400RB II with a DI Box

Sifl · #1 04-04-2011, 04:20 PM

I assume I can hook up a 1/4 cable from the unbalanced Direct Out on my amp to the input of a DI Box, then run the XLR to the mixer? Or is there a better way to set it up?

I just want to be sure before I end up blowing something up!

jaywa · #2 04-04-2011, 05:09 PM

Does the 400RB II not have a balanced (i.e., XLR) output onboard? Unless the amp in question is more than 7 or 8 years old that's pretty much standard practice with bass heads anymore.

No need for a DI box at all if that's the case. Plug a mic cord into the 3-pin socket on the amp, and off you go. If I'm not mistaken, on the newer 400RBs they've even moved that jack from the back to the front panel. Can't get any easier than that.

walker rosewood · #3 04-04-2011, 05:36 PM

Quote:

I assume I can hook up a 1/4 cable from the unbalanced Direct Out on my amp to the input of a DI Box, then run the XLR to the mixer?

Yep. A regular instrument cable to a DI box will do it.

Sifl · #4 04-05-2011, 10:45 AM

Quote:

Originally Posted by jaywa

Does the 400RB II not have a balanced (i.e., XLR) output onboard? Unless the amp in question is more than 7 or 8 years old that's pretty much standard practice with bass heads anymore.

No need for a DI box at all if that's the case. Plug a mic cord into the 3-pin socket on the amp, and off you go. If I'm not mistaken, on the newer 400RBs they've even moved that jack from the back to the front panel. Can't get any easier than that.

It's an oldie! All it has is an unbalanced 1/4" direct out

Quote:

Originally Posted by walker rosewood

Yep. A regular instrument cable to a DI box will do it.

Thank you!

walterw · #5 04-05-2011, 07:49 PM

and can actually sound pretty good, sending that passive DI box a strong active signal.

jaywa · #6 04-05-2011, 08:11 PM

So that unbalanced out is post EQ, then? Otherwise I'm not sure what you gain that way vs. Just feeding the direct box out of the bass.

prd004 · #7 04-05-2011, 08:24 PM

I would plug the bass into the direct box, and the thru from the DI to the amp.

jaywa · #8 04-06-2011, 08:32 AM

Quote:

Originally Posted by prd004

I would plug the bass into the direct box, and the thru from the DI to the amp.

Right, that's the standard way of doing it so I'm wondering what the benefit is to essentially reversing the chain.

Sifl · #9 04-06-2011, 09:55 AM

Quote:

Originally Posted by jaywa

Right, that's the standard way of doing it so I'm wondering what the benefit is to essentially reversing the chain.

If I'm understanding the threads about DI's is that you would want a passive DI for active basses and an active DI for passive basses. I have a passive bass and a passive DI. Therefore, I assume, if I go from the Direct Out to the DI this is essentially sending an active signal to the passive DI.

But if it doesn't matter, I will go bass->DI->amp.

Also, I am unsure if the Direct Out is pre or post eq.

jaywa · #10 04-06-2011, 10:48 AM

Quote:

Originally Posted by Sifl

If I'm understanding the threads about DI's is that you would want a passive DI for active basses and an active DI for passive basses. I have a passive bass and a passive DI. Therefore, I assume, if I go from the Direct Out to the DI this is essentially sending an active signal to the passive DI.

That thinking makes sense, and may work just fine. I can't see it harming anything unless the unbalanced out from the head winds up introducing noise into the signal. I just had never heard of anyone doing it that way before.

MNAirHead · #11 04-06-2011, 11:24 AM

If you send Post eq or preamp out to a DI box, any good sound guy will be kind of ticked at you.. many of these scenarios will change your FOH levels when you alter the knobs etc...

Better going clean and direct.

walker rosewood · #12 04-06-2011, 01:49 PM

^^^ False. That's just a stereotype. Any jaded, lazy, or un-knowledgeable sound guy will be ticked at you.

Yes most soundguys only take a DI from the bass instead of the head, but they have no clue why. It's one of those annoying 'traditions' that gets passed down without giving a reason, and young engineers just do it because 'that's the way you're supposed to do it'. So IMHO its the bad sound guys that do this, because they don't know any better. Furthermore, once they get that 'clean signal' they have no clue what to do with it, and butcher your tone, or completely buries it.

I think the rational is that an engineer knows their DI works, but they don't know if your amp is junk or not. So they don't take the risk. However, with just about every modern bass amp providing a built in DI, most of which sound fine, have a ground/lift switch, a -db pad, and have a pre/post switch if needed, there's really no good reason not to try it.

What I do is if the bassist clearly has nice gear, or an amp I'm familiar with, I take the DI from there head. And if they have an obvious attention to tone, I'll gladly use the post send. I leave a DI box sitting on top of their amp as a back up. If anything goes catastrophic, it takes .5 seconds to switch the connections.

Any good sound guy will know there's no one magic bullet for any situation. There's always variables. Take this situation for example, what if a kid comes in with a squire p-bass, but has a nice Ampeg head (say a svt-3pro). They probably get a decent sound through the amp and its onboard DI, but just DI'ing the bass sounds like, well, a squire.

Or how about any bassist that uses effects pedals? trust me, pedals sound different (and usually bad) if you go directly into a PA, then if they're running into the impedance of the amps input, and/or interacting with its preamp.

Anyway, to close the rant up. There were a lot of threads here about how soundguys take a straight DI, and refuse to mic a cab or take a post signal out, and how much that pisses off most bassists. (these threads all go down a bad road and were banned). I just want to say that as a soundguy, I hate that most soundguys do that.

p.s. this is a general rant derived from boredom, not directed at MNairhead or anyone else.

jaywa · #13 04-06-2011, 02:01 PM

Quote:

Originally Posted by walker rosewood

What I do is if the bassist clearly has nice gear, or an amp I'm familiar with, I take the DI from there head. And if they have an obvious attention to tone, I'll gladly use the post send. I leave a DI box sitting on top of their amp as a back up. If anything goes catastrophic, it takes .5 seconds to switch the connections.

Any good sound guy will know there's no one magic bullet for any situation. There's always variables. Take this situation for example, what if a kid comes in with a squire p-bass, but has a nice Ampeg head (say a svt-3pro). They probably get a decent sound through the amp and its onboard DI, but just DI'ing the bass sounds like, well, a squire.

Refreshing. Here we have a sound guy that "gets it". Sometimes the amp is part of the sound (or can help compensate for a less than pro grade instrument). It's nice to see there are FOH engineers out there who are willing to work with that and give the bass more than its typical two minutes of attention while taking the lowest common denominator, easy way out. Props to you good sir, and may you have many clients because of it.

walker rosewood · #14 04-06-2011, 02:01 PM

Quote:

Originally Posted by Sifl

If I'm understanding the threads about DI's is that you would want a passive DI for active basses and an active DI for passive basses. I have a passive bass and a passive DI. Therefore, I assume, if I go from the Direct Out to the DI this is essentially sending an active signal to the passive DI.

But if it doesn't matter, I will go bass->DI->amp.

Also, I am unsure if the Direct Out is pre or post eq.

Yes and no on the passive/active DI thing. A passive bass with a passive DI works fine. An active bass with an active DI is just adding an unnecessary gain stage.

Try to find the owners manual online, it should have a block diagram which will tell you if it's pre or post.

Sifl · #15 04-06-2011, 02:48 PM

Quote:

Originally Posted by walker rosewood

Yes and no on the passive/active DI thing. A passive bass with a passive DI works fine. An active bass with an active DI is just adding an unnecessary gain stage.

Try to find the owners manual online, it should have a block diagram which will tell you if it's pre or post.

Thank you! Now I know I can use the DI if my amp fails!

The older GK manuals don't really have much to them!

http://www.gallien-krueger.com/manuals/400rb.pdf

That's a link to the manual. It states that the effects loop is post eq, but pre boost and master. Not much is said about the Direct Out. Well, at least anything I can understand!

jaywa · #16 04-06-2011, 02:54 PM

Agreed, that manual is pretty much worthless.

If there's some way to communicate with GK customer service online, ask them in an e-mail. They should be able to tell you what type of signal is coming out of the direct out.

dhsierra1 · #17 04-06-2011, 03:10 PM

maybe this schematic can help? It's for the earliest version of the 400RB from what I can tell on the date. Looking at the schematic it looks like the direct out, located in the power amp section, is POST-eq. If memory serves you get a 0.5 v signal out at 600 ohms, unbalanced.

I don't have the preamp schematic, alas, but maybe poking around Google would be useful? I've found a lot of obscure schematics on other audio forums via Google.

Attachment 207637

**IvanMike** · #18 04-14-2011, 06:43 AM

To be fair, even a good soundman will get ticked at you (read you will be screwing with your own tone as well) If you use a post EQ DI signal AND keep messing with your settings. There's nothing like setting the trim etc for the channel and having the player jack up his bass knob from flat to full on three songs in...

As long as you avoid radical changes (as in mostly bass or gain increases) a post EQ DI is just ducky. The worst thing I or another soundman have to do is EQ your signal to sound good in the PA. This brings up the issue that the EQ you need for your bass cabinet(s) to sound the way you want your bass to sound are probably not the EQ settings needed to get "your sound" out of the PA speakers.

Slightly off topic - I must get one of these old GK 400RBs some day. I just had the chance to play through one a couple of weeks ago again and once again I was knocked out at how great that little head is.

Sifl · #19 04-14-2011, 05:23 PM

I just got a Whirlwind IMP 2 passive DI. I tried it going from the Direct Out on my amp into the DI and it's definitely post EQ. I also tried it with my bass into the DI and out to our practice PA and it sounded fine that way as well.

I never change my settings mid set, so I'll probably just run it Direct Out>DI>Mixer.

And I was a fan of this head from the first moment I played through it, which is the reason for this thread!