Triaxis Output Volume Pot Issue

[Mandarine]

Wanted to get some ideas on this subject. I run a Triaxis/ 2:90 setup. The Triaxis' output pot has a very limited useful range. From 0 to 1 gain goes from nothing to loud. From 1 to 3 volume goes from Loud to VERY LOUD. From 3 to 10 there is no noticable volume increase. This makes finding a sweetspot in the live mix very difficult.

After talking to Mesa they said that the pot is a linear taper and no one else has complained. I have been looking for a replacement 25k, stereo pot, co-centric with an audio taper to no avail. Another option might be to insert a compressor between the Triaxis anf the 2:90 that allows finer gain adjustment. Or, the replacement of the two mono 250k pots on the 2:90.

Anyone have issues with this?

 

[Marvell]

Hi Mandarine, in my triaxis the output knobs start at 1. From 0 to 1 nothing, from 1 to 10 it goes linear from normal to very loud. I've also the 2:90 and in between a g-major.

Anto

 

[disassembled]

You probably have a dirty/faulty pot and need to replace it. If it's under warranty then it should be done for free otherwise you will have to change it yourself. It's pretty easy (just three wires) and shouldn't take more than 15 minutes depending on your skill with a soldering iron.



Greg

 

[Mandarine]

Marvell:

Do you find that from 1 to 10 the loudness increases in a gradual slope? I want to use "linear" but that is a taper for potentiometers as well as a description of gradual loudness increase. If gradual is indeed the case, then I must have something wrong with the control becasue when I go from 1 to 3 it "jumps" in loudness and I cannot find a sweet spot. A "hair" increase is too loud and a "hair" decrease is to quiet. From 3 to 10 the loudness never increases.

 

[Marvell]

mine from 1 to 10 increase gradually. Replace the pot by yourself or buy it and go to a tv/audio tech for the installation. They make a professional soldering, clean and in a few minutes :wink:



anto

 

[Mandarine]

After much investigation (and parts ordering) I have discovered a couple of things for all you Triaxis/ 2:90 users. The Output volume pot on the Triaxis is indeed a 25k ohm Linear Taper. Why in the world Mesa would engineer it this way is beyond me. The only thing I can think of is they couldn't find a manufacturer of a 25k stereo, Log taper pot - I sure couldn't find one on the internet to replace it. I ordered a replacement from Mesa thinking I got a "weird" Triaxis with a linear pot, but the replacement is the same linear taper.

What it means is that the volume level will "jump" in the lower range of the pot and will be virtually ineffective in it's upper range at controlling loudness. SO - next step. I investigated the input level controls of the 2:90. They are 250k mono pots but have an audio taper. The weird thing however is how they are wired. One end of the pot is grounded and the wiper is connected to both the 1st stage output and the 2nd stage input. The third terminal of the pot is not connected. I made a modification to the way the pot is wired, taking the 1st stage and wiring it to the unused terminal 250k away from the ground, and left the input to the 2nd stage on the wiper.

This has achieved a much better fine-grain control over the volume ouput of the rig. I still cannot use the Triaxis output control to much effect so I leave it a 50% and use the input control of the 2:90 to fine-tune my volume output.

I had also been in contact with Bob at Eurotubes.com who suggested a lower output preamp tube that would "tame" the beast a bit. I would also like to try that as well.

Bottom line I guess is that I can't believe that other people haven't experienced this issue... does everyone just run this Triaxis/ 2:90 full open all the time?