What do defective phono tubes sound like?


I have noticed some rather loud energy discharges when playing LP's.Sort of an abrupt popping.Not unlike static discharge.I do not get this with my digital playback.
The ONLY change made to my system lately has been a new arm.The problem began immediately "after" it's installation.It was just fine with the previous arm.

I don't want to make this an "arm" mfgr thing(and will not mention arm name)but wonder if the phono tubes in use(very NOS Siemens CCa's,with low hours)can be the culprit.

This is making me pull my hair out,and I have little already.
Any thoughts would be appreciated.
sirspeedy
Thanks to all,so far.Originally the problem blew a fuse,and cap in my table's electronics.Got a brand new table(Sota is an amazingly fine company to deal with,and really care about their customer base....BIG TIME).
I spoke to my arm supplier,and was met with sincere concern,but I simply cannot believe my luck is SO bad,that it is arm related.The cable is not played around with alot,and I am very careful about stuff like this.Ditto for the tube sockets!

My frustration is that my friends all know just how fanatical I am about proper maintenance,and component care.All is plugged into an Exact Power EP-15a/Ultrapure,which seems just fine.My CD player plays perfectly.

Of course "now" the pricey(yes I have quite a few back up sets)NOS Siemens tubes are "very suspect",but I am really beginning to feel "worn out" from the diagnostics.I have really sweated alot over this latest fiasco!

Mainly since I have a business,and don't have alot of time(in this economy) to frigg around with such expensive stuff.Actually,I have played around SO much in the recent past,that I just want to get back to normalcy again(like hearing LP's)....."Will this ever happen for me"?That's what I have started asking myself,as I have spent a load of bucks,and time on the hobby as of late,and am feeling the New York Jets curse.

My CD sound is consistent though,so I do have music,but "MAN" I now have such great analog stuff,and I keep running up against this damn roadblock of noise/sudden discharge.In a dedicated room,with dedicated lines yet!!OOOOOHH!!!!Frustration!

I have decided to take off Tuesday,and roll up my sleeves,for some real(dreaded) diagnostics.Tube swaps will be on tap,but it "does" seem odd the problem began the instant the new arm arrived.....Hmmmm?

So,right now it can be a few different things...tubes(hopefully),one of my power cables(doubtful),the arm cable(doubtful),a line conditioner(aren't these supposed to stop this kind of stuff?),phonostage(I would not really mind this,as I would then upgrade to new Teflon caps,so I'd probably be ahead of the curve).Or the new arm itself,but "that" would be a new one to me!!

Now I know why I've been looking hard at the Acoustic Guitar mags as of late(used to be a flat picker).Those limited edition Martins look SOOO nice.....We'll see!

Best to all.
Why not replace the old arm and see what happens. If the problem (popping from the speakers?) remains, then the new arm is most likely not the problem.
But, if your back to vinyl heaven, then perhaps it's time to deal with the new arm.
Hang in there. Keep us posted.
Dear Sirseedy, very strange you post this problem now, because I have the SAME problem occuring recently, and we have quite similar systems ! I am also on the diagnosis pathway, and I never thought of a tube problem . I swapped
recently the 12AX7A NOS Telefunken for military grade Mullards , and wonder if they are the culprits.It is like a big electrical discharge occuring every 10 minutes, but only with my analog system . I borrowed a PS Audio Premier Power plant and proceeding by elimination, apparently it is the phonostage headamp who is picking up AC noise when my REFRIGERATOR switches on. When I unplug the frig this not occuring anymore. Hope this helps.
Another possible source is the unshieled proximal part of the tonearm cable, Purist Venustas in my case, hooked to Graham Phantom, being too close to phonostage and picking ground loops and discharging loud pops. When I separate the tonearmcable from phonopreamp the noise and pops disapear
SirSpeedy,

Any chance it's mistracking? (I know you'd have recognized that, but thought I'd cover all the bases.)

Diagnostic question: do these pops happen in both channels or just one?

I'd put a small wager on a loose connection at the cartridge pin(s). Check those carefully for tightness and clean the pins and clips. For cleaning gold, see the last paragraph.

We had a similar LP-only problem last winter, in the R channel only, which made diagnosis easier. Turned out to be slightly spread connectors in one pin holder of one tube socket in the phono stage. I tightened the two clips carefully with a fine tweezers and the problem was resolved. So when you pull your tubes check the connectors in each hole before reinstalling, and clean all the pins and pin holders of course.

For cleaning gold connectors Paul recommends (and we use) a very gentle rubbing with a paper towel. Nothing stronger or more expensive is needed, nor does it require any chemicals. Gold oxidizes in a layer that's basically one molecule thick and it only takes a gentle buffing to remove. Do NOT use a Magic Eraser! ;-)

Good luck,
Doug