Looking for thoughts/opinions on tube seller's response to my question...

Hi All!

I recently bought 4 balanced and matched reissue Tung Sol 6SN7GTB preamp tubes from a guy that I've bought 3 different sets of tubes from in the past (with no previous issue). 

I rolled out the early Russian tubes that came with my Schitt Freya and rolled in the new Tung Sols.  Immediately in system idle there is more noise in the form of hiss, scratchy air, etc.  I ran the Tong Sols for maybe 15 hours or so. No change. 

I emailed the seller to which he responded: 

The 6SN7GTB can take a break in period in some applications. If you Google you will see this phenomena is common. Run them in your equipment for 24 houts and re-evaluate. New ones I exchange would have the same break-in period. The factory has indicated it has to do with the cathode coatings used to extend tube life. No problem returning them if the problem persists.

Have you heard of cathode coatings causing this issue?  While I generally like NOS tubes a bit better than reissues, I've never had a new noisy reissue tube.  Also, I really do like purchasing tubes from better stocked places like Upscale Audio because this issue never seems a problem. But when it comes to new reissues, I don't look first to Upscale.  Maybe I should? 

I'm running them in to see what happens.  I'm not optimistic though. 


Showing 1 response by newf27

Have purchased perhaps 100 tubes for my two tube pre-amps and two tube power amps during the last 18 months.  Purpose is to inventory a stockpile good til I die since the price of NOS keeps climbing.  Of these, three (3) were noisy with crackling, creaking, or microphonics. I feel the only arguement acceptable for “breaking in” tubes is to allow them to mature to sound better.  It seems like the seller may be hedging that replacements from his shop could repeat the problem.  Flag.  If they are cracking/creeking out of the blocks I would consider that a defective tube or indicative an inferior manufacturing process.  In my case, sent them back for a refund and moved on.  Its good your seller offered up front to accept a return.  Good suggestions in previous responses where to find reliable tubes.