Slaving with the Red Box Out to Slave Input: Wiring Diagram Req'd

Hey guys,

So, I'm currently using a 1/4" lead, from the FX Send of the TriAmp MKI, into the Hi-Gain Input of the Slave amp...
Now, I'd like to use both the FX Send/Return for a few effects, which leaves me no choice but to begin using the Red Box DI Out of the TriAmp...

To accomplish this hookup, I'll need to create an XLR to 1/4" lead to do this --- does anybody know if soldering pin's 1 and 3 are ok in this instance?

Thanks in advance, guys!
~Phil T

Hi Phil.  The Redbox out is a proper balanced XLR outlet as I'm sure you know.  It is fed from two opamps set to give equal +ve and -ve signals on pins 2 and 3 with pin 1 as the system ground.  Each side has an output impedance of around 680R which means that shorting it to ground either deliberately or accidentally is not a problem for the circuitry inside.  That leads to the quoted balanced output impedance of 1360R, (2 x 680R).

Just take a signal from either Pin 2 or 3 with Pin 1 as ground ignoring the other.  It does mean that the signal you end up with on the tip will be half of the balanced signal but that is a small difference in practice and there is no way around that unless you are feeding a balanced input with a TRS plug.  I've attached a decent pic I picked up online.

I would add that you should remember that it is a signal compensated to include the sound of output stages and speakers.  If you feed it into another guitar amp this is being added again for the second amp.  It was really intended to be fed into a bland flat PA or mixing desk input.  I'm not sure how that would sound having it passed through an output and speakers twice effectively.

EDIT:  Just checked and the Triamp actually has a better output stage for its Redbox than the GMs and TMs do.  It isn't two independent opamps, it is a correctly cross coupled pair making an instrumentation amp type circuit.  It's output impedance is a lot lower than the 680R of the GM series.  This is even better as the signal is not halved on using it with an unbalanced input as long as the other output is grounded as in the attached diagram.  The only downside is that the compensation for cabinet is not as comprehensive and up to date.  In your case this may also be an advantage.

Thanks for the very insightful response bordonbert, I really do appreciate you taking the time and explaining everything for posterity!

Okay, so... for the sake of posterity...

The lead from the Red Box DI Out, to the Slave amp's input is such a KILLER sound!
I did this years ago, before I had my H&K --- but the rig I have now... is just insane!

When I played some heavy riffing, I felt the Lows just pushing all kinds of air... and I can also feel the riser vibrating...

This worked out great!

Thanks again for your insight bordonbert!

Good stuff there, glad to hear it worked out. I was at a gig last night, an American singer Sari Schorr and her backing band. (Power Blues lovers should check her out if you don't know her already). The guitarist, Ash Wilson, was using a Duesenberg through a customised boutique 633 amp/speaker. He had it screened off with an acrylic amp shield and miced up of course. The tone was absolutely awesome even through a so-so PA. For myself, putting me through to front of house is a bit of overkill in the crowded bars and tiny clubs we play in but the idea of Redbox through a generic clean amp is very attractive as a way of getting reliably good tone. A decent bland amp and speaker is easy to produce nowadays and very scaleable, you could even have a range of them to suit different sized venues. If all of the tone is produced in the H&K and only the overall volume is down to an amp/speaker which is intended to add nothing to it it's a snip and very cheap too. I can't help but think that the PA route is the way most bands, big or not, are going to go in the future as it becomes more the "thing you have to do to get a decent mix" but, for me, the H&K Redbox/CleanAmp+Speaker could be more practical.

Your words doth intrigue me Phil!

[Just googled Sari Schorr... I'll update accordingly]...

Although I LOVE to play loud... it's not necessary for me. Especially with the TriAmp. I DO crank the green channel, to get a really ballsy Rhythm sound, the Master only goes loud enough for me to get a nice, controllable feedback [I'm a very psychedelic, and experimental guitarist]. I don't mind coming out of the PA, whatsoever! I'm all for balance... [as long as I can get the amount of volume that allows my feedback to sing...]

But adding the 2nd amp > powering a stereo pair of 15" JBL's > and by using the TriAmp's voice? HOLY SH*T MAN!!!
I'm telling you, I'm really impressed by this setup!

Okay, time to look up some Sari Schorr...

Thanks again, bordonbert!

Update on this topic...

Here's my Paint-Peeling Rig so far...