Matrix GT1000FX channel drop out issue.

BC_GTR

BC_GTR

Member
I just purchased a GT1000FX to use with my Axe FX lll and had channel "A" drop out after just a minutes of playing. I am using a custom Mesa 4x12 cab that I filled with 2 of the Celestion F12-X200 and 2 Celestion F12M-150 Full Range speakers. Both speakers are 8 ohm. (measured with ohm meter at 6.6 ohms) Running cab in stereo and should be a 4 ohm load on both sides of the amp. (measures 3.3 ohms on meter) When the amp started acting up I called the number for Matrix USA and spoke directly to the owner and designer of the GT1000FX amp, Andrew Hunt. He asked several questions and decided that the amp was being exposed to an impedance issue. He stated that he had never run across one side of the amp dropping out before. and was quite curious about my setup. I am wondering if anyone out here has had a similar issue. Not real fond of wiring the speakers in series though it would eliminate the low impedance issue... thoughts....
 
If the load is the same on both channels, and only one channel is cutting out, it stands to reason that something's up with that channel. Unless there's a dodgy speaker or speaker wiring. Do you have another amp to try the cab with? I assume you verified there's signal out of both Axe channels, or to the input of the Matrix, at the time something was cutting out, yes?
 
I have the 2U gt1000fx and have run it in stereo to different impedance cabs (8 ohm and 16 ohm) with no problems. Needed to be very careful with the rear settings as I think it was easy to setup as mono bridged or dual mono rather than separate stereo pathways.
 
Need to make sure that each side of the cabs speakers are totally isolated from each other. No common grounds or anything else that can link or short the outputs of the amp. We've seen ill fitting jack sockets lose connection also due to sound pressure levels inside cabs. Certainly try the affected channel on it's own (stereo mode on amp and single lead into amp and single channel out to cab) and see if the suspected channel still does it. Also switch cables etc just in case.
 
Dave Merrill said:
If the load is the same on both channels, and only one channel is cutting out, it stands to reason that something's up with that channel. Unless there's a dodgy speaker or speaker wiring. Do you have another amp to try the cab with? I assume you verified there's signal out of both Axe channels, or to the input of the Matrix, at the time something was cutting out, yes?
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I have been using both a Crown XLS1000 and my Mesa 2:90 and no issues with either one. Signal verified and balanced. I bought this amp to get closer to the Mesa response without the weight.
 
Lightningboy said:
Need to make sure that each side of the cabs speakers are totally isolated from each other. No common grounds or anything else that can link or short the outputs of the amp. We've seen ill fitting jack sockets lose connection also due to sound pressure levels inside cabs. Certainly try the affected channel on it's own (stereo mode on amp and single lead into amp and single channel out to cab) and see if the suspected channel still does it. Also switch cables etc just in case.
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I replaced the 1/4" jacks with Neutrik 2 pole connectors no cross-talk between any of the poles. Matrix is replacing the amp after having gone through all of these issues over the phone with Andrew and opening up the amp and sending him pictures of everything. I will say that talking to the actual creator of the amp and having someone that knows every possibility of what might happen is quite refreshing. At any rate I was just curious if anyone else has had any issues like this.
 
So after having the replacement amp for only 2 months, this morning it did not power up at all. I used it last night at home practicing for an upcoming gig and worked fine. This morning nothing. Checked the fuse on the power-in and it's seems to be good. Back to the drawing board with Matrix. I have talked to several artists that use this amp with their rig and they have had no issues. However the amps they have are UK built and 1U versions. Mine is USA built and a 2U. Shouldn't make a difference but there you have it.
 
I’ve been using the 2U version to run 2 Xitones or a Mesa Traditional 412 (Stereo) with no issue.
 
Just got off the phone with Andy Hunt (designer/owner) Matrix Amplification USA. Turns out the power supply failed. Sending it back for a new unit.
 
BC_GTR said:
Just got off the phone with Andy Hunt (designer/owner) Matrix Amplification USA. Turns out the power supply failed. Sending it back for a new unit.
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Unfortunately, no vendor can control the quality of 3rd party parts included in their builds - regardless of product. They "assume" as certain quality based on the supplier, but bad parts DO happen. At least they are taking care of you!
 
Man sorry to hear about your bad luck with units. Fantastic you were able to speak directly with the man. Hoping your next unit is rock solid. I bought a single space used and while I was at it found the most common part that fails in them based on what I read on line to have on hand just in case. I had a dropout issue at one gig, could have been bad cable or just a power brown out being we had a lot of draw on one outlet. In a panic I bought a Seymour Duncan Powerestage 700 that I used for a few month till I decided to plug the Matrix in and see if it still had an issue. Turns out the Matrix was fine and I went back to that. Xitone passive wedges for info sake.
 
Sounds like matrix has stellar customer service. Probably just bad luck man...it happens. I'd love to have a matrix amp but my cheap Behringer epx4000 freaking rocks the F12s so I can't justify a matrix to the wife. Lol
 
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