DI box transformer

[Chris S]

Does anyone know what sort of transformer goes into a passive DI box?

Thanks!

[Ansil]

that rat shack 1k to 8 ohms works fine.

[downweverything]

really? that doesnt seem right.  i dont know, just thinking about the impedance of the pickups and the impedance of the console, 1k seems lo for the input, and the 8 ohms seems more like a speaker load.  mics are typ 150ohms lines are 600ohms.  seems like youd have some undesirable tonal difference.

[Ansil]

really? that doesnt seem right.  i dont know, just thinking about the impedance of the pickups and the impedance of the console, 1k seems lo for the input, and the 8 ohms seems more like a speaker load.  mics are typ 150ohms lines are 600ohms.  seems like youd have some undesirable tonal difference.

mine works.  thats all i know

[downweverything]

im sorry me being a *&^*&^ has led me to completely neglect answering your question.  for most high end passive pro di's jensen impedance have been accepted as more of a standard (jensens are expensive though and just as good transformers can be found elsewhere).  they use 200k:1.5k, the 200k is well well above pickup impedance which i believe you want it to be and the 1.5k is more like the actual imput impedance of a console mic pre that accepts 150ohm lines.  Ansil sorry if i came off as rude, i just reread my post and i prob worded that totally wrong.  i just meant it seemed unusual to use those impedances, ive never tried it and it could be a better solution as i in no way claim to be an expert.  i just hoped to keep the discussion going so i could maybe learn a little more.  i actually love it when people prove me wrong.  its a great sign your learning something new.

[Ansil]

no worries.  maybe thats why mine sounds so sweet.  basically i never worryy too much about impeadance unless it is negatively affecting my circuit.

[downweverything]

yeah i definately think thats one of my biggest problems.  i think about shit too much and never just try it.  kudos for having the guts.

[Gilles C]

...is available in there.

http://www.whirlwindusa.com/tech03.html

http://psbg.emusician.com/ar/emusic_going_direct/

I would love to be like Ansil and be able to just connect and use if it sounds good (really, I mean it), but my mind just does not want me to do that.

So I would say that a 20k/150 xmtr would be best than a lower impedence xmtr if you don't want to affect the sound too much. But it also depends on the specs of the xmtr. The freq response and all, the Jensen xmtrs being the best ones of course. $$$

But R.G. Keen ( http://www.geofex.com/FX_images/spltr2.gif ) came up with a good cheaper compromise with the 42TM018 that he tested. I ordered a few from Steve Daniels ( http://www.smallbearelec.com/ ) and they are OK for me too.

Gilles

[Gilles C]

Most of the time, I use some sort of buffer (FET preamp) between my guitar and amp, so results could be different with a guitar connected straight. I could prefer a 200K/1.5K xmtr if I was not using such a buffer.

A xmtr added inside the box of  FET Preamp Cable (  http://www.till.com/articles/PreampCable/ ) is something that I like.

Gilles