Paul S wrote:

Well, I thought I'd heard some nice hi-fi at times in the past, but this is something else, altogether!  As the new 6AK5s burn in the amps have become truly uncanny music makers.  The "highs" are now such that it has become unimportant where I sit in relation to the speakers, and I have just listened to some of what I always thought were poor recordings of some performances I love rendered not only "listenable" but downright, bloody musical.  Somehow, in sync with the "missing" HF, these amps seem to pay attention only to the music, and they are otherwise silent.  I don't know how to put it any better than that.  This is simply not like hi-fi as we have known it before now.  Yes, it is much "better". I will follow Romy's lead and stop short of a blanket recommendation, because any tool can be misused; but at the same time, I never really imagined reproduced music could come literally so close in every respect to live, without the accompanying noises, etc. that have up to now invariably tagged along as part of the price for a "ruthlessly revealing" system.  In this case, just take out the "ruthless" part and add a significant chunk of new-type information to what you have heard to date in terms of "revealing".  It's music, but not at all in the same sense as all the PRAT-oriented mid-fi stuff that always gets that citation from reviewers.  I mean MUSIC! If new 6N6Ps add anything substantial to what I'm getting now, I'll have to be tethered to keep my feet on the ground! Happy New Year, Paul S

Paul S wrote:

The 6N6Ps I bought are nothing "special" as far as I know, but they are all tested and to spec, according to the seller, so I will also replace my current 6N6Ps when the new (NOS) batch arrives, and I will note any changes in sound then, too.

I would not trust any seller who clamed that they tested them. What they tested: transcendence, cathode emission, at which current? Come on, no one test those tubes and partially as “expensive” as $2 worth tubes. There are two options. First: your 6N6P that you got in the ML2 was good to begin with. Considering that I know the person from whom you bought your ML2 I might assure you that the amp did not work in his home at all. Second possibility is that you juts did not “catch” the change. You see, when people re-tube amps they look for the changes in Sound that I characterize as vertical or diagonal change. It is true for ML2’s input stage but with the driver stage it works differently. Changing the driver tube in this amp affects something that I call “horizontal change”. The horizontal change has less to do with “sounds” and has more to do with accentuation of rhythm and dynamic emphasis in “fundamentals range” (presumably if a playback can hands it)… As the side-evidence of the worn of the 6N6P you might look for the dark amalgam in sides where the electing bombarded the glass. That would be a good indication how much tube worked.  The dark sided are not necessary indication of the bad tubes, you need tube tester (and the skills to use it) to say anything more or less defiantly. Still, with 14 cents per tube that I paid I changed it each six month when a gray coloration of the side juts tube to brown. Ironically, even then I did hear the “horizontal change” in the sound when I employed the new 6N6P..

Paul S wrote:

You have said that there are no "good" 6N6Ps; but are some physically constructed better than others?

Nope it was not what I said. I said the all 6N6P are equal, at least among those that I have seen and there are no reasons to pursue different production versions. (Some Russian tube from 60 generally better then form 70-80) There is a deviation on tube tester there between the new different tubes but it is hardly auditable.

Paul, also, I my suggest that you a little bit too “violently” took the ML2 and your recent obsession with re-tubing of this amp is not good thing, at least it’s how I see it. You got a new amps and it looks like you like it. It is fine but what makes you to be fascinated to change tubes in it? Are any specific problems with sound while you use your current tubes that from you point of view makes the ML2 to sound bad? I do not think it is how you feel. So, if you have normally operating ML2 then spend a month of two juts living with it and getting accustom to it sound and then VERY SLOWLY buy some spare of the tubes. This approach will save you a lot of money, lot of nervousness and will prevent you from immature decisions.

jessie.dazzle wrote:

I have an L2 that uses this tube (at an alarming rate!), so I try to keep a stock of them..

Yep, as the person who was the very first who alarmed public about the L2’s 6C19P-sysndrome I very much concur with what you said. Lamm keep shameful silent about the issues, in fact I did not even know if he knew about it 5 years back and eventually the numerous companies made him to make an announcement that the tube should be changed once a year. Yep, right – one a year my tail!!!  I remember at the best times I was clearly able to distinct the 6C19P that worked for a week (!!!) in Lamm L2 preamp. I really do not know if it is the problem with 6C19P of with the way how Vladimir uses it. Theoretically it should be very simple – juts a common regulator but I did not look further into L2. In my headphone amp the 6C19P sits at near 170V, 20ma with -33V at bias… It works fine with huge microphones (1 out of 10 is suitable) and it looks like it still work there “faster” then It would be expected. Still, I do not use that headphone amp too much to make more definitive conclusion…

jessie.dazzle wrote:

Regarding power cables : In my case, grounding made a difference. Since you are making your own cables, you may want to consider "lifting the ground" and taking advantage of the chassis grounding lug Lamm provides, connecting your ML2s (and ideally the rest of your equipment) directly to a dedicated ground (using one of those long copper-coated grounding rods just outside the house).

Jessie, it has nothing to do with Lamms. The use of grounding that come from the “wall” should be absolutely prohibited for means of high end audio. The entire audio installation MUST be listed form the wall’s ground. It is very basic and very essential requirement.

Jessie,

Actually the tendency of manufactures to isolate ground becomes almost common among any more or less serious manufactures nowadays. The main’s ground is so polluted in US hat it is scare… or even dungarees. I remember a few years ago when I was setting up AC polarity for my playback I was measuring some VERY ugly sings on the ground side….

I have my cooper poll drive in backyard but also, and do not try it home; I had a few years ago a period when I was driving the entire single ended system completely flooded. At that time I was e4xremeting with active basing of the cable and I remember I got some very crazy setting. I had for instance a couple weeks the system running 110V in one wire and 220V in other wire… of course completely lifted…. and it was 11 components. It was interesting time…

Anyhow, since it is Lamm ML2 thread I’m jumping off the subject of grounds. The only thing that I would add on the subject of the thread would be that on all 4 of ML2s that I owned removed the input filters filters. Vladimir used in ML2 power entry modules that combined fuse, power receptacles and common mode rejection filters. What I did was broken off the filters from the power pins and lifted the ground cable form the unit to the power entry module. It was possible to order to $6 the identical power entry module but I decided do not bother. I personally feel that even the discreet, build with the best possible parts, with the best possible techniques, make to the very specific  and very exact current common-mode and EMI filters do eat dynamic, among the other thighs. However, in the ML2 used $11-worth cheap filter that I thought should be removed. Frankly speaking the effect of removing was much less notable then in some other components (I toss it always everywhere) but it was auditable. Though I admit I do not spent a lot of efforts to confirm it but instead I  juts bite the filter off and forgot about them….

Actually I was wondering what the hell you were talking about what you were bitching that the ML2 socket can not handle 6N6P first. Ether you changed over 10.000 tubes in there or something else was wrong because the ML2 sockets are fine (except the 6C33C) and you should not have any problems. A possibility that you got some too skinny pins might explain it. I do not know, perhaps your party are more skinny then necessary. When I used ML2 I got a box with 100 of them for $40 (1966 made) and the pins were fine, no smaller the usually. You can always slightly bend the pins in order to make them to more firm.

Perhaps the skinnier 6N6P do exist, I do not know. If I were you I would call Lamm and ask, he obviously when over many of them. BTW, he might propose to buy 6N6P from him because he takes the skinny one tine and galvanizes metal on the pins unit the pins become larger. The price of 49.99 per tube is because during this galvanization he uses invented by him unique technology to let only females elations to stick to the pins and keep male electron wad of the tube. The reasons why it is important is because when you pay $80 for 6C33C then you have output tube has only males electrons on the pins and it created a natural flow across capacitor captor. Lamm own a paten that teachers the any capacitor hates when electrons with the same sex intermingle and according to Lamm his “sexism in amplification” helps to eliminate the capacitor’s homophobia….

BTW, you will not be able to use Absorb-GEL adapters because in ML2 the sockets are board mounted and the tube are going there the holes in chassis (I like it a lot). The Absorb-GEL adapters would need to have a surface with the sole on it so they are not the solution in your case.

The caT

Paul S wrote:

At this pointIi think it's fair to say that if you have ML2s with "reasonably efficient" speakers then you can safely just hew to whatever works best with the ML2s and toss the rest, because in that case "the rest" is not worth keeping.

jessie.dazzle wrote:

While not present to the point of ruining the experience, I would love to reduce the background hiss coming from the MF and HF horns/drivers.

jessie.dazzle wrote:

I have also noticed a shift in the music ….. I've certainly been adding more and more complex music …. this is stuff I used to avoid... no longer the case. And simpler music sounds... simple.

I think nothing further could be said about ML2.0, this sumizes it all.

jessie.dazzle wrote:

"Short the ML2’s inputs and the hiss should be gone" I assume it is not a mistake, and that you mean short the unused input on each POWER AMP (as opposed to the PREAMP). (I am currently using the XLR connections because I don't have RCA cables in the correct length) Is there any advantage (or danger) in shorting the unused INPUTS on the PREAMP? For the moment I have metal sheilding caps on all unused inputs (pre and power amps), which don't seem to make a difference.

Nope, it was not what I meant. Do following:

1) Disconnect ML2 from preamp.
2) Disconnect any RCA or XLR from ML2.
3) Stick RCA shorting plug into ML2’s input RCA jack (not the shielding caps but shorting)
4) If you do not have a shorting plug then stick RCA male-to-male into ML2’s RCA input and then short the other side of the RCA terminator with any metal object.

What you will go is shorting the grid of the input stage to ground that will kill all externals noise. In this mode the ML2 should be absolutely silent.