G&L + Genz Benz shuttle.. need some advice

[coop]

This post may belong in the "amps" subforum, but I thought you guys might know more about the rather "agressive" nature of MFD pickups.

I just got my Genz 6.0 -12t shuttle combo and while I think I'm going to love it, there are some things I'm not 100% thrilled with. I run my L-2000 and L-2500 with both pickups on, series (bass boost), and passive. Then I roll the bass and treble off to match the room. The Shuttle is great , but it seems to "break up" and distort pretty quickly. I don't mind a touch of grit, but I much prefer a clean strong deep tone.

Okay here's the question part: Should I look into trying some different tubes? Maybe a 12AU7 or a 5751? Different 12AX7? I think there's a Sovtek JJ in there now, I've got a Ruby, and a Shuguang on hand. I've heard good things about Telefunken.

On a related note: Could a bad tube cause 60 cycle hum in an amp? My old Hartke sounds like an angry beehive.

Thanks in advance for your help.

[Ken Baker]

Originally Posted by coop

I run my L-2000 and L-2500 with both pickups on, series (bass boost), and passive. Then I roll the bass and treble off to match the room. The Shuttle is great , but it seems to "break up" and distort pretty quickly. I don't mind a touch of grit, but I much prefer a clean strong deep tone.

You didn't mention how you have the volume set, but I'll bet it's pretty high if not wide open. A G&L L series bass in series mode with the volume dimed will SLAM pretty much any preamp into distortion - even passive. I'd recommend backing the onboard volume off to about 70% and the amp's preamp gain to about 50% and make small adjustments from there. Also, don't boost the amp's EQ too much either.

Okay here's the question part: Should I look into trying some different tubes? Maybe a 12AU7 or a 5751? Different 12AX7? I think there's a Sovtek JJ in there now, I've got a Ruby, and a Shuguang on hand. I've heard good things about Telefunken.

If the amp is new, I'd assume that the preamp tube is good and just leave it alone.

On a related note: Could a bad tube cause 60 cycle hum in an amp? My old Hartke sounds like an angry beehive.

Maybe, but probably not so much. 60Hz hum is usually a grounding problem. If it's happening with multiple amps in the same location, it's best to look to the location and your cables for a cure. (1) Make sure that the power circuit feeding the amp is in good shape and well grounded. THIS IS A SAFETY ISSUE AS WELL! (2) Check your cables to verify that they are in good condition. (3) Fluorescent lighting can also cause noise, though this will usually have a higher frequency component. Not much you can do here except shield your basses or turn the lights off.

Ken...

[coop]

Hi Ken,

Thanks for your reply. A few more details -

I've owned approx. 15 G&Ls over the last few years. Your G&L history?. Yes, I run my volume fairly high (70% -100%), but I'm used to that. That (IMO) gives me the the unique voice that I can only get with a G&L bass. I've had good results with my old Hartke 7000/4.5XL, Ampeg B100R, Fender Bassman 400/410, Traynor YBA200/115, and even a Tech 21 Sansamp direct to board. What's new and different is the Genz Benz. This question was aimed at the unique differences in this amp and others.

The amp is not new, but I bought it right here on TB. I'm sure the tube is good, but maybe not OEM. The question was which tubes might give me the best gain and/or volume before distortion.

Lastly, the buzzing Hartke is noisy in my living room ( right next to the Genz that isn't noisy). It was noisy last week at rehearsal. It was noisy at the last two clubs I played. I've checked/changed power cords, speaker cords, instrument cords, tried different speaker cabs. The ground lift switch does not change the "volume" of the buzz, more like the "pitch".

[hasbeen]

G&L pre's are very hot...as are the pups. If you're running it at 70 to 100% plus, you're boosting frequencies, that will hit the front end of most, modern, high-end amps very hard.

You shouldn't have to runt the volume that high for "that tone", you speak of. One point of on-board pres is so you don't lose tone when you roll off or run long leads.

BTW, this is a common issue with Spectors and Bongos as well....not just the G&L. Also, do you have a trim pot inside the pre of the G&L? Lastly, tell me what ALL your settings are....for both bass and amp, and I'll get you squared away.

[coop]

Thanks hasbeen!

This is part of the legendary Customer service that steered me to GB in the 1st place. I'll get some more details to you tomorrow or Monday.

Right now I'm heading out to sit in for a comrade who got zapped by the flu !

[Ken Baker]

Originally Posted by hasbeen

Also, do you have a trim pot inside the pre of the G&L?

No trimmer. The G&L preamp is very simple and its primary task seems to be to allow long cables via impedance change. When in circuit it does increase gain a little, but not as much as you'd think. The G&L's are just plain beasts - active or passive.


http://www.bassesbyleo.com/images/l-...amp/pretop.jpg

Ken...

[hasbeen]

Originally Posted by Ken Baker

No trimmer. The G&L preamp is very simple and its primary task seems to be to allow long cables via impedance change. When in circuit it does increase gain a little, but not as much as you'd think. The G&L's are just plain beasts - active or passive.


http://www.bassesbyleo.com/images/l-...amp/pretop.jpg

Ken...

It does seem pretty straig forward.....doesn't it? I have a fretless JB2 that is passive, who's pups have higher output than most of my active basses. .....the pups a really overwound. Sound good though.

[Ken Baker]

Originally Posted by hasbeen

It does seem pretty straig forward.....doesn't it? I have a fretless JB2 that is passive, who's pups have higher output than most of my active basses. .....the pups a really overwound. Sound good though.

Yup. Very simple due to no EQ. When brought into the circuit, it's inserted between the passive EQ stack & volume control and the jack.

Ken...

[Double Agent]

Originally Posted by hasbeen

BTW, this is a common issue with Spectors and Bongos as well....not just the G&L. Also, do you have a trim pot inside the pre of the G&L? Lastly, tell me what ALL your settings are....for both bass and amp, and I'll get you squared away.

I have a GBE600, which I always run through the tube pre. I'm not sure what the differences are between the GBE pre vs. the Shuttle pre, but I've always just lowered the tube gain if I had too much dirt in my tone and it worked just fine. I've used 3 Spectors and 1 Bongo with this amp and always run my volume wide open, never had a problem.

OP, Roger will get you squared away, but I would definitely lower the gain on the pre is its sounding too dirty, or the preamp volume if you are clipping the power amp. Don't be afraid to use the active pad to help control things, even if you're using a passive bass. A G&L L-series is most definitely not your typical passive bass.

[coop]

Hey thanks for all your suggestions guys. I really appreciate it.

Okay here's what I've got right now:
Shuttle 6.0 -12t Avatar SB112

• Gain = 10:00
• Volume = 12:00
• Low = 2:00
• Mid = 2:00
• Mid Freq = 9:00
• Signal Shape Buttons = Off
• Master Volume = 2:00

Bass: L-2000
Master Volume about 80%
Treble - 40%
Bass - 70%
Both pickups on
Series
Preamp off


I realize that this will change when I get out of my living room and setup with the band, but I gotta start here.

I know this will get sorted out, there's too many players that rave about these amps. It's just new and different, and I haven't found my happy place yet.

Thanks again guys.

[hasbeen]

Originally Posted by coop

Hey thanks for all your suggestions guys. I really appreciate it.

Okay here's what I've got right now:
Shuttle 6.0 -12t Avatar SB112

• Gain = 10:00
• Volume = 12:00
• Low = 2:00
• Mid = 2:00
• Mid Freq = 9:00
• Signal Shape Buttons = Off
• Master Volume = 2:00

Bass: L-2000
Master Volume about 80%
Treble - 40%
Bass - 70%
Both pickups on
Series
Preamp off


I realize that this will change when I get out of my living room and setup with the band, but I gotta start here.

I know this will get sorted out, there's too many players that rave about these amps. It's just new and different, and I haven't found my happy place yet.

Thanks again guys.

thanks for the detailed settings. You are certainly eq'ing very "thoughtfully"...i.e......nothing is "extreme". You're running the volumes kind of high though.

You aren't running out of amp,......you're running out of speaker. The single, low cabinet volume 12", can only move so much air. Plus, you're only putting out 375 watts through it.

Since though, you aren't hearing the volume you want, you turn up the amp. So then, the amp distorts. At this point, most think the amp is giving up when really, it is the limits of the single speaker enclosure.

If you were able to add a an additional cab, you'll find that you can lower the volumes on the amp and it will run cleanly.

[Infernal Affair]

From the looks of it, he's using two 112s, the 12T and an Avatar SB112. I don't think it's a speaker issue.

[Double Agent]

Is the Avatar a Neo or Delta cab? Reason why I ask is that I have a Avatar SB112 Delta and the single driver can almost pull off a small club by itself with only the 275 watts from GBE600. They are pretty mighty little boxes for their size. I have no experience with the Neo version though.

My thinking is this, from where I run my Spector, 12:00 seems a little high for the preamp volume setting unless you are engaging the -15db pad. I would either cut the preamp volume back to 11:00, or engage the -15db pad (I know you are using the G&L in passive mode, but it still has a lot of output. As much, or more, as many active basses), or you could cut your lows and mids back to about 12:30-1:00. Lows require more effort to amplify than mids and highs and you are boosting your lows and lo-mids with a pretty strong signal coming from the preamp already.

You didn't say where you are setting your highs, but let's say you are running them at noon. You could cut your lows and low-mids back to 12:00 or 12:30, and cut your highs down to 10:00 and the sound would be fairly similar IME. Plus, you would wouldn't be asking as much power from the pre section, so might even be able leave the preamp volume where it is.

Just a couple of ideas to try, but Roger definitely is more knowledgeable than anyone else on this board about Genz' products, with the possible exception of agedhorse. They are the reason I own GB gear and likely won't own anything else.

[plankspanker13]

Genz Benz uber alles.

[agedhorse]

I'm not positive I am reading this correctly but if you are using the Shuttle combo with an extension cabinet, it is posssible that the extension cabinet may be wired out of phase with the combo cabinet. If this is the case, adding the second cabinet will reduce the low end performance below that of a single cabinet.

An ease way to check this is to grab an old 9 volt battery, disconnect the speaker from the amp and since the plug is attached, it's easy to connect to the 9 volt battery terminals. Touch the top to the + terminal and the sleeve to the - terminal (it's usually identified on the side of the battery case) the cone should move out. Do this with each speaker. If one cone moves out and the other moves in, you have found your problem.

This is something EVERYBODY playing multiple cabinets should do by the way, mistakes get made, not all speakers are marked according to this convention, and sometimes repairs get botched up. AND, it's not the absolute phase butthe relative phase... ie. both speakers should move in the same diorection. This is especially true specifically with older JBL drivers as they used the opposite standard until about 15 years ago.

[coop]

Okay so here's an update: I did a little more searching and came up with this thread GB Shuttle 6.0 Tube Swap - done it/do it? ( don't know why I missed that earlier, maybe I put in the wrong search terms). So here's what I 've come up with for me the best sounding tube is a JJ CC803S. Also, the best sounding cab combo is the Avatar 112 ( the older rear ported more compact model), and a generic 115 cab I bought for an emergency a couple of years ago. The Genz 112/Avatar 112 combo still seems harsh IMO. Not nearly as harsh as the Hartke 4.5XL however.This is all in my living room with just me making any noise.

I'll know more after Saturday when I get it set up and the drummer starts pounding his snare, the guitard cranks his Mesa 100watt 212, and the nicotine laden cloud seems to hang in the air like a morning fog on some Scottish loch .

[El Tookay]

The stock tube in my Shuttle 6.0 is/ was a Ruby, and, yes, it did get changed out for a JJ ECC83S, just because that tube does a lot of things well with G&L's. From your posted settings, I don't see anything that would freak out the amp. I like to run my preamp gain as hot as possible without losing the bottom end clarity, max the preamp volume and season to taste with the EQ, but usually near flat, or with a bit of cut in the 600hz range. The only time I get the red light on the pre to pin is if I'm using my '84 in series / active with it's inherent E- circuit over-the-top bass boost. It's quite unlikely that the bass would be acting up, especially in passive- try changing the tube. Check impedances, and try a different cabinet (although, that might fuel GAS...).

Been gigging and loving my Shuttle for almost a year now, and haven't had a problem with it ever. Hope it works out, Coop, GB and G&L is one mean, righteous combination....

[agedhorse]

coop, did you try my suggestions? Changing the tube isn't going to make the kind of difference your first post mentions.

[coop]

Agedhorse,

I checked all of the cabinets, (except the 12t). All of the speakers move out towards the grill when I do the 9volt battery test. Is there an easy way to do this test on the shuttle cab?

Thanks,
David

[agedhorse]

Originally Posted by coop

Agedhorse,

I checked all of the cabinets, (except the 12t). All of the speakers move out towards the grill when I do the 9volt battery test. Is there an easy way to do this test on the shuttle cab?

Thanks,
David

You need a NL-4 to 1/4" cable to do it easily.

So far, you haven't uncovered the problem I suspected.