[david62]

Harry,

  I'm not sure how the silver wire would hiss except if it was strained and about to fracture? The silver wire is hard to work with especially in the tight space afforded by the chassis and heat sink shields.That is a good idea to use a 80 watt iron to re-heat which would be faster and probably transfer more heat.
Dave

[david62]

Problem Solved! I bought a pair of RCA clear tops and replaced the JJ tubes and away went the low level staticy hiss!So much for new tubes.Now all I need to do is fix all of the particulars that I undid looking for the problem.It's great that it was that simple.
Dave

[hotrod]

 David,
  Great to hear.I'm glad you decided to try swapping in some different tubes before you tore into it again,you just saved yourself alot of head scratching.

[david62]

I have to re-wire a couple pairs of RCA's and re-connect the Russian teflons,which isn't too involved.I actually did find contact between the RCA bodies and the chassis on a couple of the RCA jacks,which I will correct.I ordered a couple of pairs of better quality RCA's which should solve that issue.Even with that ground loop,the Clarinet had very little hum.
Dave

[Bill Epstein]

Outstanding, Dave! Now you'll hear some music.

Do you know the teflon tape trick? Plumbing teflon tape wrapped a few times, pulled tight, around the barrel of the RCA where it passses thru the chassis will insulate.

[david62]

Thanks for that tip Bill.The RCA's that I removed have plastic flat washer insulators that are not the best.I will replace the jacks that were making contact if my order from Hong Kong ever arrives.I will use the teflon tape along with the washers.Can ground loop issues effect the sound other than signal to noise?
Dave

[tubesforever]

David,

Before doing anything run a set of JJ or TungSol fresh new tubes in your unit.  You absolutely have to have a base line in order to run down issues.  Having a fresh set of test tubes allows you that capability.

If the new tubes have the same issues it is probably a cold solder joint. 

Simply get your iron hot touch the lead tip, and hold the solder against the opposite side of the lead.  When the solder melts you know its hot enough. 

Its weird how a cold or cracked joint can cause significant noise issues in both solid state and tube gear. 

But having new fresh tubes for current and future testing is a great starting point.

Cheers!

[david62]

Jim,

  It turned out to be a JJ tube,which eventhough it is new,became noisey.I put in a set of clear tops and the noise went away.
Dave

[Bill Epstein]

I have a pair of RCA Cleartops left from wayback when I built my first kit: Foreplay. Highly recommended, they just....were.

Further down this road I decided they weren't for me; kinda cold and sterile. YMMV.

I'm a big RCA fan but now have a JJ 12AT7 driving the 6CA7s in my Simple SE and Sylvania black plate green label 5965s driving the RCA Cunningham 45s in the other amp.

RCA blavk plate 5963s are doing a 'straight wire with gain' job in my Clarinet currently. I've been switching between carts and phono stages recently and the Clarinet reveals every nuance of the changes.

Who's good at math? 2 cartridges, 2 phono stages, one pre-amp and 2 main amps; how many possible combinations?

[david62]

I can tell you that the clear tops have more base line hiss than the JJ tubes did,but that may be due to their age.I plan to try some Amperex tubes next as soon as my friend can get them to me.I still need to re-connect the teflons bypassing the SOL caps in the output stage...At least the static is gone.
Dave