Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: adejacko on February 24, 2013, 03:43:37 PM

Title: 6DN7 tubes in UK
Post by: adejacko on February 24, 2013, 03:43:37 PM

Hi all,
Have just completed a S.E.X. amp with impedance switch (1st build). Only one problem, there's a low humming sound from one of the tubes. I know it's the tube as the hum changes channel when swapped.

I cannot find replacement 6DN7 tubes anywhere in the UK. Can anyone please help?

Title: Re: 6DN7 tubes in UK
Post by: andrewuk on February 24, 2013, 08:53:06 PM

I've got them all!!!!!!!!!!!!!!!!!!!!!!! - howls of maniacal laughter ;-)

& I have a lot of 6FJ7s which are the 12 pin equivalent.

Title: Re: 6DN7 tubes in UK
Post by: audioengr on March 05, 2013, 08:37:39 AM

I have some spare NOS GE 6DN7s.  I can ship them to the UK for about $16 using priority mail.  email me at [email protected]

Steve N.

Title: Re: 6DN7 tubes in UK
Post by: andrewuk on March 05, 2013, 10:42:49 AM

Oh perhaps I was flippant - its just how I am; apologies. If you look on eBay I expect you will find 6DN7s. The USofA has millions probably. They were originally line output valves for colour televisions - very very linear so superb for our purposes! Clolour Tellys quickly went solid state so 6DN7s were surplus stock. But I really do have 'a few' and if you want a couple , okay, I can spare them.

But if you stalk ebay you will be able to pick them up at a good price even though English customs and VAT are a kick in the guts.

Good luck, !

Title: Re: 6DN7 tubes in UK
Post by: adejacko on March 27, 2013, 03:30:32 AM

Thanks guys,. Eilleen from Bottlehead sent me some new tubes, but I still get low humming sound. It went away for a while, the amp was completely silent, then the humming came back in both channels. It's inaudible when the volume is turned down, and increases as the hum pot is turned up.
Any ideas?

Title: Re: 6DN7 tubes in UK
Post by: Paul Birkeland on March 27, 2013, 04:53:51 AM

Quote from: adejacko on March 27, 2013, 03:30:32 AM

It's inaudible when the volume is turned down, and increases as the hum pot is turned up.
Any ideas?

This is external interference, tell us more about your source(s) and cabling.