JJ Tesla ECC83S tubes for ART Pro MPA mic preamp
Has anybody tried the new JJ Tesla ECC83S tubes yet as a replacement to stock OEM ones?
I want to replace the tubes in my recently-acquired ART Pro MPA mic preamp. The only experience I've had in "tube rolling" (as the audiophiles refer to it) is replacing the stock tubes in my VTL TL2.5 stereo preamp with NOS Mullard 12AT7's and 12AU7's. BIG difference! Tighter, punchier bass, lowered noise floor, more detail in the treble, overall it was a terrific cost-effective upgrade for my audio system.
I also replaced the motley collection of tubes in my Ampeg SVT 3 Pro Bass head with new Electro Harmonix tubes and enjoyed a quieter amplifer, with less crispy overdrive and cleaner output.
I was thinking of trying the new JJ Tesla's as they are supposed to be a modern copy of the revered Telefunken 12AX7's. I was wondering if anybody had an opinion on these tubes or perhaps on another brand that you tried and liked in your ART Pro MPA.
If you like the Mullards I may have to give them a try just for the heck of it. I've been a fan of the Tesla ECC83S for a lot of gear though and they do very well in my Pro VLA.
Anyone try the GT Gold series tubes in their ART Pro series stuff yet? Cucco says they're great tubes but I haven't heard of anyone using them in a Pro VLA or MPA yet.
If so, is there sufficient overall gain in the preamplifier to make them useful without a corresponding increase in noise?
As it is, I've ordered a couple of the JJ Tesla ECC83S but am interested in understanding what the effects of these different specification tubes would be.
While I'm thinking about it the ART Pro MPA is specified with 12AX7A tubes. I'm substituting 12AX7's (without the "A" suffix).
The Tesla/JJ's are 12AX7's, they're just called ECC83S's. So you're getting the same gain levels with them a 12AX7 gives you, but smoother and more balanced (IMO). More of an audiophile-type performance.
Here's a good table on the differences between the aX7 type tubes.
ECC83 is the European nomenclature for the 12AX7. 12AX7A can be used in parallel or series circuits, the 12AX7 in parallel filament series circuits only. Ohhh.
I haven't had any trouble using 12AX7's instead of 12AX7A's. Any AX7 category tube has a gain factor of 100, the DF7's and AT7's are 70. They're much easier to use on vocals due to the lower gain. It's almost impossible to drive one into distortion, as well as being warmer sounding.
With the ART Pro, I plan to experiment tracking Elec Bass Guitar and don't mind if I can get some overdrive on the sound, so for now I'll stay with 12AX7's. My Focusrite Trakmaster give me a pretty clean DI bass sound. I'll see if the ART can give me something different. I think it will.
Try cascading channel 1 into channel 2 for some even cooler effects; i.e., limit one channel and compress the next or whatever.