Bypassing the Bart/Bart tone module?

davesisk · #1 04-12-2008, 07:34 AM

Hey folks:

I've been the proud owner of an LG-3005 for a while now.

Here's a pic for your enjoyment:

It has the Bart pups and Bart 3-band preamp (fairly new bass, so it's the current system). In the control cavity there is one additional seperate block that (as I understand it) is a tone-shaping module that is part of the Bart/Bart package. I have a feeling that this bass might have a bit of a different character with that Bart tone module bypassed (I love the thick lower mids, but I keep finding myself wishing the upper mids were more prominent and that the highs weren't quite so muted).

So, is it possible to bypass this tone module by simply jumpering a wire or two? I could see putting a bypass switch on the bass if I like how it sounds jumpered, but I'd certainly want to see how it sounds first. (Or perhaps I could use blend pot rather than a bypass switch for even more versatility.)

Just to be clear...I'm not talking about bypassing the Bart preamp itself...I'm talking about bypassing that additional block which is a tone module (presumably the electronic part that colors the pickup output).

Please let me know your thoughts or how-to's...thanks!

Dave

chadds · #2 04-13-2008, 01:21 PM

Is that a right foot in the frame? I like Roscoes but that shoe has sole!

atrapp · #3 04-13-2008, 01:54 PM

Quote:

Originally Posted by chadds

Is that a right foot in the frame? I like Roscoes but that shoe has sole!

that's no shoe, that's a boot!

maurilio · #4 04-13-2008, 01:55 PM

Quote:

Originally Posted by davesisk

Hey folks:

It has the Bart pups and Bart 3-band preamp (fairly new bass, so it's the current system). In the control cavity there is one additional seperate block that (as I understand it) is a tone-shaping module that is part of the Bart/Bart package. I have a feeling that this bass might have a bit of a different character with that Bart tone module bypassed (I love the thick lower mids, but I keep finding myself wishing the upper mids were more prominent and that the highs weren't quite so muted).

So, is it possible to bypass this tone module by simply jumpering a wire or two? I could see putting a bypass switch on the bass if I like how it sounds jumpered, but I'd certainly want to see how it sounds first. (Or perhaps I could use blend pot rather than a bypass switch for even more versatility.)

Just to be clear...I'm not talking about bypassing the Bart preamp itself...I'm talking about bypassing that additional block which is a tone module (presumably the electronic part that colors the pickup output).

Please let me know your thoughts or how-to's...thanks!

Dave

Nice piece of wood!

It is more complicated than just change some wiring (take a look at the Bart wiring diagram!).http://bartolini.net/instructions/el...mb/ntmb918.htm
What are the specs on that bass? If you need more high mids just turn the mid ctrl up (~850hz). You could also change the Cap on the switch to raise the frq (~1000hz).

M

JOME77 · #5 04-14-2008, 05:32 AM

If your talking about a passive/active switch, unfortunately the impedence of the Roscoe Barts don't allow for them to be run in the passive mode (at least not in an efficeint manner;very, very low output).

If you want to simply bypass the tone controls and take an active flat signal to output.....that would be difficult because I believe that the overall frequencys are split into 3-bands internally within the Bart epoxy module.

Maybe Gard can provide more clarification......

CrashClint · #6 04-14-2008, 07:16 AM

Here is what I found out about wiring the pickups straight to the jack. A while back, I bought a Demeter preamp directly from Demeter with the Roscoe specs. They told me I would have it in two weeks which almost turned into two months. Well, thinking it was going to be here in two weeks I pulled the bart pre out. Well, I had to play my bass on a Sunday morning so I wired the pickups directly to the jack. Plugged into my amp released the -12db pad I normally use for active electronics and was pleasantly surprised at the volume coming out. To me the difference between the active and passive equals to using and not using the pad on the input. So if you wire a bypass make sure to release the pad or you will have a big drop in volume.

Gard · #7 04-14-2008, 08:31 AM

Quote:

Originally Posted by JOME77

Maybe Gard can provide more clarification......

....electronics?!?!?!?

...look, pretty flower!!!!

(runs away)

I don't believe that you can bypass just the controls but keep the active circuit in the loop. You can bypass the entire preamp, but as Joe points out, and Clint kind of reinforces, doing so will cause a very noticeable drop in output, too much to be useful in most real-life gig situations.

For any further information, I would have to refer you to Bartolini...

davesisk · #8 04-14-2008, 06:12 PM

Hey guys:

Yeah, I'm NOT referring to bypassing the whole active preamp. There is a seperate "black box" in the control cavity that is NOT part of the NTMB-3 preamp. Check your Bart-equipped basses and see if you see what I'm talking about. That's the component I'm talking about bypassing.

I will try to give Bartolini a call and see what they say.

Thanks for all the commentary,
Dave

maurilio · #9 04-14-2008, 07:07 PM

We know what you are referring to. Did you even check the link I posted? You can't not bypass that module without rewiring the whole mid and treb section and it would be like setting flat the ctrls. You'll end up with a TBT system: Bass and Treble only.
Believe me, I've tried it already, if you are looking for a different sound, swap the pre with something else...

M

JOME77 · #10 04-14-2008, 07:51 PM

Quote:

Originally Posted by maurilio

We know what you are referring to. Did you even check the link I posted? You can't not bypass that module without rewiring the whole mid and treb section and it would be like setting flat the ctrls. You'll end up with a TBT system: Bass and Treble only.
Believe me, I've tried it already, if you are looking for a different sound, swap the pre with something else...

M

And when Maurilio states that he's tried it already, he means that he's tried absolutely every possible configuration!

I don't think that he left any stone unturned...........

Got to admire a man that's willing to experiment though!

maurilio · #11 04-14-2008, 08:21 PM

Quote:

Originally Posted by JOME77

And when Maurilio states that he's tried it already, he means that he's tried absolutely every possible configuration!

I don't think that he left any stone unturned...........

Got to admire a man that's willing to experiment though!

Me?

nah!

Wassup Joe?

Indeed, I've tried probably all the combinations! For me it's like a hobby, on my free time I like to mess around with these electronics... used to be my job, you know!

BTW, right now my Roscoe is wired in parallel with the Demeter pre! Love it!
I'm actually using this bass for every style of music I'm playing

M

davesisk · #12 04-14-2008, 10:01 PM

Oooooh! I see (from the diagram)...those two blocks actually make up the preamp/EQ in it's entirety, with the unlabeled block essentially handling the highs and mids. Got it...I had a misconception about what that (in my bass) unlabeled block actually did. Thanks for clearing that up, M! Much obliged.

Hmm...well, let me think this over then.

Dave

Gard · #13 04-15-2008, 08:57 AM

Thanks for getting in and getting your hands dirty on this one Mo & Joe (hey, it's the Mo & Joe Show!!!

), I really don't "get" this stuff at all...I just plug 'em in and play 'em. My only input would be a) it works!!!

and b) it sounds good/bad/meh

. After that, I don't know nuttin' 'bout birthin' no babies, Miz Scarlett!!!