM »
so...back to the original issue...how to build a custom active cable for MG mics
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Offline SparkE!

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Re: What's an active cable comprised of????
« Reply #25 on: January 24, 2006, 10:25:42 PM »

I've been taking stuff apart all my life.. The more secrets it has, the better.


Yup. Me too.  I took my toys apart as a kid and usually made them better.  I even took the football apart once, but I'm not sure that it got better.  That thing wobbled pretty bad after that.
How'm I supposed to read your lips when you're talkin' out your ass? - Lern Tilton

Ignorance in audio is exceeded only by our collective willingness to embrace and foster it. -  Srajan Ebaen

Offline SparkE!

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Re: What's an active cable comprised of????
« Reply #26 on: January 24, 2006, 10:40:46 PM »
so...back to the original issue...how to build a custom active cable for MG mics

OK, if I was doing it, I'd probably be looking for an amplifier that's more linear than the JFET amp in the active Schoeps cable's mic element adapter.  There are some new (at least new to me) amps from National that are designed for this type of thing:

http://www.national.com/ds.cgi/LM/LMV1032.pdf

The specs aren't great, but it makes me wonder if there are other similar designs out there that would have better S/N.
How'm I supposed to read your lips when you're talkin' out your ass? - Lern Tilton

Ignorance in audio is exceeded only by our collective willingness to embrace and foster it. -  Srajan Ebaen

Offline Todd R

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Re: What's an active cable comprised of????
« Reply #27 on: January 24, 2006, 11:49:31 PM »
What we're forgetting here is that JK Labs was not a taper or even a recording geek, yet his products work great and according to the users sound nearly identical to the mic bodies.  The box that the cables plug into is very basic and there's nothing secret about it, it was probably built from a schematic he found somewhere.  I doubt that loads of research went into the building or refining end of the products so in that sense the results could be replicated fairly easily.  I'm just trying to open the door here, this knowledge hasn't really been discussed before and I couldn't find any real info about active cables anywhere.  Just like anything else, it can be done by the right people. 

Any idea of how different the systems would be from MG to Schoeps to AKG to Neumann?

Jon may not have been a taper or recording geek, but that doesn't mean he isn't an audiophile or doesn't know his stuff.  I believe he did sonar engineering on a Norwegian sub.  At any rate, I've had a number of interchanges with him and have also gained alot from the posts he used to make on this board.  I think you are way, way off base to think that he did not spend alot of time on doing designs, using his ears, along with his training, to discover what worked best.  And he certainly did not just build stuff from a schematic he found somewhere. 

My AKG ECMS box is the ECMS-22.  I talked to him about why he named it this and it turns out it is the ECMS-22 since it was his 22nd revision of his ECMS design (Extended Capsule Microphone System).  From what I gather from my interchange with him, he tried lots and lots of different parts in the design to find what sounds best.  BTW, to my ears, my ECMS-22 does not sound like my 480 bodies.  I think it has better clarity and detail, but it is definitely not the exact same sound as the 480s.  (I would like to do a good comparison to the JWilliams mod 460s at some point.)

I'm not sure what this all says about reverse engineering, but I do think it is quite reasonable for someone who puts this much time and development cost into making a design for market to price that product in a way that captures this R&D effort (ie, not just priced on the cost of the parts used in the design).

And all this is not to say that your friend (or someone else) cannot build a good mic active system.  But it will probably be much more than just finding a schematic somewhere.  It's going to require prototyping and testing out different combinations of different parts to find what sounds best.
Mics: Microtech Gefell m20/m21 (nbob/pfa actives), Line Audio CM3, Church CA-11 cards
Preamp:  none <sniff>
Recorders:  Sound Devices MixPre-6, Sony PCM-M10, Zoom H4nPro

Offline Evil Taper

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Re: What's an active cable comprised of????
« Reply #28 on: January 25, 2006, 12:49:17 AM »
Thanks Todd.  If I knew my electronics stuff and had some skills in that department I'd devote alot of free time to building my own unit from scratch.  However, that's just not possible right now.  Haven't you attempted to put your abilities to work in making some custom gear for yourself before?
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Offline dactylus

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Re: What's an active cable comprised of????
« Reply #29 on: May 01, 2011, 05:47:19 PM »

.
reference
hot licks > microphones > recorder



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