Rerurn to Romy the Cat's Site
In the Forum: Audio Discussions
In the Thread: Initial thoughts about new/old Lamm ML2s
Post Subject: No, not about the tubesPosted by Paul S on: 1/5/2007
Actually, Romy, it is simply that the tubes that came with the amp were not "good" in the sense that they were not doing their jobs. Period. You may remember the pulses through the speakers and how new input tubes cured the problem? So, no surprise then that the new input tubes also improved the performance/sound. So far all the tube "rolling" has been about nothing more than a systematic attempt to be sure that the amps are operating to spec; that's all. But of course I figure I may as well get 'good quality' tubes while I'm at it, if there is such a thing. Why not do something right the first time, if you can? And who should I ask to find out about these things?
You expressed surprise that new 6AK5s made such a profound difference. Well, please don't think that I think it is the brand or cryogenically treated pins that made the difference. At this point I do not believe that the brand of 6AK5 influenced the sound. But it certainly appears at this point that properly-functioning 6AK5s had a hand in subsequent performance improvements, which were not at all subtle, and in fact brought my amps closer to what others have described, that I up to now could only intuit. Am I pleased with the results? You betcha!
Like I said, the 6N6Ps presently in the amps are the last tubes that came with the amps, and I have absolutely no reason to suppose that they are woring to spec. I will try the new ones I got and listen to the results. And since I know they will need regular replacement I am stocking up, so I don't have to deal with it later.
And don't worry. I do not think I am listening to "tricked-out" ML2s. Rather, I figure I am hearing the amp running ever closer to spec. Pardon me if I am agog. No, these amps are not "perfect". But they are so much better in every way than anything else I have heard in 40+ years that it just makes me wonder how they even happened.
In writing my ML2 impressions I am: 1) Trying to take advantage of your extensive experience with these amps. 2) Re-capping my experience in simple, rote terms. 3) Sharing my personal impressions/reactions as I go along.
With respect to the ground issue: Romy, as you know, in most residential/commercial installations the "neutral" wire of the pair powering the gear runs back "unbroken" to the same main ground bus/rod as the "ground" wire. Code (and common sense) absolutely demands a whole-system ground at/near the main electrical service. A first-class installation will use separate neutral and ground busses at any secondary panels and just join neutral and ground wires at the main panel ground bus. When we use a dedicated ground for the "ground" wire from our hi-fi systems most of us are really using 2 routes to ground: the original neutral-to-main-panel ground and any "dedicated" rod for the system ground. I also do the dedicated ground trick, by the way.
Best regards,
Paul S Rerurn to Romy the Cat's Site