[PETE6737]

Hello All
I'm new to tubes and I just received my Oppo Bdp 105 Modwright mod back. I'm breaking in the tubes and one tube has a piece of metal that is not like the rest and glows brighter. I was wondering if I need to worry about that. As a side note, I have Sophia's and a Phillips rectifier waiting to be installed after the break in. Thanks in advance, Pete






It looks like three prongs are flat and one is rounded.

[dminches]

Is that the stock EH 6SN7?  If so, I would replace it since it isn't a very good sounding tube.  You can get something for under $100 per pair which will sound much nicer.

[PETE6737]

 Yes, it is the stock tube. I have some Sophia tubes waiting to be installed.  The suggestion was to put several hundred hours on with the stock tubes before changing out to the better tubes and the new Phillips rectifier tube.

[mca]

dminches,

What do you suggest as a replacement in the $100 range?

[Bill Baker]

My guess is that if you wait to.install your new tubes, you will have to wait for those tubes to break in starting all over again. I would think you would want to break in the component and tubes together. Signal tubes last a long time.
Good.choice on the Sophia tubes by the way.

[PETE6737]

Ok. I'm going to install the Sophia's when I get home. Thanks

[JackD]

mca

Contact Andy at Vintage Tube Services.  Tell him what you are putting the tubes in, a budget and he will find you NOS tubes that will fit what you need. I'm not a fan of the new Far East or Russian tubes and there are still many NOS tubes that can be bought for less.

[jriggy]

Pete6737,

You may know this but since you say you are new to tubes. One of the reasons for leaving the stock tubes in place through break-in and further is to get to know the sound of your new piece of gear, so when you begging trying new tubes you have a baseline to compare them to. With that said, the Sophia's are great in Dans designs. Or breaking with the stock tubes so's not put those hours on the Sophia's . Either way is a plus. OR don't be afraid to swop at will! But some say these tubes need a hundred hours or so of burn-in themselves.

[G Georgopoulos]

the tube glows points to heaters of the tubes,try replacing the tubes and see if the glows are balanced,if not,then i would assume you have some kind of fault with the heater circuitry...not tube fault...hope this helps.

[sfox7076]

6SN7 is not center tapped, so the heater circuitry should not heat one side more than the other.  I suppose there could be some issue if it is not pushing enough current, but I doubt it.  More likely a not so well made tube.

[Bill Baker]

If it sounds okay. I would not worry about it. It is often just different positioning of the heaters. They are likely performing as they should. Lots of tube will have a different visual effect when viewed.

[G Georgopoulos]

or a different heater filament material...

[PETE6737]

Thanks All,

The brighter tube element in the pic is clearly rounded off and has a tiny hole in it like a half of a donut. The others are flat. The pic wasn't the best to show it it clearly.  My original post about the brighter tube seems like it's a manufacturing thing, and in my mind,the extra rounded metal on the top probably wouldn't affect anything, but I wanted some confirmation on that  ...Regardless they are being replaced by the Sophias at some point..

"You may know this but since you say you are new to tubes. One of the reasons for leaving the stock tubes in place through break-in and further is to get to know the sound of your new piece of gear, so when you begging trying new tubes you have a baseline to compare them to. With that said, the Sophia's are great in Dans designs. Or breaking with the stock tubes so's not put those hours on the Sophia's . Either way is a plus. OR don't be afraid to swop at will! But some say these tubes need a hundred hours or so of burn-in themselves."

That's what I was told at Modwright. I have only 60 hours on the tubes, and I'm not happy with the sound.  I've been told 400 hours will open it up...I am a bit impatient...I have it on 24/7 to speed up the process. Maybe I'll give it more time with the stock tubes, and then put in the Sophia's...I am hoping that all this waiting will pay off...Thanks for all the input!

[PETE6737]

Hello All
Well curiosity got the best of me at 72 hours of burn in.  I changed out the stock tubes to the Sophia's and the Philips rectifier tube. Instantly, I was very happy with the improved sound with no burn in time. I think I have a taste of things to come. The clarity is night and day over the stock tubes. Now I'll at least enjoy the transformation of the burn in. Thank you for all the advice. Pete