For nearly a year, I try many lamps in different configurations on my old Hot Rod Deluxe U.S..
The choice of lamps pre-amp, the 12AX7 or equivalent, can be a real headache. Not easy, in fact, find lamps that meet not only the amplifier but also a good compromise between the dynamic, good record of all frequencies and the desired sound character.
So I went through various tests by drawing with JJ, Sovteck, Tung Sol, TAD, Ruby, and of course, Groove Tube.
To my taste, the JJ showed too aggressive in the treble drive, the Tung Sol interesting to drive, lacked character and shine in clear, well-balanced TAD (the RT008 model) seemed a little too "straight ". Came out of the lot Sovteck (WA model) and especially Ruby (Model AC5 HG +). The latter V1 seemed to be an excellent solution with Sovteck in V2 and V3.
And then, by dint of practice tests, it inevitably happens when one is not sure of anything! Thus doubt hugging me (!) I finally decided to give the good old Groove Tube original. And it seemed to me that it was ultimately the best solution ... Including maintaining Ruby V1. My approach was this: since high gain 12AX7 (like Ruby, so) suited me perfectly V1, I had to find an equivalent in Groove Tube. And mud! as recently Thomann offers trios Groove Tube matched low and high gain.
My choice is logically focused on the pack, especially after research I soon realized that the proposed Thomann at a very interesting price: indeed, it is found on the site of a French department store over 100EUR!
The result is up to my expectations: it is the best combination I've experienced. The lamps are also fully identified with their position in V1, V2 and V3 recalled on each individual box. And put an AT7 in V3 proves excellent! So my Hot Rod Deluxe has never sounded better: the clean channel has gained body (! Thickness or if you know what I mean) and the Drive and More Drive will show better defined while having a little more heat.
All this remains a matter of taste sound, I can not of course guarantee everyone that this kit is a must buy, but in view of the low price charged by Thomann I can only encourage you to test it on a Fender (I have not tried it on anything else) that requires three lamps preamp.
In any case, the search is now over for me: it will be the Groove Tube and nothing else!