Johnnysound
100+ Head-Fier
Hi cf.
Am so glad that you, like @Johnnysound , stuck with my pleas to give these ('coated') ST CV1052s lots of burn-in time...I personally found they need more time even than some of the (notorious!) Russian (small) tubes!! And I still cannot believe just how much they changed well after 100 hrs...especially when 'conditioned' by many different pieces of music across the entire FR.
These have proved beyond any doubt that tubes not specifically configured for in a circuit sometimes can perform brilliantly, regardless of what theory might dictate. As I have stated many times before, one should trust one's own ears in such matters, and not be overly swayed by what others (including 'experts') say...so long as said tubes are shown to be safe to use! On which subject, I have to say also that these ELs especially have been prone to none of the gremlins that sometimes curse other tubes used in 6SN7 and 6AS7G/6080/6BL7 circuits. On the contrary, mine have proved to be the quietest, hum-(and other gremlin-) free tubes I have ever used in my amps...bar none! That they also outperform all of them - often at a fraction of the cost - and run the amp incredibly cool, has me still in disbelief !....CHEERS!...CJ
Hi H1, you mentioned the long burn in time needed by Russian “small” tubes...since all tubes are system dependent I must say (again) that I still consider my ( rare) Melz 6N1P-E triple mica, box plates from 63’ some of the very top drivers in the Euforia. In this particular amp, IMHO, superior to any 6SN7 that I have tried (and I have quite a few nice ones). I read that the 6N1P was designed as a cold war effort to surpass the specs of the U.S. 6SN7 in a small format, from the start as an audio tube, and it shows.
Super extended top to bottom, linear, quiet, and above all a rich, dense, dynamic, musical and pleasant sound. Curiously, they do need quite a warmup to sound best, probably an hour or so. I have used mine some 40 hours, and yes, I feel they need much more playing time to completely “open up”.
The good news is that right now there are a few offers of the 6N1P-E triple mica from the sixties on EBay at very good prices ! This is a quite rare tube, normally very hard to find, and believe me, the current stock will be sold in a few days, and will not appear again for a long time....
But the small Russians will have to wait , all my “amp time” is devoted right now to the CV1052 “dark glass” quartet. Some 130 hours plus...and I feel they have not reached their peak yet. These tubes are unlike any others that I know of.
All tubes improve with burn in, of course, and after some time you can be reasonably sure that the tube is “mature” , say some better defined bass, subtly more open sound, and so on, and it stays like that. Not the CV1052s. The current draw is so tiny that the process is not only extremely slow, but gradual and incremental in very small steps, and most important, in my experience the results are very different than with other tubes. While you can expect, say, marginally better bass, these tubes evolved (surprisingly) from a quite “polite” and a bit restricted bass to something very different: a seriously deep, tight and accurate presentation. This is not a “normal” burn in. This is not marginal. My mad theory is that the very low current draw maybe has some unexpected effects in the tube internals, apart from the quiet background. Slow cooking is always better....Who knows ?
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