What do defective phono tubes sound like?

The one easy thing about trouble-shooting tube gear, is the ease to swap out tubes as a first check for a problem. What you describe is very much what I recently observed with a phono stage (ARC MCP-33) power supply tube. There were loud pops and other times it was an oscillating upper-bass tone. When it happens it can really make you race out of your chair! A quick tube swap and it was gone. A day or so later I put the suspicious tube in and the problem was back which confirmed this was indeed the problem and in the trash that tube went.

Another thing to consider here: since this is a new tonearm, there may now be an intermittent connection. Is the cable attached or the same you used before? Removing these can result in weakening the connection, especially at the din. If the level is high and the connection is intermittent this could cause any link in the chain to cause a "spike" but generally more of a hum.

John

I can tell you for a fact that just becuase they are NOS tubes ,does not always make them NOS..Ocassionally you can receive a tube that tests well at the supplier,but for some reason the tube does not survive the ageing process and you will get Spitting or Sharp distortion noises etc..I recently had to send back a nice pair of NOS Tungsram 12ax7 due to this same situation..I am not in anyway saying this is your problem..Only saying its possible it is..Trying flip,flopping tubes and see if you noise travels with positioning...Also sounds like it may be a Static Electricity problem ..Good Luck

yes to the above posts, but also, get the tubes out and clean the sockets and tube pins. I had an Audio Research unit whose sockets and tube pins had to be cleaned, and the spitting noise was no more.

Sirspeedy
Do you have back up pairs you could plug in and try first of all?

I'm sure whom ever you bought your gold pin Siemens CCAs from is someone you trust to deliver as advertised?

Re-test the CCAs.

It could of been coincidence this issue occurred just when you switched tonearms.

These are vintage electrical devices, sometimes they will develop problems quickly with a current flowing through them once again.

Also , I,m not suggesting you do this.
Some guys constantly roll tubes. The sockets were not ment for this.
But if you do!....Have a tech check them out

Good luck....

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.