Topic: at853 HACK pics

[Nick's Picks]

hey all...

I picked up some SP flavored at853s (back where I started) for some upcoming stealth shows I have planned, and am playing around with them in hopes of souping them up a bit.
Looking for suggestions.

I know the obvious, and that is phantom power.
those Samson adapter jobies reqiure a mini 3pin on one end, so you need to cut the stock cable and mount that.  I shortened my cables down to 8' and mounted them in a single techflex sleeve for ease of use.  Plus, thats my thing.  ;-)

so i'm all set for the phantom adapters, and I'll rig up some cables to run 1/4" into my MicroTrsher.
I've also got in my arsenal a denecke ps2 that I adapted to a 1/8" stereo mini output, fwiw. 
Wonder if I can hack those samson things and just hard wire the cables right in?  I'll have to check that out.  it be nice to eliminate all these mini xlrs.  I hate working w/them. 

What I'd like to do....
build me a battery box (probably just disect one of the several that I think I have laying around) and mount it in a new plastic project box with surface mount mini XLR female jacks so the mics can plug directly into this box for 9v power.  Behind this, I'd like to use the Hosa or AT line transformers...and this is where things get tricky as I'd like to disect those too and see if I can mount the guts in the project box.  From here, probably just a hard wired stereo mini out of the box. 

I think its a good idea, but i'm not sure its possible to accomplish all of this and have it inside a single small box.  Sort of like a custom little  fixed gain preamp.
Or, I could just get one of the SP preamps
 
Anyone have any thoughts to toss in?
 

[Nick's Picks]

whoops....
forgot the pics

[larrysellers]

Nice switchblade Fonzie 

[Nick's Picks]

Aaaaaaaaaa!

one of several.
 

[Zaphod]

So you want to build a box that gives the ATs 3-wire power then has transformers to bump up the signal? That'd be sweet. +T for the experimentation.

Re: Samson adapters, I don't know if you can hard wire the mics to them, but I know you can do it with the AT adapters.

[jeromejello]

can you use line transformers with battery boxes... i thought you needed p48 to drive them?

[poorlyconditioned]

can you use line transformers with battery boxes... i thought you needed p48 to drive them?

Transformers do not work well with battery boxes.  The problem is the mics have a pretty high output impedance (something like 10K, if from a battery box).  The transformers have a low input impedance.  Basically, what you gain from the transformers, you lose from the impedance mismatch.  It works, it just doesn't add much/any gain.

So, you really have two choices:
- mics > phantom adapters > PS2 > tranformers > recorder
- mics > preamp(*) > tranformers > recorder

The preamp here could be 0dB gain, but something to lower the impedance.  A simple opamp follower would work.  But if you're going to do that, you might as well just put a 20dB fixed gain in the preamp and skip the transformers.

  Richard

[Nick's Picks]

hmmmm...
thats the info I was looking for.
fixed gain might just be the way I go then for the non-phantom path.

[Nick's Picks]

anyone ever use the CS mic2496 box?

[poorlyconditioned]

hmmmm...
thats the info I was looking for.
fixed gain might just be the way I go then for the non-phantom path.

Yeah, I think fixed gain with a 3-wire battery box.  Hmm.  But that is close to what Church audio has!

Another idea would be to try to build your own phantom circuit and transformers, all in one case.

  Richard

[bdasilva]

Chris (Church Audios) little preamp could be setup to do three wire and give a nice 20db of fixed gain....

[yossi3080]

Sweet!!  Nick, I like what you did with my mics   Me very bad at the stealthing thing, so it didn't pay to keep them around anymore, not with my wonderful KM184s.  And thanks for the Hydra cables in trade-they are super cool, I can't wait to use them!

Yossi

[poorlyconditioned]

Another idea: Add a single transistor as an output buffer.  This could be either in the mic body or in the battery box.  The output would then have low enough impedance to drive a transformer.

It might even benefit other mics to add a buffer transistor of some sort.  I've heard rumors that DPA 406x mics do this, but I have not taken one apart to find out.  I don't even own these.

But it might just be easier to get a stock preamp somewhere.  I don't have the right test equipment either.  Sure I can build stuff, but you need test equipment to make sure it is working right.

  Richard

[Nick's Picks]

nor do I...
and I can't really build stuff either, I just like to think I can.  I have the ideas, but lack the implimentation skills.  still, i'm ambitious.

[Nick's Picks]

oh, and thanks Yossi.
I"m glad you like the cables.  I'm going to get some great usage out of the ATs too.