2. analog
  3. 125078-1452

Bad NOS tubes...

I just want to put this out there...as much as I would not like to...my head says otherwise. Tube buyers beware!!!

On 3/7/16 I bought 6 NOS Mullard 12au7 4003 tubes for my preamp from a vender out of Minesing, Ontario Canada... under the store front name of ’mullard.com’ http://www.mullardtubes.com/Mullard-ECC82-12AU7-CV4003/?ID=0&ProductID=153 and ’ tube products.com’ http://www.tubeaudioproducts.com/Mullard-Brimar/ProductDetail.aspx?CatID=65&ProductID=153#

The owner is one Alfred Kayser. On his site/sites he states all of his tubes are tested and matched for best performance values. Well,I went ahead and ordered and received said tubes. After 2-3 months of use I started to hear unacceptable levels of noise from my speakers,you know, the dirty sound of that dreaded tube noise of a scratching, distorted, dirty volume pot type of noise,which totally infringes upon the music. I went ahead and called Alfred and asked him about it and he just responded there is "nothing he could do" for me. Hey,no problem,but he advertised full-up tested tubes. If it was only one bad tube,I could understand,I’m a realist...things happen.

But!!!

Long story short,I came to find out that four of the six tubes are defective and are not what I paid for. Two are fine. So the moral of this story is...When buying tubes,do not go the cheaper route,find and use a "reputable" tube vender and save yourself some time,money and aggravation. Of course I will never use this guy again for any of my audio needs... Hope this is of some help to the Audiogon membership.

aolmrd1241
aolmrd1241 OP
1,042 posts
 
Jea48 asked...

Did you clean them?....Yes I did.

When were the tubes manufactured?..... I don't know the manufacture date.

Gold plated steel pins I assume?..... Steel pins,no gold plating.

How tight do the pins of the tubes fit the tube socket female contacts?.....Extremly tight.

Did your tubes come boxed like this?..... Yes.

lewm
13,090 posts
 
Jea48, Gold-plated pins are a sure sign of recently manufactured tubes.  Vintage tubes of the good old days rarely had gold-plated pins unless specified by the type. For example, some milspec 6900s had gold-plated pins but most did not.  GE 5-star tubes sometimes had gold-plated pins. Other than those two instances, I have never encountered true vintage tubes with gold-plated pins.  And the pins are not usually made of steel.  They're probably brass or other copper alloy (which is why they oxidize and may need cleaning) or rolled "sheet metal" in most cases, although which tubes have what pins is an interesting question.  Just not steel.
mcgowdog
18 posts
 
I agree with the op.

I bought a refurbished set of Mark iiis that came with nice new Tung Sol 6550s and I had bought a nice old Pas 2 from Gold Sound on South Broadway in Denver (Englewood technically ), and it sounded really nice.

I got some nice nos EIA 12ax7s from my brother for the Pass 2, a nice NOS Hammond  driver tube and nicely matched Svetlana 6550s for my mark iiis, and wow.  

Not that it sounded like mud before,  it really didn't. 

As far as the nos vs brand new tubes, I'm not going to dog some audiophile's religion. I just don't have the time.  Let YOUR ears be your guide.

I also hear that really good nos or highly tested used old stock tubes last way longer than the new stuff.

So there's another opinion for ya, based on my own experience,  of course.
jea48
4,442 posts
 

lewm,

Here is some reading material for you.

http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8


Post removed 
More to discover