LTA MicroZOTL tube upgrade

@larsman 

We chase sound quality, but contentment is a higher mountain to have climbed. I am considering an LTA Preamp and LTA DAC to pair with my VAC 200IQ. Perhaps I will meet you on the summit soon.

Thanks @chickenoregg,

I also have 聖HIJIRI HCS Speaker cable and with the ’Hotness’ of the (1) Sylvania 6SN7W metal base, (1) Sylvania 6SN7GT metal base and the (2) matched NOS Telefunken ECC801S’s tubes the full loom of  聖HIJIRI took care of all the hot high treble playback without sacrificing clean smooth high treble playback. Not to mention my dac of choice  is an R2R dac with a gorgeous warm bloom so the synergy is working.

What do you think about me sourcing an extremely rare Matched Platinum pair of 1965 NOS Melz 1578 (6H8C/6N8S/6SN7) Tubes, Black Holed Plates, Foil Getter, Matching Date Codes (etched code "65" on the glass and printed code "67" on the base for the 6SN7 positions?

And with that said, as I know you have to be real lucky cause it just may take an act of congress to get authentic 1965 NOS Melz 1578 (6H8C/6N8S/6SN7) Tubes as you don’t want them to pssst...Away into thin air. And that’s one of the reasons I bought the LTA MZ3 because of the very minimal use of current to the tubes which is supposed to extend tube life.  

@tyray 

I have a tragically funny story about Melz 1578’s.

When I was but a wee Tubesman doing one of my first big acquisition deals the collector I was buying from sent me a spreadsheet of all this tubes. Some of the stuff I had no clue what was, so in doing my valuations I looked up as much of the unknowns as I could but was running against the clock to get back to him with a lump sum number for the entire collection. So I marked what I didn’t know what was and didn’t feel I had time to look up as zero for their value.

So I marked 6 pairs of Melz 5-Hole Black Plates and 6 pairs of Melz 5-Hole Grey Plates as zero. And forgot about them. Until all these huge moving boxes of the world’s finest, rarest tubes ever produced show up. In the manic feeding frenzy that ensued (think Scrooge McDuck diving into his money pit) I had pulled a pair of some goofy looking tubes out of their boxes and set them on my counter, turned around and then turned back around when I heard them shatter when they rolled off of the counter and hit my kitchen floor. And then I looked up what they were and sat down real slow on a chair and contemplated the absurdity of my crime.

Truth be told, I find my peace with having marked those as zero because half of them were unpredictably microphonic/noisy, so much so that I didn’t dare risk trying to sell any more of them so I traded them to friends/other sellers. The glass is extremely thin and the connection of that glass to the metal base is as fragile as I have ever seen on any tube. I had two Melz tubes meet their end in transit and I pack my tubes like they’ll be air dropped from 42K feet to you in Class 5 Hurricane. Only two tubes (in separate incidents) I have ever lost out of god knows how many I’ve shipped.

I would describe the Melz as having the biggest, most in your face sound of any 6SN7 (or really any tube type) that I have heard. They are definitely a dynamic tube. I have heard the word explosive used to describe them more than once. And that fits. That’s not too say they didn’t sound great, they did. But my preference is far more aligned with the GEC B65/B36, I like the highs, love the mids and like the bass. Some say the B65 falls down bit in the lows, not controlled/tight/extended enough, and while I wouldn’t disagree that that is the B65’s weak spot, I think a bigger deal is made out of it than it is — in my and my client’s experiences. I won’t say run away from the Melz, but tread carefully as there are a lot of ways you could regret shelling out the better part of a grand for a pair of tubes that in my experience is prone to being microphonic and preciously fragile in its construction.

As a seller, I kind of have to laugh at "Platinum Matched." True platinum matching is an extremely rigorous process of burning in and testing and burning in and testing and selecting the best of the best tubes based on a number of different criteria, which importantly, beyond gain, etc., includes if the tube can sustain a stable bias. I doubt any Melz being sold now were factory matched in this way, and instead are being matched by some seller on a non lab-grade tube tester (which is nearly all of them, including Amplitrex) that tests the tube so far out of spec from the conditions the tube will see being used in amp or preamp, they are about as accurate as a litmus test in determining a tube’s true health and how it will behave in real world conditions.

Have a great holiday.

@chickenoregg,

Brimar Triple-Mica Black Plate CV4024. Sometimes these will also be coded as 6060 or CV455, There are square getter and halo getter tubes and both are great. Probably $200-$250 matched pair.

Last night while rummaging through my limited tube stockpile I noticed that my stock tubes for my LTA MZ3 input tubes preamplifier section are two 12AT7 NOS Brimar CV4024 KB/AD 12AT7WA/6060 AD VL 393/3980 British military grade with an upward arrow.

Turns out, if what you wrote is correct, those stock tubes are actually quite good for their low costs. Although they are only dual mica they are actually NOS. Meaning they are really new and not the fake NOS tubes that sellers what to sell. Who’d a thunk it.

And the stock NOS RCA JAN CRC 12SX7GT US ARMY/NAVY military grade tubes for my LTA MZ3  power output amplifier section are also rated to work just fine for their low price cost to performance ratio. And yes these were also true NOS.

If I had taken the time to burn them in along with the LTA MZ3 I might have just been fine with their performance cause they had already been picked as being perfectly voiced for the LTA MZ3 application. But no! I had the disposable cash at the time and called myself a so called audiophile! I could’a saved myself a lotta coin. You/we live and learn.

One more thing, how do I get my text to look like and match the text you posted above? Thanks.

Everyone, I hope you have safe and wonderful New Year!

@chickenoregg,

I’ve been researching the GEC A9000 Version 1 and thanks to you it tickled my fancy and I will be entertaining an upgrade when time and funds permit. Thanks again.