Genz Benz Shuttle 6.0 Issues... Help?

[Dave-in-TN]

I just barely acquired a Shuttle 6.0 that's about 6 months old in a trade. It seems like a great little amp, but I have two issues/questions I need help with...

Issue #1:
No matter how high I turn up the Gain knob on the preamp, the "overload" light never comes on, and I don't hear any noticeable change in tone. Any ideas? I'm using a passive Peavey Millenium BXP 5-string.

Issue #2:
When I first hooked it up to my cab (BFM DR250) and my bass and powered it on, to my horror, it immediately went into "protect" mode. I then shut it off for a second and turned it back on. It seemed OK, and I played for about 10 seconds, and the protection mode kicked in again. After that, I tried at least a dozen more times alternating between speakons on the back of the amp. No luck!

Just when I was getting real worried, I decided to get out another cable and try it. The cable I had been using was 1/4"-to-1/4" speaker cable with 1/4"-to-speakon adapters on both ends (that just happened to be the one that I had handy when I first plugged everything in). The next cable I tried was a regular 20' speakon-to-speakon cable. I hooked it up, and everything seems to work fine.

A couple of things puzzle me about this situation. First, the cable that was giving me problems has been used quite a bit before, and has never given me problems using the same cab with other amps. Second, the problem cable worked one time for a few seconds. And finally, I was searching here on TB, and found this thread where a guy had a similar problem.

Any thoughts? I just want to know whether or not this amp is OK or whether it needs servicing. If it does need servicing, is there any hope for warranty coverage on a less-than-year old amp if I can get proof-of-purchase info from the original owner?

Thanks. I'm looking forward to being a happy member of the GB family!

 

[hasbeen]

in that thread, the problem was with his cabinet....the crossover to be specific.

Your amp is under warranty...eventhough you bought it used.

Please call the shop: 480.941.0705. Describe the issue and let them know you're from TB.

 

[cheezewiz]

Well, if using a new cable ended the problem, i'd say problem solved.


As far as the gain, apparently your bass just put out a very strong signal. I use a passive Dingwall Afterburner with my Shuttle 6.0, and it only lights up on heavily plucked notes on the low E or B.

 

[svtb15]

Im sure someone from GB will be here soon to answer your warranty question.
EDIT.. I dont type fast enough

Your Peavey may not have enough output from the passive pickups to drive the front end of the amp to get it to distort.. A bass with that low output may need an additional preamp to get more gain....

My initial reactions is The speaker cable problem seems be exactly that.. a cable problem..

if the amp worked for one second then kicks off when you play it it, it is because the amp when sending power to the speaker cab senses a current overload (short ) and engages the protect to keep the amp from frying.. its supposed to do that...

even if it did not do it on your other amp does not mean the cable is not at fault if your amp was not a class D output...... I would check the cable with DVM in the low Ohms setting using test point s from hot to ground not plugged into anything..... that will show you if you have a short in the cable itself..it should read open or no resistance... if you see any change your cable has a short somewhere and needs to be fixed or replaced.

 

[Dave-in-TN]

in that thread, the problem was with his cabinet....the crossover to be specific.

Your amp is under warranty...eventhough you bought it used.

Please call the shop: 480.941.0705. Describe the issue and let them know you're from TB.

Thanks, hasbeen. I'll call. It may be that there is no issue, but I'd rather confirm that with you experts!

 

[Dave-in-TN]

As far as the gain, apparently your bass just put out a very strong signal. I use a passive Dingwall Afterburner with my Shuttle 6.0, and it only lights up on heavily plucked notes on the low E or B.

So you only overdrive the preamp with heavy E's and B's even when the gain is turned all the way up?

BTW, how do you like your Dingwall/Shuttle combination? Once the Combustion comes out, I hope to join the Dingwall family also!

 

[cheezewiz]

So you only overdrive the preamp with heavy E's and B's even when the gain is turned all the way up?

BTW, how do you like your Dingwall/Shuttle combination? Once the Combustion comes out, I hope to join the Dingwall family also!

Yep...exactly. Passive basses just don't put out that strong of a signal. I love the Dingwall Shuttle combination. The Dingwall is so clear sounding from Low B on up, and the shuttle really brings that clarity out, but without sounding sterile.

 

[Dave-in-TN]

Your Peavey may not have enough output from the passive pickups to drive the front end of the amp to get it to distort.. A bass with that low output may need an additional preamp to get more gain....

Thanks.

My initial reactions is The speaker cable problem seems be exactly that.. a cable problem..

You're probably right, but I have tested it with a cable tester (without the speakon adapters), and it shows no shorts. Also checked it with a multimeter (both with and without the speakon adapters), and the resistance fluctuates between 0.1 and 0.5 ohms.

 

[Rick Auricchio]

And I presume you've checked between the two conductors to verify that there is no connection between them (i.e. a short).

You're sure the crossover in the DR250 is properly wired?

 

[svtb15]

dont check through the cable ie. Tip to Tip or Sleeve to Sleeve.. that will only give the impedance of the cable through its length.. ..we need to detect a for a possible short.

Do this...... check Tip to Sleeve without the other end being plugged into anything..
that way you will see if you get a short in the cable its self.. its can be as simple as one strand of the pair is touching the other contact in the connector .. also is your speak-on a (+1 -1 )type.

if you have done that already then you should be good.

Thanks.


You're probably right, but I have tested it with a cable tester (without the speakon adapters), and it shows no shorts. Also checked it with a multimeter (both with and without the speakon adapters), and the resistance fluctuates between 0.1 and 0.5 ohms.

 

[hasbeen]

dont check through the cable ie. Tip to Tip or Sleeve to Sleeve.. that will only give the impedance of the cable through its length.. ..we need to detect a for a possible short.

Do this...... check Tip to Sleeve without the other end being plugged into anything..
that way you will see if you get a short in the cable its self.. its can be as simple as one strand of the pair is touching the other contact in the connector .. also is your speak-on a (+1 -1 )type.

if you have done that already then you should be good.

thanks for your help with this Kirk.

 

[Dave-in-TN]

dont check through the cable ie. Tip to Tip or Sleeve to Sleeve.. that will only give the impedance of the cable through its length.. ..we need to detect a for a possible short.

Isn't that what a cable tester does? I've already tested it with one of these, but I will try it again using the tip-to-sleeve test with the multimeter. I'll report back later tonight.

also is your speak-on a (+1 -1 )type.

It's a 1/4"-to-1/4" with [Invalid or Expired Link Removed] on both ends.

 

[Dave-in-TN]

Checked the cable again with the multimeter. Tip-to-sleeve on both sides. No shorts. Also tested with the adapters connected to the cable. No shorts. What else could be causing this particular cable to either be the cause or trigger the cause of the problem?

 

[Rick Auricchio]

Yeah, the Behringer cable tester (an apparent clone of the Swizz Army unit I have) will test for shorts in the cable.

When testing, you should wiggle the cable to verify there aren't momentary shorts or opens inside the jacks, or a partial break along the cable.

A short would definitely trigger the amp's protect mode. An open circuit would simply remove the speaker load, which in itself wouldn't force protect. But suppose the open is intermittent: the load comes and goes several times in quick succession. In that case, it may be possible that the protection circuitry would react to the yes/no/yes/no speaker load.

 

[Dave-in-TN]

Yeah, the Behringer cable tester (an apparent clone of the Swizz Army unit I have) will test for shorts in the cable.

When testing, you should wiggle the cable to verify there aren't momentary shorts or opens inside the jacks, or a partial break along the cable.

Did that. No signs of shorts or opens, intermittent or otherwise.

 

[Red Planet]

I know I'm Mr Fancy Pants with my cables and all but I would not use an adapter you speak of, too many things go wrong with adapters IMO IME.

If the amp is functioning fine with the SO to SO I would just give her a good workout and see how she performs. If the amp should go into protect again with a Spen On Cable then I'd be calling for help.

 

[Dave-in-TN]

I know I'm Mr Fancy Pants with my cables and all but I would not use an adapter you speak of, too many things go wrong with adapters IMO IME.

If the amp is functioning fine with the SO to SO I would just give her a good workout and see how she performs. If the amp should go into protect again with a Spen On Cable then I'd be calling for help.

I'm with you. The only reason I used the cable with the adapters in the first place is because it happened to be the shortest length one I had on hand when I was first hooking up the amp to try it out. I didn't intend to use it long term. But, when all this weird stuff started happening, I started searching for an explanation just to be sure there wasn't an issue with the amp itself. Although it seems like this one cable may have an issue, I haven't yet been able to prove that despite all my testing which leaves a lingering doubt in the back of my mind. But, I have been using the amp with another speakon cable since then, and it has worked fine. It seems that "strange things are afoot at the Circle K."

 

[agedhorse]

I know I'm Mr Fancy Pants with my cables and all but I would not use an adapter you speak of, too many things go wrong with adapters IMO IME.

If the amp is functioning fine with the SO to SO I would just give her a good workout and see how she performs. If the amp should go into protect again with a Spen On Cable then I'd be calling for help.

This is exactly what I wiould suspect first. If the 1/4" plug is not fully inserted, there exists a possible short circuit condition between tip and sleeve. This is (one reason) why we have been phasing out 1/4" connections, they are responsible for an awful lot of amplifier "problems" that have nothing to do with the amplifier.

The second thing I would suspect is a possible wiring problem with the speaker, maybe the jack twisted around, twisting the wires and causing a short. Could be an intermittent or loose part on the crossover too.

Regarding the inability to get the O/L LED to light at maximum gain, do you have the bass's volume all the way up? The other possibility is that it has naturally low output level and in that case IF you want to overdrive the tube, you will need a booster or preamp pedal with your particular bass. If you have adequate output volume and acceptable tone for your application, there is absolutely nothing wrong with operating it as you are now. You are still getting tube coloration, just not the additional overdrive and distortion.

 

[Dave-in-TN]

This is exactly what I wiould suspect first. If the 1/4" plug is not fully inserted, there exists a possible short circuit condition between tip and sleeve. This is (one reason) why we have been phasing out 1/4" connections, they are responsible for an awful lot of amplifier "problems" that have nothing to do with the amplifier.

The second thing I would suspect is a possible wiring problem with the speaker, maybe the jack twisted around, twisting the wires and causing a short. Could be an intermittent or loose part on the crossover too.

Both of these seems like logical possibilities, but, in both cases I would have thought that there would be some sort of indication that there was a problem using other amps as well. The fact is, however, that both the speaker and the cable have functioned (and continue to function) without issue when connected to my my current Crown XTi-4000 power amp as well the QSC PLX 1104 power amp I owned before that.

 

[Red Planet]

Some amps due to their topology are more sensitive to a problematic cable. I would not use a 1/4 adapter of any sort with this amp.

Also I have a heavy duty speaker cable I bout from a local Tech that had big 1/4 ends for my guitar rig. The day I got it home hooked it up and it would short. I read it with a meter nine ways from heck and could not find a problem. However it was obvious the cable was the issue. I took it back and he said he fixed it. I hooked it back up and same problem. I hooked to another amp and it worked. Go figure. That cable has bad mojo or something. The cable is somehow bad/intermittent and only malfunctions with the one amp but at this point I am not going to be blowing my amp up to figure out why. I put it in the trash.