triaxis with gsp 1101 diagnostics

[batman]

I have mesa triaxis 2.0 manufactured late 2002 running on jj tesla eec83s tubes and most interesting things happen recently few weeks after I purchased new effect for my system. First 3 weeks my system was a working amazingly.

My rig is simple : guitar - gsp 1101 in - preamp loop out - triaxis - gsp 1101 peamp loop in - gsp main out - bbe 482 sonic maximazer - vht 2:90:2


I have following problem:

My rig gets a lot of hum (like ocean humming) when i use clean sounds (Triaxis artist preset petrucci crystal clean) ( GREEN clean channel) and run my quitar signal through the gsp 1101 front section. There is no hum when plugged direct to triaxis with same clean setup. Hum is so loud that my bbe reads -6 db constant signal.

There is NO problem using distorted sounds. I use mark 4 crunch (lead 2 yellow) and recto lead (lead 1 red ) setups a lot. There is NO significant difference in noise plugging in to gsp or direct to triaxis with those sounds. No need for noise gate even in high gain.



The funny things:

1. Clean sounds that have hum , do have hum in all gsp set ups. Of course high compression will make it more audible. None of the gsp presets used with clean and humming presets hum with different distorted preset.

2. In a humming preset (petrucci crystal clean) setting a dynamic voice from 0 to 1 (one step) will eliminate a lot of hum. (cut it to half)

3. I use triaxis program numbers 21 and 22 for my clean sounds. 21 is lower gain petrucci clean preset on rhy green channel and it has more hum than 22 which uses rhy yellow with more gain. Both have no dynamic voice and funny thing 2 happens on both. Hum is present when gain is low and master is high

Recently, during these diagnostics, all triaxis tubes were changed twice, I also changed all cables to new ones, then they were changed to new and balanced. Then i changed the GSP 1101 to new model (revision B) to make sure there is no loop issues build in.

My conclusions:

I think my problem might be related to to either level of the loop or ground issues. Ground issues Are unlikely since the triaxis is running on 110/220 isolation transformer. All other gear is powered by power conditioner and anyway all plugged to same socket.

Loop has only 2 levels in gsp 1101 +4 db and -10 db. so there is not much i can do.

I have a little fear that there might be an op amp something getting too much signal or working too hard.



Pease let me know if there is any help diagnosing this problem or similar expriences or solutions. I have been working on this for guite a long time so any help is really preciated.


Sincerelly,

 

[bro]

i am running a triaixs with a 1101,behringer eq and a mesa 2:100.
I get the same ocean noise on my clean channels.

 

[ned]

It may be a ground loop. A Ebtech hum eliminator will take care of that. Also try using 2 different outlets to see if that takes care of the hum.

You do have the amp models off on the GSP right?

Also try not running anything pre-loop (stomp box, compression) to see if that takes out the hum.

 

[batman]

Bro, same problem. i got some support from digitech but not much help ! just a new firmware to try out and better noise gate with adjustable positioning. here is the link: http://www.mustbebeta.com/

Checked the electrical issues with engineer yesterday and it is nothing related to electrical ground loops or similar. The noice is there even with 1 feet the cable in the digitech loop. loop is better in rev. B gsp:s which has all new converters and board desing. The hum is amplified by effects running in gsp front section with and will not diappear by simply turning effects off.

I can listen to hum with headphones easily. plug 1 feet cable to loop and turn volume to full. the same hiss is amplified with triaxis and gets pretty annoing, there is also too high level. The emplyment of dynamic voice has hum cancelling effect internally in triaxis and has nothing to do with hum generated by the loop.

The tone is pretty well preserved in gsp 1101 recv b. i tihnk it sounds better than old rev a.. i dont experience tone sucking too much. pretty same as using my morley wah on front of triaxis.


will have to try isolation on signal between gsp and triaxis in..... more on that later ....

 

[bro]

I have replaced all cables with planet wave cable kit.Changed from a furman power conditioner to a monster pro 2500.
Replaced all tubes in triaxis.Removed my behringer eq.
I am only running a chorus from the 1101 with my clean patch.
But can be heard most of the time(not all the time).

 

[batman]

Results of the later tests.....

Nothing helps for the hum complitely, no tubes or electrical cables... but in the signal path there is an mistake of engineering somewhere...... running a morley wah or other pedal between without a true bypass ,between gsp loop out and triaxis in helps a lot. Morley in the signal path is 50% less noise and when morley turns on there is no hum at all...

funny

 

[bro]

i just got an email from digitech.They told to run in setup 5.
Then i would lose all the front end effects(wah,distortions).They said the triaxis does not like anything in the front end.
I know many people who run overdrives and distortions infront of there triaxis's.
I am getting close to selling this.Don't want to,just have to.

 

[dass101]

I also have the GSP and the Triaxis, and used the GSP before with another high gain amp.

There is nothing wrong with the TA, I strongly believe that (some) GSPs have noisy circuits in the "send" output.
I got the same white noise using that setup (Wizard 7), and nothing cured that. Right now I am also using only the "post" effects.

I will keep the unit for now, it still sounds pretty good, and probably the only other processor that would do the 4CM right would be the G system, which is much more expensive.

 

[bro]

today they said to change the loop setting from -10 to +4 or from +4 to -10.
What should it be set as?

 

[dass101]

It depends on what TA output you use.
I just came from the rehearsal, and did some checks. If you use the normal output, you have to set the +4/-10 button to +4, otherwise you would have to set the output knob extremely low. If you use the "send" output (to me that sounds slightly better) I would recommend the -10 setting.

I put a hum eliminator (Behringer) between the GSP send and the TA input, and, although there is definitely some noise increase, it is manageable, and the benefits of using the GSP in 4CM out weight this.

I did notice something else though, after intensive A/B testing. Even if I make a patch with nothing in it, it sounds different with the patch on than in bypass. In bypass the sound is a bit smoother, with the patch on it is a bit edgier (not necessary in a good way)