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

Showing 1 response by elevick

elevick
2,636 posts
 
I always test tubes before installing.  If they test "new" then fail 2 months later I would be very inclined to have my pre-amp checked out.  4 tubes going bad at once is very unlikely unless your pre-amp is burning them up.  Keep in mind that your new production tubes may simply be more durable?

czarivey-I've never heard of bringing tubes up to voltage on a variac?  What's the point?  It's like turning on a light bulb with a dimmer switch only.  Yes, if the pre-amp spikes the voltage upon turn-on you can damage things.  That's why this pre-amp probably needs to go into the shop.
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