Little Mark III DI issue....

doktorfeelgood · #1 06-23-2010, 07:43 PM

I did a gig on Saturday that was an outdoor Blues Festiavl and for the first time since I've owned that LM III the DI from the back of my the amp was used by a soundman.
He had actually forgotten to hook me into the PA before we started our set and my rig was really sounding sweet. After the thrid song he noticed no bass in the FOH and came up to hook up the mic cable. Within 3 minutes of starting the next song I was getting some very weird things going on with my amp. Notes were cutting out and sometimes certain notes almost sounded like they were making a tremolo sound. That kept up for awhile and I could never figure it out. I was able to finish without any major problems so that was good, but I was wondering if anybody else has had any of those kinds of issues with their LM III. I did notice that the cord the soundman used to connect my amp to the snake had a funky end on it. The cable was loose at the connector on my end. I'm sure it could have been that. Was thinking maybe it also could have been an impedance mismatch. From now on I use my own 25 foot XLR cable to eliminate ant possible cord problems. Thanks for any thoughts on this matter. )-(

DWBass · #2 06-23-2010, 07:50 PM

He may have had phantom power on that channel causing the weirdness. Personally, I refuse to use on-board DI's! I always use a separate standalone DI box. Avoids any signal hassles!

Brad Johnson · #3 06-23-2010, 08:37 PM

Quote:

Originally Posted by DWBass

He may have had phantom power on that channel causing the weirdness. Personally, I refuse to use on-board DI's! I always use a separate standalone DI box. Avoids any signal hassles!

That's sounds likely though I've never had anyone do that.

I use my DI frequently on my LMII and so far no complaints. I've even A/B'd it live with various DI's (Countryman, etc.) and the sound techs agreed that it's more than fine. I don't tweak my pre's tone controls so pre/post doesn't really matter.

doktorfeelgood · #4 06-24-2010, 11:36 AM

Quote:

Originally Posted by DWBass

He may have had phantom power on that channel causing the weirdness. Personally, I refuse to use on-board DI's! I always use a separate standalone DI box. Avoids any signal hassles!

I had a soundman once hook up an XLR cable from the snake to the GK I was using and forgot to turn off the phantom power at the board for that channel and fried the DI section.
So yes, I have seen that before. I think I'm gonna get a separate DI. Any suggestions for a decent relatively inexpensive passive DI?
)-(

KJung · #5 06-24-2010, 11:40 AM

Quote:

Originally Posted by doktorfeelgood

I had a soundman once hook up an XLR cable from the snake to the GK I was using and forgot to turn off the phantom power at the board for that channel and fried the DI section.
So yes, I have seen that before. I think I'm gonna get a separate DI. Any suggestions for a decent relatively inexpensive passive DI?
)-(

I've used the DI in my MB heads many, many times with no problem. I don't think phantom power will hurt them, although I have no idea if mine has every been subjected to phantom power or not. My guess is, your issue was a bad cable.

You might want to also set that DI to pre EQ (there is a simple to move jumper labeled pre and post inside the amp). That will allow the MB DI to mimic a stand-alone DI like the JDI or Countryman.

If you are convinced you need a stand alone DI, the two 'industry standard' DI's IMO are the JDI for active basses (passive, transformer based DI) or the Countryman for passive (or active) basses. Both are small, affordable (in the $200 range), and totally pure and quiet.

doktorfeelgood · #6 06-24-2010, 01:07 PM

Quote:

Originally Posted by KJung

I've used the DI in my MB heads many, many times with no problem. I don't think phantom power will hurt them, although I have no idea if mine has every been subjected to phantom power or not. My guess is, your issue was a bad cable.

You might want to also set that DI to pre EQ (there is a simple to move jumper labeled pre and post inside the amp). That will allow the MB DI to mimic a stand-alone DI like the JDI or Countryman.

If you are convinced you need a stand alone DI, the two 'industry standard' DI's IMO are the JDI for active basses (passive, transformer based DI) or the Countryman for passive (or active) basses. Both are small, affordable (in the $200 range), and totally pure and quiet.

There are small push-buttons on the back of the LM III for pre or post EQ as well as ground lift. I did have it in pre-EQ and I tried the ground lift. I was figuring it was the cable as well. Thanks )-(

KJung · #7 06-24-2010, 01:12 PM

Quote:

Originally Posted by doktorfeelgood

There are small push-buttons on the back of the LM III for pre or post EQ as well as ground lift. I did have it in pre-EQ and I tried the ground lift. I was figuring it was the cable as well. Thanks )-(

I was thinking of the II... yes III is a good thing with that switch.

YellowJacket · #8 06-24-2010, 01:54 PM

Is there a thread that gives advice on a 10 step plan to keep gear from getting fried by douchebag soundmen? The more I read the more I realize many of these guys haven't been properly schooled on how to run gear. For sure they know their liner power amps, monitors, soundboards, mics, etc really well, but when it comes to guitar and bass gear, they do not have a proper understanding of how it works or what can possibly be a fatal mistake. I'm beginning to think the correct response to any soundman is "FU BUDDY, Mic my cab. Don't go NEAR MY AMP!

" Oh, if a venue provides house gear, USE IT! Let them cook their own crap! The reality of the situation is that nobody will be able to tell live.

An alternative is for a band to have a soundman that works with them all the time. If he's your friend, he is much more likely to give a rip! At least this way musicians won't have to pay the consequences for costly mistakes, at least until sound guys take their fingers out of their ears and LISTEN for a change.

DWBass · #9 06-24-2010, 02:04 PM

Maybe it's just me but I have had nothing but bad experiences with soundmen taking a direct feed from my amp's onboard DI (the couple times I used it)! One guy refused to use my separate box! Nothing but trouble all night. Kept telling me to turn down that he was getting a weird noise as well! I literally had my amp volume on 1! Never again! Use my box (or yours) or mic me! I use a simple passive DI box made by Pro-Co (DB-1) which I bought maybe 10 years ago! While onboard DI's are convenient, I don't trust them or the soundmen! I want complete control over my stage rig. Take my feed from my DI box and leave me alone!

emjazz · #10 06-24-2010, 02:05 PM

I love my LMII, but my DI out hasn't worked for something like 2 years or more. I need a DI so little at this point that I'm not willing to spend the money to fix it.

Be sure to take it to someplace that is a Markbass authorized repairperson. Good luck

Devo-lution · #11 06-24-2010, 02:08 PM

Sound guys occasionally tell me my LMII's DI out has a slight buzz... when I put on the ground lift, it's still somewhat present.

Also, when going direct out via the LMII, I find the sound to be more trebly then when going with a mike or DI box.

BurningSkies · #12 06-24-2010, 02:12 PM

IIRC we've discussed the phantom power on the DI issue for LMII's and it's supposed to be a non-issue. Designed to be safe even if someone has it on from the board. I've used the DI on numerous occasions to board with no problems or complaints in the sound. I've also used it in recording situations and not had any difficulties or errant noise.

KJung · #13 06-24-2010, 02:13 PM

Quote:

Originally Posted by Devo-lution

Sound guys occasionally tell me my LMII's DI out has a slight buzz... when I put on the ground lift, it's still somewhat present.

Also, when going direct out via the LMII, I find the sound to be more trebly then when going with a mike or DI box.

Do you have it set 'pre EQ'?

Devo-lution · #14 06-24-2010, 02:16 PM

Quote:

Originally Posted by KJung

Do you have it set 'pre EQ'?

Nope, not much of a technical wonder and never opened up the amp... Would it help a lot?

In that case, I'd give it a try...

KJung · #15 06-24-2010, 02:17 PM

Quote:

Originally Posted by Devo-lution

Nope, not much of a technical wonder and never opened up the amp... Would it help a lot?

In that case, I'd give it a try...

Yeah, I run my MB DI's pre EQ, and have never had any issue with noise.

PM on the way... it's easy!

Devo-lution · #16 06-24-2010, 02:19 PM

Quote:

Originally Posted by KJung

Yeah, I run my MB DI's pre EQ, and have never had any issue with noise.

PM on the way... it's easy!

Okay, thanks a bunch

9mmMike · #17 06-24-2010, 02:27 PM

Quote:

Originally Posted by Devo-lution

Sound guys occasionally tell me my LMII's DI out has a slight buzz... when I put on the ground lift, it's still somewhat present.

...

Same here. LMII and my LMIII. Very annoying.

KJung · #18 06-24-2010, 02:29 PM

Quote:

Originally Posted by 9mmMike

Same here. LMII and my LMIII. Very annoying.

Hmm... even with the LMIII set at pre EQ? Never have experienced this (and I work with some VERY picky sound professionals).

Rick Auricchio · #19 06-24-2010, 02:32 PM

Quote:

Originally Posted by Devo-lution

Sound guys occasionally tell me my LMII's DI out has a slight buzz...

Have you checked this with nothing plugged into the amp? Maybe they're hearing the sound from your bass.

DWBass · #20 06-24-2010, 02:33 PM

Quote:

Originally Posted by KJung

Hmm... even with the LMIII set at pre EQ? Never have experienced this (and I work with some VERY picky sound professionals).

Just to make it clear, my issues were not with my Markbass (or Genz Benz) amps. I'm at the point that I just don't use onboard DI's no matter what the amp.