[Deleeh]

Who was it that had problems with the Gec KT63 a few weeks ago where they came from Langerex?
Did you receive them and could you listen to them?

I've just got them in with a 6bw4 and 12AT7 Rca JRC and the new cap and they sound absolutely magical with the Zmf's headphones.
Had a 5hr session with the Auteur Og today could only enjoy it and have pleasure.

 

[crakers7]

Who was it that had problems with the Gec KT63 a few weeks ago where they came from Langerex?
Did you receive them and could you listen to them?

I've just got them in with a 6bw4 and 12AT7 Rca JRC and the new cap and they sound absolutely magical with the Zmf's headphones.
Had a 5hr session with the Auteur Og today could only enjoy it and have pleasure.

That was me , I received the replacement but Langrex ran out of the the GEC Black glass and so sent me a grey glass , I am not sure if they are exactly the same tube internally but they look to be . Hopefully they are OK to be used together , I will try later today and let you know.

 

[Deleeh]

That was me , I received the replacement but Langrex ran out of the the GEC Black glass and so sent me a grey glass , I am not sure if they are exactly the same tube internally but they look to be . Hopefully they are OK to be used together , I will try later today and let you know.

Should not be a problem.
Not quite as attractive visually, of course.
I have 3 pairs, one of which also looks like yours.
I found another pair on Ebay for €30 each at the time.
They were from a private seller in France but with grey glass.
I'm curious what you'll say about them later.

 

[crakers7]

Should not be a problem.
Not quite as attractive visually, of course.
I have 3 pairs, one of which also looks like yours.
I found another pair on Ebay for €30 each at the time.
They were from a private seller in France but with grey glass.
I'm curious what you'll say about them later.

They sound wonderfull , great tone , base is good , vocals sound excellent , however there is a difference in the balance , the vocals shift to the left and the left tube is biasing at 39mA and the right at 35mA . It's a shame as apart from that they sound excellent . I will look for another GEC KT63 that matches one of them .

 

[Deleeh]

They sound wonderfull , great tone , base is good , vocals sound excellent , however there is a difference in the balance , the vocals shift to the left and the left tube is biasing at 39mA and the right at 35mA . It's a shame as apart from that they sound excellent . I will look for another GEC KT63 that matches one of them .

Let the tubes run for a few hours, I have read where you have tested that the electrical part changes again most of the time after the tubes have been running for a few hours it seems to stabilise a little.
The right side of the tubes I'm using are slightly louder when they're cold, but when they're warm it gets better, but swapping them from right to left can help.
The tube otherwise sound really good.

 

[crakers7]

Let the tubes run for a few hours, I have read where you have tested that the electrical part changes again most of the time after the tubes have been running for a few hours it seems to stabilise a little.
The right side of the tubes I'm using are slightly louder when they're cold, but when they're warm it gets better, but swapping them from right to left can help.
The tube otherwise sound really good.

OK , I will leave them to run in and see if they change

 

[crakers7]

Yesterday I tried my EL81 tubes in UltimatE , with both pairs the mA went up to around 70 and I got very loud hum , it was unlistenable . Can anyone explain what may be the problem ?

 

[Nick Ryan]

Yesterday I tried my EL81 tubes in UltimatE , with both pairs the mA went up to around 70 and I got very loud hum , it was unlistenable . Can anyone explain what may be the problem ?

It won’t help you but my Tesla EL81 are as silent as the night. Clean all,of the pins with wire wool or sandpaper and the top cap, try again.

 

[crakers7]

It won’t help you but my Tesla EL81 are as silent as the night.

yep , its really weird , I wonder if its the adapters ? Not sure how to diagnose the problem

 

[Deleeh]

Have you already recorded them or are they still new?
I don't know if 70ma is much, but since you have it with both pairs you could be right about the adapters, if the 70ma are okay in terms of value.
Eric may be able to help.

 

[crakers7]

Have you already recorded them or are they still new?
I don't know if 70ma is much, but since you have it with both pairs you could be right about the adapters, if the 70ma are okay in terms of value.
Eric may be able to help.

I think its some sort of ground fault in the adapter, when i touch the top cap on adapter the loud hum disappears , also when a multimeter touches the test points the hum comes back and mA goes up to 65-70 , tubes got very hot also . Removed the EL81 from amp and will order some new adapters from @Deyan

 

[Deleeh]

Ahh, that's annoying.
That's exactly why I don't like buying from Mrs X, I'd rather spend the extra 5-10$ at Deyan for reliable adapters.
Maybe Eric can fix it if you bring it to him or send it to him, since you live in Australia that might be possible.

Edit: It would probably not be advisable to continue using these adapters if they cause problems.

 

[Deyan]

Yesterday I tried my EL81 tubes in UltimatE , with both pairs the mA went up to around 70 and I got very loud hum , it was unlistenable . Can anyone explain what may be the problem ?

The EL81 is notorious for being prone to selfoscillate.

 

[Deleeh]

The EL81 is notorious for being prone to selfoscillate.

Can you explain what that means for a loan?

 

[Deyan]

Can you explain what that means for a loan?

Basically the thing @crakers7 just described, something is acting like an antenna in your setup and the tube resonates out of control. The EL3's tend to do the although not that often. Before I started building adapters I used to resell tubes, my tube tester was something that I built myself and when testing an EL3 I had to switch it on and get 3-4 meters back, or the same thing was happening. One can try putting ferrite filters on the cable for the top cap, they probably won't help as the plate is on top, but still worth the effort.