Jackie's mini tube roll

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Jackie

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I had some spare time today so I decided to tube roll my TriAxis to see what I could squeeze out.

Sorry if this isn't really comprehensive, sadly I only had Shuguang 12AX7, TungSol 12AX7 and JJ ECC83S to choose from (no EH was really interested in that). And I only had time for Lead 1 Input and Lead 2 Input (V1 and V4 positions). Will do the rest occasionally.

V1
Here I was primarily looking for more clarity, in any form or shape, and a little less fizz. A

I had in a Mesa branded 12AX7WA Sovtek tube. I swapped it and the TungSol 12AX7 around, then I threw in a JJ just for fun, then a Shuguang.

I found the TungSol to clean it up nicely and add some silk to the midrange and some bite to the top end (it being a bit more musical than the thin top I got on my Marshall using Tungs). Bass was also more usable and low end more firm. This is what I got in the end.

The JJ was nice, but I didn't like the extra "blur" in the mids I got, also the top end was a bit subdued and there was a bit more bass than I'd like. While it wasn't a bad tone it certainly didn't help my cause.

The Shuguang was similar to the TungSol but with a little less clarity that stepped aside for a little "grain" in the tone, though the low end was nice and crisp. So it was good but the TungSol did a better job for what I wanted.

V4
Here I didn't really know what I wanted, I just know the tone is a little lifeless and I wanted it to be a bit less dry.

Here I didn't put in the TungSol because I only had one tube and I used it for V1, so I didn't want to touch it even though common sense told me I could.

First I tried was the Shuguang 12AX7 and this thing RIPPED MY FUKING FACE OFF!!! I put it in, fired it up and said "holy mids!!!", it was very aggressive, bright and downright nasty. Tight as hell too. Kind of bordered on harsh and I think that could be a descriptor if it were played with the wrong settings/guitar. I liked it though.

Then I put in the JJ, and the tone was very menacing, more low mid growly kind of thing. Definitely more lows, highs were a bit more breathy, rounder tone. It was a really hard decision but in the end, the JJ got me, which is something I didn't expect since I'm not very fond of them (I found zero use for them in my Marshall for instance). I swapped the Shuguang and it in and out and in the end I think the JJ brought me closer to what I was looking for in a Mesa.
The tone is a bit more "driven" with this tube so to speak. It's also a tad more compressed which could turn into a gripe but I'll see.

That's it for now. I'm dying to try out an EH 12AX7, I have a feeling it might be the best of both worlds.

Question for safe tube rolling - is it enough to turn the TriAxis off when I'm about to swap? Or should I also put the 2:90 on standby?
Also, if V1 is Lead 1 Input and V4 is Lead 2 Input, then V2 is the Rhy input? It says "all other modes" and that's all that's left. Wonder why they labeled it like that in the manual.
 
I had the Tung in V1 in for a couple of days, and the JJ in V4. Turns out I really like it, the Tung opens up the Lead 1 Red mode nicely and makes the low end less squishy, makes the mids smoother and the highs are not piercing. The JJ makes the Lead 2 tones a tad more "driven" and it really makes those Mesa low mids shine.

V2
I guess this is the "Rhyhtm" input? This was wierd. I swapped the stock Sovtek 12AX7WA with a Shuguang first - didn't like it, too bright. Then I put in the TungSol and it was missing something, I can't put a finger on it but to me it was a bit stiffer and just a tiny shade darker. Didn't even bother with the JJ. Anway, I A/B/C'd a little and I found out I like the Sovtek 12AX7WA anyway! After like a half our of testing I decided why fix something that's not broken, and TBH I really liked the clean tones of this rig right from the start. The Sovtek was "cardboardy" in Lead 2 and too mushy in Lead 1, but it generates a very nice clean tone.

I guess the Sovtek 12AX7WA is a good tube when it's not clipping. :D

Now this question I have asked MULTIPLE times on this forum and I never got a satisfying answer. So here I go again: What does one achieve with swapping the V3? It says "Lead&Rhythm mixer", the hell is that supposed to mean? I also read it's the DV input buffer and that some put a lower gain tube in V3 to prevent the DV circuitry from clipping.
 
V2 is the rythm LD2 input tube. V4 is the drive tube for LD2.
So changing V2 affect both rythm and LD2 modes.

V3A is, if I remember well, the tube that drive the OPamp, that's why a lower gain tube such as 5751 or 12AT7 is preferable here to avoid saturating the OPamp.
V3B is part of LD1 red mode. No matter about the gain of that specific triode for LD1 as it's a cathode follower before the EQ.

If you can, try also a 12AT7 in V2. Cristal clean without loosing that gainy LD2, and remove some blur of the LD1 red mode.
 
Thanks for that.

I guess I'll try fooling with V2 some more to see what it does to the entire preamp. I thought it was only the Rhythm input and V4 is the Lead 2 INPUT, not gain stage.

It's cool to tube roll a TriAxis, all you do is turn the rack around for easy access, turn it on/off and swap tubes.
 
Taken from http://tubefreak.com/triaxis.htm:

INPUT -> (V1) -> V2A -> EQ -> V2B -> (V4) -> V3A -> PRESENCE -> VOLUME -> TL072A -> DYNAMIC VOICE -> TL072B -> (FX SEND) -> (FX RETURN) -> V5A + V5B -> MASTER VOLUME -> OUTPUT

signal from V5 -> TL072A + TL072B -> RECORDING OUTPUTS

V1A = Input tube for Lead 1, it's only in the signal line when LD1 is engaged.
V2A = Main input tube for all other stages and gain tube for Lead 1
EQ = Treble (plus shift for different voicing), bass, mid
V2B = After EQ section
V4A + B = Gain for Lead 2, it's only in the signal line when engaged.
V3A = Pre dynamic voice
PRESENCE
VOLUME = programmable volume of each preset
TL072A = Opamp (IC3)
DYNAMIC VOICE = programmable 6 band graphic EQ
TL072B = Opamp (IC3)
FX SEND/RETURN = Only active when used
V5A + B = FX return for channel A and B, main output tube
OUTPUT + MASTER VOLUME = normal outputs, volume does not influence rec outputs
TL072A+B = Opamp (signal comes from V5)
RECORDING OUTPUTS
 
He don't speak about V3B, wich is used in LD1 red mode. What I don't know is if it's used only in TriAxis with the TX4 board or not.
 
Triaxstasy - thanks for that, I knew of that link but I couldn't find it anywhere! :D

I also noticed that V3B isn't mentioned. Perhaps you are right and the recto board triaxis' don't use it?
 
Ok found the schem agin
http://www.freeinfosociety.com/electronics/schemview.php?id=298
V3B is used in LD1 red, but also mention also TX4 board, so it's maybe not in use on the early version of the TA.
 
OK so finally I got an EH 12AX7, so I quickly popped it in V2, A/B'd it with my Sovtek and I loved it! The clean was less bassy (thus more clear), the highs were warmer and more smooth. It also cleaned up Lead 2 and rounded it out some more. Great stuff!
 
I like those EH for cleaning up, redefine a bumpy/bassy sound !
Did you see this post ?
http://forum.grailtone.com/viewtopic.php?f=5&t=749&start=0&hilit=retubing+triaxis
 
Yeah, and it's not my cup of tea, don't care much for NOS tubes.

Turns out this mini tube roll lead to me adjusting my settings a little (less gain/lead drive), probably because of the added gain of the JJ tube.
 
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