I changed a Tube and…


I liked it!
 Have a Rogue Audio Cronos mag lll bought it years ago as original Cronos Mag  sent it in last year for the upgrade to lll .  Never changed any of the original tubes .

The amp was lightly used due to my changing amps like regularly. Decided to stick with Cronos and and have really enjoyed it . 
Playing vinyl for the majority of time and seem satisfied with Triode mode .  Amp runs perfectly no noise at all but thought about all the threads regarding tube rolling  especially the center 12au7 . 
pulled out the stock JJ and found a Genalex  Gold Lion ECC82/B749 (12au7)  bought them 7-8 years ago .  
Put the GL into center position and was thinking “am I going to really hear a difference “???   Figured I listen to a few LPs and maybe I’d notice something different good or bad Maybe ? after all it’s just one tiny tube !

Well I was blown away !, 30 seconds in listening to “two of a mind “ Desmond /Muliligan  things just got a whole lot more musical 🎶. Hard to describe everything seemed improved , midrange was wow ! Soundstage was better , etc .

Went to another familiar favorite Grant Green “ Idle Moments “   Oh yes the magic is here too 

Is this even possible or am I under a placebo delusion  lol 

Now I’m really wondering what about the other 2  12au7’s  and even the 2 -12ax7’s

what else am I missing ? 

 

 

 

mfm22

@chickenoregg  Perhaps I should have been more clear in my recommendation. I meant original Telefunken not the newer stuff. With diamonds–I know of no other. Included in that are those branded Fisher and Dynaco. While I am no expert, I have rolled hundreds of tubes over almost 40 years. I have found Siemens E83CC to have some of the characteristics of the Telefunkens but lacking the dynamics. Indeed my recommendation was in the context of the OP’s post of them being a new roller and may not be in the market for relatively rare and expensive Valvos. However, I do agree Teles are not the pinnacle of the clean and transparent. I use Teles in the regulators but a different tube in the phono amplification stage which has aa the benefits of the Teles but with more finesse. 

It makes sense for manufacturers to put cheap and available tubes into the gear they market.  The tubes they offer must be common and easily replaceable.  Because not everyone's taste and system characteristics are the same, there is no clear consensus on what constitutes and upgrade, so why should a manufacturer spend extra on fancy tubes that may make the sound "worse" to certain buyers?  This does leave it up to the customer to experiment and hunt for "better" tubes.  A local dealer in my area carries a wide array of vintage and new tubes and customers frequently borrow tubes to try in their gear to find what sounds best.  This dealer offers recommendations based on what the customer says he wants to change about the sound and discourages obsessive tube rolling (this damages tube sockets), but he knows that some swapping and matching may be needed by his customers.

@thecarpathian 

My understanding is that different shaped getters were used to guide/control where the barium patches ended up. I've always though of them like a wine glass that's designed for specific type of wine to maximize how that particular wine hits your nose and tongue; e.g.. like how a Bordeaux glass differs from a Burgundy glass.

They are also indicative of a date of manufacture. But after the vacuum is created during the production process, they really serve no purpose. I have tubes with huge foil getters that broke off at the post were it meets the mica and it rattles around in there like a maraca. They work fine, like more prone to issues down the road, but a tube with a broken getter is far from a horse with a broken leg.

@larryi 

But this starts with the false, outdated presumption that each specific model of whatever piece of gear must have the same tube as every other piece of gear with the same model number. In the age of co-creation where you get to pick the kind of wood you want your amp built with there is no reason you cannot specify also an NOS tube that is to your taste. The manufacturers that embrace this instead of fighting it I think will be better for it.