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  »  New  The RCA’s 6C33C sockets?..  Total Mass...  Melquiades Amplifier  Forum     9  84182  06-19-2005
  »  New  Initial thoughts about new/old Lamm ML2s..  Voltage Divider in ML2 Input Stage...  Audio Discussions  Forum     215  1656668  10-12-2006
  »  New  Shock-absorbing tube sockets...  Skinny pins and cheap-o sockets...  Audio Discussions  Forum     11  78714  12-21-2006
09-28-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,570
Joined on 10-12-2006

Post #: 1
Post ID: 8399
Reply to: 8399
Relief from micro-arcing tube pins?

Wonder if ordinary "di-electric grease" would work on tube pins?  Anyone ever try it?

It works for old car distributors and electrical service connections, which is to say, other high votage applications.

Like I said in the ML2 thread a few posts back, I found out the hard way that Caig "contact cleaner/enhancers" do not survive the tube pin environment, not to mention truly disasterous results with the old "Tweak" "enhancer", not just on tube pins (eeek!!!) but on ANYTHING.  A common pattern for not-up-to-it "enhancers" is, sounds better at first but quickly declines to way worse, then it's a PITA to clean it off.

Do I have to be the Guinea pig?

Paul S

09-28-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,049
Joined on 05-28-2004

Post #: 2
Post ID: 8402
Reply to: 8399
It is all depends from…

…. what tube’s socket is arcing. If the tube juts started to ark then bending the tube legs, cleaning the sockets 9scabng the meta with no marks of the ark left) and treating it with conceive grease might help. Do not forget that most of the sockets have pretty much a point contact (unfortunately) and bending the socket’s legs you juts offset the contact point to the location that was not damaged by ark.

If your socket was juts was crappy to begin with, got rusty or it has no good access to maintain it then it would be easy to replaces the socket. On your ML2 (if you are taking about the small tubes) you would need to lift the circuit board, you do not need to take it away, juts to lift it. It is 10 min ceremony: Remove a dozen or so of little screws from the PC-board, un-screw input jackets, take 3 connectors from the right side of the board and the board will be set free to open up as book’s page. If you can solder well then you have no problem to put a new socket, if not invite somebody who has good soldering skills. BTW, the soldering skills of people who assemble ML2 are superb, and it assembled VERY tasty. I just wish they do Lamm point-to-point with the stupid PC boards… 

If you are in small tube world and have no option to deal with above then find a plug-in adopter with fat legs and use it between the damaged socket and the tube. The fat pins might stretch the socket’s pins and world offset the burned socket’s contact point.

If you have problem with the large tubes then I would not bother and to replace the old sockets. It is PERFECTLY NORMAL to replace the 6C33C’s sockets one in 2-3 years. Lamm used Russian and Chinese sockets, they are very bad, and they MUST burn in 2-3 years of heavy use. There is very easy access to them in ML2 and it is very simple to replace them, do not forget to discharge the PS cap’s before you do it. It is also a good idea to put there US-made Johnson’s sockets – the will work for yea and they have no conus-contact (like Russian) but a line-contact.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
09-29-2008 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,570
Joined on 10-12-2006

Post #: 3
Post ID: 8404
Reply to: 8402
New Parts for Old Dogs
Thanks, Romy.

Although I am most certainly not a DIY/electronics whiz, and have no aim to be, I can +/- read a schematic and I can solder OK, have a de-soldering gun, etc.

Yes, there's no question that these sockets are poor quality.  But when the electricity is so bad for so long I tend to think against the backdrop of bad sound and so I also start wondering about other parts aging, too, including caps.

In other words, I am like an old dog that lies down in the shade then wakes to find himself roasting in the sun, then gets up and moves only far enough to buy a moment's respite from the heat.

Best regards,
Paul S
03-08-2009 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,570
Joined on 10-12-2006

Post #: 4
Post ID: 9976
Reply to: 8404
What Good are Camp Followers
fiogf49gjkf0d
if they don't try something first and report back on occasion?

I finally ran out of patience and tried the damn automotive dielectric grease myself on the pins of 4 new tubes I just put in the Lamms.  I also for the first time and against my own previous advice cleaned the pins with a tiny stainless steel brush mounted on a router (no, not a Dremmel; I couldn't find it...).  Well, THAT got the scale off, you betcha!  It also scratched the Hell out of the 6C33C pins and about melted the 6N6P pins, which is why I would not do it previous to using the grease to heal the wounds.

So far, so good.  After I did it I actually made out (without trying) several previously-unintelligible words and phrases in several albums I listened to, this with less attendant noise than usual but without the usual-for-audibility increased "sense of clarity";  ie, it did not SEEM clearer; it just WAS clearer.

Coincidence?  It is true that there are generally all sorts of jittery electrical effect and attendent noises going on around most contact points, and it is true that the high-voltage dielectric grease measurably damps this noise in places wher it has actually been tested; only, I didn't "test" it, apart from listening.  Whether it will stay calm or develop or cause new problems (like the Caig, etc.) remains to be seen/heard. 

So stay tuned.

As I mentioned in the ML2 thread, unless a related problem develops before I get to it, I am going to grease the K&K phono stage tube pins next; and after that... the World...

Paul S
03-15-2009 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,570
Joined on 10-12-2006

Post #: 5
Post ID: 10019
Reply to: 9976
Greased Lightning
fiogf49gjkf0d
Today I OCD'd my way through every freaking connection in my system, cleaning all connectors, daubing them with dielectric grease and re-connecting them.  Included were electrical plugs, RCA jacks and plugs, tube pins and sockets, cartridge pins and ground connections.

After I finished the task, I fired up the system and held my breath.

No problems, at all.  In addition to the increased clarity that usually comes after cleaning I noticed a distinct general calming of HF.  After the amps warmed up, the HF exhibited that rare and coveted quality of being "off" unless there was musical information present.  This gives the HF a watered-down version of the "spikey" quality it has in live music, and this is something I just don't hear from hi-fi.  Pretty cool.

Now, let's see if it holds up better than the Caig, etc...


Paul S
05-23-2009 Post does not mapped to Knowledge Tree
ArmAlex
Iran
Posts 106
Joined on 02-15-2009

Post #: 6
Post ID: 10561
Reply to: 10019
Lubricating connections
fiogf49gjkf0d
I've tried this before but only for power cords. I used silicon lubricant, which made system quieter but once I applied too much music became a little lifeless.
05-23-2009 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,570
Joined on 10-12-2006

Post #: 7
Post ID: 10566
Reply to: 10561
Still Going...
fiogf49gjkf0d
The thing I like best about the high voltage rated dielectric (silicone) grease is that it (apparently...) works and lasts on tube pins and sockets, while the Caig stuff I've tried works for maybe a session on tube pins and sockets, and then it goes bad.

Nothing has been re-cleaned or re-treated since my previous post, which means the last treatment is still effective for all connections where I used it.  (I have not tried, nor do I plan to try, greasing rotary-type switches).

If I remember correctly, the Caig worked for 4 - 6 months on low voltage connections and switches before it needed renewal.

Best regards,
Paul S
Page 1 of 1 (7 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  The RCA’s 6C33C sockets?..  Total Mass...  Melquiades Amplifier  Forum     9  84182  06-19-2005
  »  New  Initial thoughts about new/old Lamm ML2s..  Voltage Divider in ML2 Input Stage...  Audio Discussions  Forum     215  1656668  10-12-2006
  »  New  Shock-absorbing tube sockets...  Skinny pins and cheap-o sockets...  Audio Discussions  Forum     11  78714  12-21-2006
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