NOS tubes for Sonic Frontiers Line 1

I just experienced my first NOS tube failure. One of the Siemens early 60s CCa tubes. The bad tube was installed in the center row of the line one, V2, right channel.

Here is what I experienced. When switching line inputs from the front panel I got a popping sound through the right speaker. Scared the hell out of me to say the least. Also up close I heard a slight fuzzy sound comming from the right speaker. I had pulled the CCa tubes earlier and installed a pair of early 60s Siemens E88CC I had just received. I listened to the E88CC tubes for about an hour and a half. I pulled the E88CC tubes and reinstalled the CCa tubes. I powered back up the Line one, when I pushed the line input for my CDp, thats when I heard the pop... Like a dummy, I pushed one of the other line input buttons to confirm what I had just heard...

I pulled the tubes one at a time and tested them. The bad CCa failed in section 1 of the dual triode tube. Section 2 still tested strong. The puzzling thing is section 1 does not show any shorts or grid emissions. I did not take a listen after the problem, I did not want to take any chances of damaging something.
This tube was from the last pair of CCa tubes I had just bought. I had maybe 150 hours on them.

I then reinstalled the early 60s Siemens CCa tubes that I had installed in the back row, and installed them in the center row. For the back row I installed the Siemems E88CC I had received today. Powered up the Line one, no pops when switching the line inputs system sounds fine.

Any thoughts? I handle the tubes like a new born baby. This is a first for me with an NOS tube.

Jea,

I know this answer is late to your original question but I used to own a Line 1 which I purchased from Kevin at Upscale Audio. At that time I had asked Kevin for some NOS tube recommendations for it. He suggested an Ediswan 6922 from the 1960's and I purchased a pair. I tried tons of different tubes in my Line 1 but kept putting the Ediswan back in. Ediswan are hard to find on the used market but if you every get a chance, try a pair, they were very good IMO.

Good Luck and sorry for hear of the CCa failure, a hazard of the hobby.

Mike.

I just replaced the 6922's (all 6) in my Power 2 amp. I put EH 6922 Gold Pins in there, to replace Siemens NOS ECC88's. The EH tubes sound a bit darker, but the bass is much better. I miss some of the openness in the midrange and treble with the Siemens, but I'm very happy with the EH, nonetheless. It's good to find a tube you can be happy with that is also in abundant supply, IMHO.

Also, I can see unequivicolly that the EH Gold Pins are far superior to the standard EH 6922, which was the stock tube in my Blue Circle pre-amp.

Cheers.

I finally got around to buying a pair of early 60s USA made Amperex PQ 6922 tubes. Both tubes were made in 1961.

Another great tube. Not quite as warm as the early 60s Siemens CCa tube but still a very smooth sounding tube. The 6922 PQ is detailed, fast, lots of air, and liquid sounding. Imo the bass is deeper than the Siemens CCa tube. The sound stage is wide and multi layered.

In an earlier post I mentioned the early 60s USA Amperex 7308 tubes. Imo, in my system, the 6922 PQ is a better sounding tube. Vocals are more involving.

My present tube placement in my Line One

Back row early 60s Siemens CCa
Middle row early 60s 6922 PQ USA
Front row early 60s Siemens E88CC

Audio Research VT50 Amp
All "EH"

In my last post I forgot to mention I found the best position for the Herbies HAL-O damper was near the top of the 6922 PQ tubes.. In fact I run the HAL-O dampers near the top on all the tubes in the Line One.