This might be what you are looking for
http://mixonline.com/gear/reviews/audio_radial_studio_guitar/

Does a passive DI not work in reverse?
If I've misled at least two people in another thread...

I thought (considering my rudimentary understanding of the circuit) that a passive DI worked in either direction, but since I had only seen them work in one direction, and since I had never really looked at how they were constructed in real life - I thought I'd ask.

BTW the Radial set looks nice. Active DIs powered without phantom and with a "drag control" load correction. If they work well as ordinary DI's it would be a pretty good deal to get a pair of Radials for $260. If they are basically only good for the one job, it's pretty pricey.

Bob:
I have had good results using a Seymour Duncan Pick-Up Booster to run an extended-length cable from the control room to a hallway and a bathroom. Even with a 30-foot cable, I've had no noise issues. In fact the little box is capable of driving my vintage Fender Dual Showman Reverb head to new heights of locomotive tonality never before imagined...:)
And it's worked well on a passive bass/Ampeg V4B rig, too.
$75.00

I use ART Isolating transformers to eliminate ground loop problems in the mobile recording rig. These can definitely be used in either direction Bal>Unbal or Unbal>Bal, I am not certain but I believe this is the same type of circuitry involved in passive DIs. To quote from the reviewer in the link from the previous post:

"There's also a nice feature that lets you add an impedance load (Drag™) to your pickups that you'd normally lose by running it through a transformer or two"

I also read that there is a good deal of tone loss, in long cable runs over 25' while doing research regarding large stage layout.
Where there seems to be some disagreement is exactly what tone range that loss occurs in, most seem to say that loss occurs in the low to mid range area others say in high frequencies.

I don't really know how long your run is and what if any loss would be acceptable. The SD pick up booster is really a tiny preamp boosting gain supposedly (in their literature) without any signal alteration, I find it hard to believe that they can do this for less than $100.00 but hearing is believing.

If you already have 2 passive DIs why not try it it and A/B it?

Bob, I was really surprised to see a question like this come from you? I certainly wouldn't disturb the wine. That's inhuman! I may have to contact the SPCW on you? (Society to prevent cruelty to wine).

Here's my take on your mathematical dilemma.

Guitars with passive pickups need to see the high impedance load that tubes provide. A DI transformer will generally not be higher than 50 K ohms. It will affect the tonality. But an active pickup with a JFET input will present the pickups with the proper load, high. And you'll probably need to power that active DI with an internal battery, since you will not be providing phantom the box. Then to the amplifier via XLR cable up to 1000 feet, to a balanced bridging transformer that's 1:1 and say 10,000 ohms, each side.

I use transformer direct boxes in a bisexual way as they are bisexuals. Every transformer is.

But why make it difficult on yourself? Why not just keep the amplifier close by. Then you can send a speaker down a mine shaft 100 feet down without having to worry about any loss? Low impedance unbalanced speaker cables will travel the distance better than a guitar pickup.

Not picked up in years
Ms. Remy Ann David

Well that would work for a Marshall stack but not for a Fender Twin, but maybe you could put the guitarist and the amp in the isolation booth.

Engineer (on the talkback): Each progressive take seems to be a little bit sloppier.
Guitarist: What the *%$#, this the besht I've ever played, hic.

Final bill; 2 hrs tracking @ $50.00, three bottles of wine $350.00.

I guess the impedance issue is why the techs at Radial thought to develop the boxes.

Yes Remy, I realized it is a bit of a dumb question, but I was trying to think of ways to do this without spending any money, so that left out all of my active DIs, which require phantom. (There must be a joke about phantom power on bisexual DIs but I can't come up with one). My two amps right now are combos - a Fender Blues Jr. and a Matchless Hurricane. I had not thought about the fact that the Matchless has a amp/speaker connection even though its in the same cabinet. That's clearly the "right" way to go, even if I have to buy a cabinet. I don't have a separate cabinet, but I think I'll look into that. Does anyone have any suggestions for a cabinet to go with the Matchless Hurricane? Think I'll start another thread.

As far as a guitarist in the wine cellar - never gonna happen. I'll just keep the speaker pointed away from the 1985 Bordeaux and everything should be all right.

"everything should be all right." - the 1985 Bordeaux at least.

If you can't split the amplifier head from the speaker cab, I think I would try an active battery-powered DI box at the guitar end and a passive (transformer) DI box in reverse at the amp end, linked by XLR mic cable with a sex changer. You certainly need the inverse DI at the amp end, otherwise you will not get enough signal amplitude for the amp to run at the usual settings and without extra hum and noise.

Why do you need another speaker cabinet? You already have a second cab with the Blues Jr. Just run a cable from the Matchless amps speaker out to the Jr's speaker (the speaker disconnected from the Blues amp of course).

I do it all the time. I run my 1-12 boogie to my 2-12 Marshall or my 2-10 Fender to my 1-8 Gibson. It works great and makes each amp that much more versatile. Just keep an eye on impedances and you should be fine

Good Luck!

Big_D wrote: Why do you need another speaker cabinet? You already have a second cab with the Blues Jr. Just run a cable from the Matchless amps speaker out to the Jr's speaker (the speaker disconnected from the Blues amp of course). ...

Great minds think alike! I had decided to do just that as a test. Unfortunately, on Sunday a pipe burst in a corner of the studio and I had a minor flood. I caught it in time and I don't think anything important was damaged, but the studio is a mess. I might get a chance to try it later in the week.

I'm a musician first (like you) so I tend to try to get my sound right before I ever set up a mic, picking an amp first and then moving on to the speakers.

Besides the 4 combo amps I have I also have a couple of stand alone cabs with different speakers and when I'm trying to get a sound I tend to switch cabs before I switch mics. The difference is much more pronounced than a mic or pre change and I can hone in on a sound faster that way.

And yes great minds do think alike!!!

Good luck and let us know how it turns out

[quote=BobRogers] (There must be a joke about phantom power on bisexual DIs but I can't come up with one)quote]

Bob,
I think you've found a new tag line. It's not as good as the camel ride gig, but....

Phil

Does it involve AC/DC in some kinky way?

moonbaby wrote: Does it involve AC/DC in some kinky way?

Define "kinky"

UPDATE: On second thought - please don't!