Triaxis&2/90 Issue

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keithl

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I have a new to me Triaxis&2/90. Triaxis is a year old; 2/90 is older with tubes of an undetermined age.

A few times when I switch the triaxis to factory preset 4 and 5 (clean sounds) the volume will be a fraction of the
previous preset's volume and will then increase by itself (along with a hum sometimes) after a minute or so.
Volume increase on it's own, sometimes gradually, sometimes more suddenly.

This is after the 2/90 is warmed up and I have only noticed this happening on presets 4 and 5 and not every time.

Any ideas? Thanks
 
Old BF Shred said:
Try the Triaxis with a different amp; try the 2:90 with a diff preamp and see what the problem follows...
Click to expand...

Looks like it's the Triaxis. Green and Yellow rhythm channels not working correctly. Tried new tubes, didn't work. Going to have to send it off for repair.
 
I had bad ribbon cables in my Triaxis, which I replaced to solve, for lack of a better description, "whimpy tone".

But it was not intermittent or changed volume as you describe. Still they could be starting to go esp if yours is an older Tri (mine is a very early model).

Also there are Tantalum caps that can over heat and start turning dark, and I found one that I also replaced, but I am not sure it was really causing a noticeable problem. It was likely more preventative.

I also had bad plate resistors (both of them, actually) on, IIRC, V4 12ax7 stage (may have been V5...it's been a while). This is known to plague some of the older units, as well.
Last but not least, I have heard that the LDR's, used to isolate stages in the circuit, can and do go bad and can cause similar symptoms.
I have had no issues with mine (so far).


Please let us know what they found, once you get it back.

Good luck! :)
 
Will do, thanks.

Old BF Shred said:
I had bad ribbon cables in my Triaxis, which I replaced to solve, for lack of a better description, "whimpy tone".

But it was not intermittent or changed volume as you describe. Still they could be starting to go esp if yours is an older Tri (mine is a very early model).

Also there are Tantalum caps that can over heat and start turning dark, and I found one that I also replaced, but I am not sure it was really causing a noticeable problem. It was likely more preventative.

I also had bad plate resistors (both of them, actually) on, IIRC, V4 12ax7 stage (may have been V5...it's been a while). This is known to plague some of the older units, as well.
Last but not least, I have heard that the LDR's, used to isolate stages in the circuit, can and do go bad and can cause similar symptoms.
I have had no issues with mine (so far).


Please let us know what they found, once you get it back.

Good luck! :)
Click to expand...
 
Will do, thanks.

Old BF Shred said:
I had bad ribbon cables in my Triaxis, which I replaced to solve, for lack of a better description, "whimpy tone".

But it was not intermittent or changed volume as you describe. Still they could be starting to go esp if yours is an older Tri (mine is a very early model).

Also there are Tantalum caps that can over heat and start turning dark, and I found one that I also replaced, but I am not sure it was really causing a noticeable problem. It was likely more preventative.

I also had bad plate resistors (both of them, actually) on, IIRC, V4 12ax7 stage (may have been V5...it's been a while). This is known to plague some of the older units, as well.
Last but not least, I have heard that the LDR's, used to isolate stages in the circuit, can and do go bad and can cause similar symptoms.
I have had no issues with mine (so far).


Please let us know what they found, once you get it back.

Good luck! :)
Click to expand...
 
Turns out the main thing that was wrong was that 3 Switch Capacitors were shorted out. They replaced those and three others as a precaution and the output Pot.
 

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