Bad Tubes?

hochpt21

I got some Mullards for my Dared a bit ago. Tried them 3 or 4 times and very microphonic. Like I was getting microphone feedback some of the time. I pulled them out and tried some other tubes. I was going to wait to try the Mullards again when I got some tube dampers.

I finally got some tube dampers and tried the Mullards again...first bare without the dampers. I immediately started getting a horrible sound kind-of like white noise. It was not the old microphonics, but a horrible sound. It wouldn't stop even with the volume all the way down, so I turned off the unit.

I then swapped in some other tubes and they worked fine.

I then tried the Mullards with the tube dampers and got the same horrible white noise.

I then tried another separate pair of tubes and no problem.

I'm a tube noobe so please help me out.....are the Mullards garbage?

Thanks,
Paul

hochpt21

bump

hochpt21

Thanks Keiko.

Anyone experience the wicked white noise I was hearing?

headrott

Are these NOS Mullards or the newer production (from Russia)? Did you get some readings with the tubes when you received them? If so, what are they?

The newer production tubes should not be microphonic. The NOS tubes (for how old they are) could very well be microphonic or just "spent".

pitdogg2

If they have a dish/UFO getter = built by Russia. I had some of the 70's Mullard 6ak5 tubes and they mucked up to say the least. I had to turn up my volume knob to the 3 o clock position to get sound out of my tube buffer. Seller who I trusted well told me to send it back for refund but did state that it tested NOS twice once before the sale and then right before he sent them. Anyhoots I'd stay away from any Russian built Mullards. From what the seller told me " Built by Mullard with all Russian parts" So buyer beware to say the least...

hochpt21

Mullard ECC81 long arm D getter tubes

^^^^^This is the info I know off hand^^^^^

I can check for more when I get home. Very trusted seller.

Has anyone experienced that white-noise junk by chance? As soon as I turn the Dared on, the noise starts in fairly loud even with the volume all the way down. I just have to turn the unit off as quick as I can.

pitdogg2

Sometimes even the best of the best do not mesh with our gear. Make a note of it and move along to the next.

unless the seller would like to send out more of the same so you could make sure I'd just move along. Sounds to me like a tube thing as much as we would like to have the best of certain tubes sometimes they just do not work out.

hochpt21

Thanks pitdogg, maybe I'll let a buddy try them and see if he has the same results.