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Question about active signal levels

B

bassface2

Jun 6, 2008
6
0
#1
I did try searching first, so my apologies if this has been covered, or is common knowledge.

I work a gig where they have 2 newer big Yamaha Boards. When certain bass players show up with some pretty nice basses, the sound crew has a hard time getting enough signal at the board, and have to boost everything, including gain pads, to get a usable sound.

They have a Manley preamp that everyone runs through, and I think everyone (ie, even the Fenders) are active.

One guy has a (lower line) Sadowsky and another has a Fender that seem to do fine.

Others of us have trouble getting enough signal: Warwick Thumb, Tobias Growler (USA Gigson), 2 nice Ken Smith's, and a nice Pedulla.

Since everyone plugs into the same stage box for switching (A or B -- OR -- A&B, box), I don't think that has any impact on the issue.

We use good "bass to the box cables" (I use a high quality Monster) others use the same or comparable. Nothing else changes.

No bass amp/cabinet is used (other than the Manely and House PA)

We've experimented with batteries, cables, strings, pick up heights, etc...

On the problem basses we are using the special +18 boost at the board option on the Manley, PLUS another 10db boost at the board (a 28 freaking db boost!).

The distance between the stage and the mixing board is about average for a 3500 seat auditorium, and it never changes. All lines are permanently installed and hidden. Only stage cables are exposed, and as mentioned, everyone uses the same set up except for their bass and first cable.

First: have other people noticed similar issues.

Second: What to do about it? I can use a small "head amp" at the pre pre stage, but this just seems ridiculous.

All I have right now is a Korg Pandora's Box to add in the line, what is a good pro level alternative at a reasonable price ? (couple of hundred $, more or less).


Thanks for any help
 
#2
There are loads of gain-boosting stompboxes for the unbalanced instrument-level signal into the DI, but realistically that shouldn't be necessary. There are also active DI's which are capable of gain boost, but again they are typically only "necessary" with basses that have low output.

What kind of DI are you using, anyway? Is it the big Manley for a bass DI?
Like: bass --> Manley --> snake input box --> mixing desk?

If not that, then where exactly is the Manley in the chain, and what DI is being used instead?
 
#4
Yes, it's the big rack size 2 channel Manley.

bass -cable -(switch box)-Manley-Snake-Board.

With the +18DB on.

I even changed strings the other night to see if that helped. No change, other than the brightness of the sound that you'd expect with new strings.

I could see 10 or even 15 db difference between basses. But even after we boost the problem ones +28, it's still just enough, may be a little difference in headroom between the different problem basses.

No other DI is used - it doesn't seem like you should have to boost the signal before the Manley.

I play the Thumb and the Growler and they hit my home board fine, though I use a various small preamps. I don't have a Manley or Avalon - "Yet" anyway :-)

And the strange part is, the other problem basses belong to some this city's first call players - guys that play large venues and record frequently.

Their axes are first rate, well maintained instruments, with histories of reliable performance. They just shake their heads in mild disbelief while the sound guys find ways to crank their signal up.

BTW: I run my pick ups at about 80-90 percent up. So do the other players, some probably a little hotter. If it were just my instruments, I would suspect the set up, but I even raised my pick ups on the Thumb, which helped a little, but not enough to suggest that it was the solution. Plus there would still be the issue of other guys.

I would think that the Manley would handle everything but instruments that were in bad disrepair ,or just junk to begin with. But everyone uses good pro level gear. Really the only questionable ones are the ones that send plenty of signal.

I'm logging out for the weekend but I'll check back Monday to see if anyone has offered up some insights.

Thanks again
 
#6
Also which specific Manley model is it? And it also occurs to me that this sounds like a wiring problem- e.g. the balanced connections are not all wired the same, or wired correctly. Note that some pro audio gear uses a different XLR pin as "hot", and I vaguely recall Manley was one of those brands. Check the manuals of both the Manley and the mixers, make sure you have identified the pinout of each, and double (triple) check that the cables used will match up those pinouts. And use a reliable cable-tester on every single cable. I'm still suspicious of the "switch box" too.
 
#7
If the Manley is a preamp , I would put it beside the board and pass the basses through a very good PASSIVE DI.
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The impedance of the cable run would be better and the soundman would have control over the gain of the unit.




Bass-Passive DI-snake-Manley-board
 
#8
In reply to a few of the recent replies:

The Manley has no model number or name on it, but says:
Dual Mono Tube Direct Integrated (something something)

Because of the fact that a few of the guys don't have issues (and for the most part they have the "cheaper" basses - not bad basses, just lower price points) and nothing but the bass (edit: guitar) changes, I don't think that it's the Manley or cabling. Plus we have tried different cables that cannect the bass to the A/B switch box.

The Morely AB Switcher box doesn't seem too likely since the regular guys (cheaper basses) use it constantly. It sends the bass signal to:

A = House (Bass>Cable>AB Switch>Cable>Manley>Cable>Snake Box & Snake>Patch Panel>Cable>Board)

B=Tuner (Bass>Cable>AB Switch>Cable>Tuner)

Note: You can also run it A-AND-B for constant signal to both destinations. Usually not done that way though.

Also:

I haven't asked the sound crew why the Manley is on the stage instead of at the board, but I think that is a good question. The DI idea might also be something to consider.

One thing .... I've started wondering is may be the regular guys both happen to run their Bass tone controls wide open giving it the appearance that their over all signal is hotter. Where as the other guys (including myself) set tone controls at a lower point.

... I know it sound simplistic, but who knows ...?

I don't care for a boom-ee bass tone, so I run my tone with what I consider tight low end, i.e., "low mids-to-mids punchy", but not cloudy (hence the Thumb Bass and my "Warwick Strung" Tobias Growler). I only run my tone controls a bit past the center detent, depending on the situation of course.
 
#9
bongomania said:
Also which specific Manley model is it? And it also occurs to me that this sounds like a wiring problem- e.g. the balanced connections are not all wired the same, or wired correctly. Note that some pro audio gear uses a different XLR pin as "hot", and I vaguely recall Manley was one of those brands. Check the manuals of both the Manley and the mixers, make sure you have identified the pinout of each, and double (triple) check that the cables used will match up those pinouts. And use a reliable cable-tester on every single cable. I'm still suspicious of the "switch box" too.
Click to expand...

I will check the pin outs - good idea.

I also confirmed with at least one of the "louder" basses that he was running all knobs at wide open throttle. That explains a few other issues not mentioned here. That would definitely make the System to appear as though it was getting a hotter signal.

I'm also going to measure the various output strengths on as many of the various (active) basses that I can, to see if there are large differences in the signal strengths.

Thanks for the ideas to everyone.
 
#10
Sounds to me like the manely doesn't like the basses that your having problems with. If nothing but the bass is changing I highly doubt it would be something like the phasing of the xlr (I get the impression there's no bass amp on stage) or the permanent cable runs.

Try using another DI is all I can suggest. If you can, try a passive DI since they're so simple that very few things can go wrong with them.
 
#11
Here is a troubleshooting technique I learned years ago. It's called halving the problem and it works very quickly.

Take your bass and it's cable up to the board and plug directly in and see what you get. If the signal is suddenly ridiculously hot then the problem is somewhere between the board and the bass. Get the next half of the series and plug it into the board...

Bass>Cable>AB Switch>Cable>Manley>Cable>Board

If your signal drops you know the problem is somewhere in here, so cut this path in half...

Bass>Cable>AB Switch>Cable>Board

On the other hand, if you do this Bass>Cable>AB Switch>Cable>Manley>Cable>Board and the signal does not drop then the problem is somewhere between the snakebox and the board.

Cutting your signal chain in half and testing halves is the quickest way to find the problem.

Good luck!

Charles
 

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