Im thinking of upgrading the tubes in the EMX, heard that the sound quality become less muddy. Does anyone own one of these that can prove this?

 

@ Ztriumph,

Maybe this is because your 2 'Premium Tubes' are a bit used by the time, because their qualities (as new) are rather among the best you can find for this kind of Tubes...


Electro-Harmonix 12AX7 Preamp Tube is a low noise, high gain tube with highly musical tone, and detailed harmonics.
Thanks to its unique spiral filament, short plates and halo-getter, it offers tone comparable to ultra high priced NOS tubes.

So if I was you, I'll buy new ones if necessary, but I'll certainly keep that Model and Brand : 'Electro-Harmonix 12AX7EH'...

Other '12AX7' Tubes that you can find here and there (for cheaper prices) are 'Chinese' ones. Not to complaint, but these are certainly of lower quality and musicality.
Other ones, as for instance : 'Mullard' (higher prices and almost the best 'Tubes' that you can find) can do the 'trick', but they're rather done to be used within Guitar Amps & Preamps (e.g. 'Marshall'),...

But as always, there's not absolute rules ! Try by yourself if you can, and get your own opinion. *yes*

 

Years ago I had both EMX and ESX-1, and tbh, the factory tubes are quite crappy.
Russian made EH, the only thing people like when driving tube circuit in electribes is probably that they're really loud,
other than that, they distort as fuck, and not exactly that kind of distortion you usually like and are after.
I never changed tubes on my machines, actually almost always used them at tube gain between 1-2 on 10, for the above problem.
But I was running them through a couple of outboards that added some nice mojo too,
an exciter of an unknown mark but pretty good + dbx166xl and THC-00 Resinator Filterbox
OT: I had a decent 303 clone by F.A.T. too, and it was called FB-303 Freebase
A friend of mine changed the tubes on his ESX with
THESE ECC83 if I remember well.
A bit quieter overall level, but much less distortion, and a nice kind of distortion.
Remember you have to tune the valve level with the trims that are placed near the valve socket after replacing, pretty easy job btw.
Never heard Mullards on electribe so I don't know, but I can bet my balls they're better than stock EH *yes*
Wishing you happy experiments! Let us know if you do the change what are your feelings

 

@ Ztriumph,

The following Article can certainly be of great interest for you... *yes*

You'll find the most current made Tubes nowadays, their characteristics, their notations,...


12AX7 Comparison of Current Made Tubes

 

I've been working with these dual triode preamp tubes in my business for a few years. The EMX-1 and every other Korg with a tube in it that I can remember is a starved-plate design. There might be 30 volts at the plate compared to the 100-300 volts the 12A_7/ECC8_ tubes are designed to operate linearly on. Without going on and on about it, I'll say this: Those Korg circuits are never going to operate in the way implied by the existence of the tube. Because the audio signal is passing through the tube, there is the possibility that one tube will sound different than another in the EMX-1. BUT... putting an expensive NOS Amperex ECC83 in there will not result in much reward at all.

Bottom line: Don't put a lot of energy or money into this as the benefit will be minimal at best.

 

Probably gonna buy JJ ecc83s 20$ , why not, just for an experiment so i can figure it out and not be wondering.

 

Yeah, for 20$ is a nice experiment, though I have to agree with krameri,
don't expect wonders cause they won't happen, and don't waste too much money on it,
but for an experiment, 20$ are ok, and the point here is not to put hi-end NOS tubes inside,
just to trash those two crappy stock ones and put inside some decent tubes