Sounds like a stylus on the paper label

[garrardfisher]

Has anyone has ever noticed this particular sound?  The
seduction started out quiet for a month or two after the build,
but now has an itermittent noise that can be temporarily cured by
tapping on the top plate, so I suspect it's a joint.  The sound is
much like that of a stylus crossing onto the inner record label, but
softer and staccato and sometimes it has a pattern as in it fades away
by going from pop pop pop to pop....pop...........pop.........   

It's only in one channel and I've eliminated tubes and interconnects. 
It is definitely the left channel circuit.  I have also reflowed
the solder twice on every joint on the left channel.  I have not reflowed the
solder elsewhere, and I haven't reflowed the common ground plate. 

Is it possible that a component could have been overheated from the solder iron, or is it
definitely a broken joint that I'm just missing?  I'm new to tube gear, so I am not familiar with
all the odd sounds they can make.

Any suggestions appreciated!

[Doc B.]

Could be either a tube or, somewhat less likely, a cap. Did any of the caps get nicked by the soldering iron?

[Grainger49]

The easiest thing to do is clean the tube pins and the socket.  Read Question #2 in the FAQ Thread.

[earwaxxer]

Sounds very much like a tube sound to me. A worn out carbon pot sometimes sounds like that when the volume is turned up or down.

[garrardfisher]

Could be either a tube or, somewhat less likely, a cap. Did any of the caps get nicked by the soldering iron?

No caps were nicked, but towards the end of the build, I had to use some 96% silver solder, which is tough to work with.  It may have caused me to overheat some of the components.

I will try cleaning the socket because I swapped tubes and the problem stayed with the left side.

Thank you for the suggestions.

[2wo]

Yow, 96% no way that will work, short of using a torch. Pick off any loose bits, then as there is silver involved. Get some 2% silver electronic solder. The Kester 2% is excellent, and hit those  connections again...John   

[Laudanum]

I would go with Johns advice, re-wet with a 2% silver lead based.   But Im assuming a 4% silver solder was used.  Ive never even seen 96% silver content solder.   
96% Tin / 4% Silver is a bear ... basically plumbing solder but also seen it sold as lead free electronics solder.   
Lead based 4% silver is do-able.  I have a small container of it and it's not too bad but I stick with my 2% Multicore if Im using silver solder.

Anyway ... +1 on what John said.      

[Grainger49]

He mis-typed.  It has to be 4% silver, 96% whatever.  We used silver solder for thermocouples at Alcoa.  They had to be assembled with an oxy-acetoline torch.

[garrardfisher]

Well, thanks again for the advice.  I really appreciate you guys taking the time to give some input.
And yes, I definitely mis-spoke on the percentage of silver in my solder.  I've not done much
soldering in my life, so I'm not good with the terminology.   

I wanted to check back in and give a status.  I think I may have located the problem. 
I re-wet the solder on one of the snap-in power supply caps that
are difficult to reach and therefore I probably didn't solder them sufficiently the first time.

I'll keep ya posted if the issue comes back (like it did once before), but I think I got it this time.