[mordy]

Sometimes the noise and hum is due to corrosion on the pins so I suggest that you clean them. I use fine sandpaper.
And sometimes the noise and hum is due to sitting unused for 60 years or so. If so, they might quiet down after burning in for several hours.

Except for cleaning he pins and letting the tube burn in I have not yet found a cure for persistent loud crackling and popping after giving the tube time to burn in. However, I have found that using inexpensive high temperature self sealing silicone tape around a tube can cut down or even eliminate hum.

 

[mordy]

None of the single pentode tube adapters for Feliks amps will work.
This will work
https://www.ebay.com/itm/1pc-Gold-D...623692?hash=item2cb7a5490c:g:aC4AAOSwJ7RYW8eI
You can also use this on the outputs if you stagger them. Don't know how it will sound the impedance of these tubes might be to high.
Maybe with high impedance phones? But you will need 4 of these tubes and 2 adapters just to try.

It sounds too complicated and expensive to try. Since I am very happy with the tubes I have and use in the GOTL, I think I just have to let go of the idea of trying these tubes.

 

[wkahwkah]

Except for cleaning he pins and letting the tube burn in I have not yet found a cure for persistent loud crackling and popping after giving the tube time to burn in. However, I have found that using inexpensive high temperature self sealing silicone tape around a tube can cut down or even eliminate hum.

Hi Mordy, do you have recommendation or link for the silicone tape? I have couple of tube that hums, especially 6BX7. I would like to try to see if it helps with hum. Thanks

 

[mordy]

Hi Morday, do you have recommendation or link for the silicone tape? I have couple of tube that hums, especially 6BX7. I would like to try to see if it helps with hum. Thanks

Hi W,
You can try this:
ttps://www.ebay.com/itm/2-5-150cm-Waterproof-Silicone-Rubber-Repair-Tape-Bonding-Rescue-Self-Fusing-Wire/232451464568?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

They accepted my offer of CAD2. If you don't have the patience to wait for an order from China, you could find it in places that sell automotive supplies; it will cost perhaps $6 for a roll.

It looks like a roll of a little thicker electrical tape. Roll out a piece and fit it around the tube. Then mark off the circumference and cut it off about 1/2" smaller than what you measured. Peel off the see through backing and attached that side to the tube. The tape is stretchy, and after sticking it on the tube in one spot, pull on it until it is tight and overlaps the ends. Press together and it glues itself together.
I found that it actually helps for hum, either reducing the hum to a tolerable level, or eliminating it. YMMV.

This is a cheaper alternative to the expensive silicone rings that you can find from various sellers. This tape supposedly works better according to one source.

And if it doesn't work, you could always use this tape to fix a leak on a pipe or automotive hose....

 

[attmci]

There is a German seller that sold EL12 tubes as NOS at a high price. Angpsi is now selling off his tubes and had them measured and double checked. On a scale of 0-100, the "NOS" EL12 tubes measured 36 and 12 respectively. This may explain why UT had so much trouble with his EL12 tubes bought from the same seller.

Come to think about it, any recommendation for an inexpensive tube tester that will do the job?

On the other hand, I get the impression from my reading that test results may not indicate the true condition of a tube. In other words, a tube may measure well and still be unusable because of noise and hum. True?

Very true. If you have more than, say 6000 tubes, you'd better get a tube tester.

 

[UntilThen]

Very true. If you have more than, say 60 tubes, you'd better get a tube tester.

I guess that's me.

Now I need some advice from those in the know. Are these testers any good?

https://www.ebay.com.au/itm/Valve-T...338938?hash=item468653a33a:g:xhEAAOSwnhJbre77

https://www.ebay.com.au/itm/Valve-T...665286?hash=item4684ea6806:g:-4cAAOSwn6RblcMZ

 

[UntilThen]

Today the sound from my setup is crisp, sparkling and very refreshing. I am in love with this tone. Yggdrasil pair very very well with the Glenn OTL and the HD800, what can I say. Details, soundstage, dynamics and transients are top notched.

Not forgetting Audirvana 3 plus

 

[2359glenn]

Very true. If you have more than, say 60 tubes, you'd better get a tube tester.

Tube testers don't test the tubes at true operating conditions might test good and still be bad.
Try to get NOS tubes and take the risk try to buy from a reputable dealer instead of E-Pay

 

[attmci]

I guess that's me.

Now I need some advice from those in the know. Are these testers any good?

https://www.ebay.com.au/itm/Valve-T...338938?hash=item468653a33a:g:xhEAAOSwnhJbre77

https://www.ebay.com.au/itm/Valve-T...665286?hash=item4684ea6806:g:-4cAAOSwn6RblcMZ

No Matt. That's Mordy.

BTW, where is our friend, Stavros. He collects tube tester, and can give you better suggestions.

I have no idea of these two tube testers.

 

[attmci]

Tube testers don't test the tubes at true operating conditions might test good and still be bad.
Try to get NOS tubes and take the risk try to buy from a reputable dealer instead of E-Pay

Tube tested bad are always bad.

 

[gibosi]

Very true. If you have more than, say 60 tubes, you'd better get a tube tester.

I've got something like 2000 tubes (including a bunch for the Little Dot), most from eBay, and while I think it might be nice to have a tube tester, I'm not sure that getting a good one, that is, one that has been rebuilt and tested, is worth the money. After all, I already have a superb tube tester:

If it works in the GOTL, it is good. And if it doesn't work in the GOTL, it is bad. End of story. lol

 

[UntilThen]

As I walk along the beach, I am wondering who gave me the idea to buy a tube tester !!!

 

[attmci]

I've got something like 2000 tubes (including a bunch for the Little Dot), most from eBay, and while I think it might be nice to have a tube tester, I'm not sure that getting a good one, that is, one that has been rebuilt and tested, is worth the money. After all, I already have a superb tube tester:

If it works in the GOTL, it is good. And if it doesn't work in the GOTL, it is bad. End of story. lol

2000 tubes (BTW, I had to modify my previous post. LOL The "60" should be read as "6000")? How about this?

https://www.ebay.com/p/Hickok-539C-Tube-Tester-Fair-Working-100/1001736320?iid=192540450182

 

[gibosi]

2000 tubes (BTW, I had to modify my previous post. LOL The "60" should be read as "6000")? How about this?

https://www.ebay.com/p/Hickok-539C-Tube-Tester-Fair-Working-100/1001736320?iid=192540450182

That model would work for most of my tubes. However, $1800 isn't cheap. And even though the seller claims it works, I would still want to have it checked by a technician, so that would be an added cost. But I also have something like 50 European 4-volt rectifiers with four different bases. Perhaps there is a way to test these with the Hickok using adapters? I certainly don't know. So I might need two testers? Or perhaps one of the better European testers can test all my tubes? Regardless, I think I will wait until I win the lottery. lol

 

[attmci]

That model would work for most of my tubes. However, $1800 isn't cheap. And even though the seller claims it works, I would still want to have it checked by a technician, so that would be an added cost. But I also have something like 50 European 4-volt rectifiers with four different bases. Perhaps there is a way to test these with the Hickok using adapters? I certainly don't know. So I might need two testers? Or perhaps one of the better European testers can test all my tubes? Regardless, I think I will wait until I win the lottery. lol

http://tone-lizard.com/category/tube-testers/

There is a summary of various tube testers somewhere on this site.