New Roadster sounds like crap

[glennhue56]

Against my better judgement, and what I had heard/read, I bought a new Roadster and cab.

Signal chain: guitar (Ibanez or LP, which are both noiseless in my other set ups) to Digitech GSP1101 (set on #7 to bypass the processor preamp/amp modeling) using the 4 cable method with the Roadster head. Everything (inlcuding Roadster) is plugged into a Furnman power conditioner that draws from grounded outlet.

The amp hums/buzzes. All the time. AND I'm getting a radio station. Have eliminated all other rack components (ISP Deci. Rack G, wireless, etc.) to attempt to isolate the problem. The fix, which isn't really, is turn the gain OFF on the Digitech (or chose a patch w/no gain), and roll gain and presence way back on the Roadster. The result is nice tone for, say, a cover of Breezin', but good for little else. The Digitech was noiseless when used with my Peavy solid-state amp.

So now I've spent a decent amount of money on an amp/cab, hours trying to get it to work with an effects unit, and for my gig this weekend (and probably for the one on the 23rd), I'm going to have to throw my old rig back together.

I'm going to call Mesa this a.m., but wondered if any of the tinker-ers on the board may have any insight. Besides the insight that those amp-modeling folks might just know something that the rest of us refuse to accept! Thanks so much.

 

[Geiri]

That's funny

When I had a stilletto I got a gsp-1101 and my amp went bonkers ?????? Everything else was fine in the loop, I had previously used a tc g-system, a tc g-sharp and line6 pod xt. All of these worked seamlessly in the loop of the stiletto but as soon as I plugged the gsp-1101 into it it started behaving in a similar way as you describe. Humming like a mothereffer and no matter how I set the gsp-1101. I used the 4cm and walked through the setup several times before I gave up and returned the digitech thang. And this was no faulty cable or anything such because I used the same cables to for instance to hook up my pod, verbzilla, echopark and the g-system.

I think maby digitech hates mesa for some reason :mrgreen: :mrgreen:

Just return the gsp and get yourself a cheap boss gt 8

 

[Scary]

If it happens when using the amp alone bother Mesa. Otherwise it's probably not the amp.

 

[KH Guitar Freak]

Perhaps it would be better to check the valves first, especially the preamp valves???

 

[kiff]

using the 4 cable method with the Roadster head.

have you tried unplugging it from the effects loop and just running it in front of the amp w/ gain?

 

[glennhue56]

Thanks guys. I'll put it in front of the amp tonight, as well as (eeyewww) bypassing the amp preamp and using the processors preamp to see what happens. Hard to fathom that it could be tubes after only a few hours of playing (trying to get it to work), but Digitech incompatibilty may be more likely. I'll keep tinkering.

 

[kiff]

the reason I asked, in case you don't already know, is that it's possible the 4 cable method is causing a ground loop. that would cause a hum, but I'm not sure (kind of doubt) it could cause radio station interference.

if it does happen to fix it, then you might be able to use ground lifted cables (disconnect the shielding on one end) for the effects loop.

 

[KH Guitar Freak]

Thanks guys. I'll put it in front of the amp tonight, as well as (eeyewww) bypassing the amp preamp and using the processors preamp to see what happens. Hard to fathom that it could be tubes after only a few hours of playing (trying to get it to work), but Digitech incompatibilty may be more likely. I'll keep tinkering.

Well, only saying as one or more of the valves could have been damaged on the way to the store. Just saying. Checking them isn't too hard though, hence I also suggested this method amongst the few suggestions that have been made in this thread...

 

[b0nkersx]

Bypass the loop from the back panel and run straight into the amplifier from your guitar. If you have noise, it's the amp (maybe a tube problem) or your guitar or cable (you have two guitars and probably more than one cable so it should be easy to determine if its either of the latter two). If this is successful in eliminating noise, then turn the loop on, but don't plug anything into it. If you still don't have any noise, then it's the effects unit. If you have noise after turning the loop on (with nothing plugged in), it's an effects loop issue.

Also check your speaker cable. Make sure you didn't use an instrument cable to go from head to cab.

It's extremely unlikely that Mesa would send out a head that's getting RF noise.

 

[ibanez4life SZ!]

Since you mentioned 4 cable method, I've got a hunch you're experiencing a ground loop.

 

[glennhue56]

Roadster plugged into grounded power strip, plugged into grounded outlet (GFI).

Guitar only plugged into front = good tone, only slight hum/buzz (probably normal for this brand/amp).

ANY effect or processor* between the guitar and the front end (or in effects loop) increases the hum/buzz AND adds radio transmissions. Doesn't matter if the effect or processor is plugged into the same power strip, or even plugged in at all. Swapping guitars, cables, power strips, etc. has no effect....it's a $2,000 radio.

Didn't contact Mesa yesterday, as I thought there were still some more things to try/hours to spend, but I am out of options. Thanks for all your suggestions; definately a case of buyers remorse.


* Separately tried Digitech GSP1101, Digitech 2120, MXR Graph Equal, ISP Decimator, etc.

 

[b0nkersx]

Roadster plugged into grounded power strip, plugged into grounded outlet (GFI).

Guitar only plugged into front = good tone, only slight hum/buzz (probably normal for this brand/amp).

ANY effect or processor* between the guitar and the front end (or in effects loop) increases the hum/buzz AND adds radio transmissions. Doesn't matter if the effect or processor is plugged into the same power strip, or even plugged in at all. Swapping guitars, cables, power strips, etc. has no effect....it's a $2,000 radio.

Didn't contact Mesa yesterday, as I thought there were still some more things to try/hours to spend, but I am out of options. Thanks for all your suggestions; definately a case of buyers remorse.


* Separately tried Digitech GSP1101, Digitech 2120, MXR Graph Equal, ISP Decimator, etc.

Try hard-bypassing the loop. One of those tubes might be microphonic. Your issue isn't "normal" at all (what I mean is that it's not a problem with the amp design, it's a problem with your amp).

 

[Heritage Softail]

I would make sure you have a solid connection to ground for all of your gear. It may be an internal ground or grounding resistor has popped loose. Just curious, are you near an airport? I lived near an Air Force Base and er would pickup pilot transmissions on occasion. Issues we cleared with grounding and shielding.

 

[Murphy Slaw]

That's funny
I think maby digitech hates mesa for some reason :mrgreen: :mrgreen:

Bwahahahahahahaha.....

 

[SteveO]

I have run my GSP 1101 in 4 cable with an Express, a Roadster head, and a Mark V head with no problems, so it's not something in the design of the 1101 or the amps. RF interference typically comes in at the guitar-level signal, so I would be checking everything that is going before the guitar input on the Mesa.

 

[madryan]

I'm betting ground loop. I'm also betting it's a cable issue as well. I've had cables that picked up radio stations before so what sort of cables are you using? Are they good cables like Mogami or are they crap cables like Monster?

 

[jlomonac]

lol i get the same problem, background noice/radio. i use a timefactor (fx loop) and a TS9 (up front), i haven't tried anything yet though. i do have one cheap cable in the loop, the rest are all planet waves. also, whats this 4 cable connection that you guys speak of? im interested xD

 

[Dolebludger]

Every time I have picked up a radio station on my amp, it has been because there was a short in the guitar hook-up cable, or one of the between-effects cables. Might be sorth a check-out, because it would be a cheap fix.

 

[glennhue56]

Thanks everyone; regional Mesa rep. is checking it out. Appears to be some issue in the effects loop of the amp (even w/nothing plugged into it), as doing the hard bypass (via the switch in the back) takes care of it. Will let you know ultimate resolution, if it may help others.