ECC82 choice for G9 preamp

[maxime]

hello
I have bought a ecc 82 lot (30 nos tubes from before 1965, mainly mazda). Being very happy about this discover (I did not know what tubes was in the batch when I bought it) I 'm thinking using those in a G9 preamp.
I was wondering about a good way to choose the best ones in the batch without a tube tester. listening for noise figures and measuring the frequency response at the output of the tubes itself was what I was thinking of.
here's my other question: is it ok swapping those preamp tubes with the power on?
best wishes to you
Maxime

 

[louder]

alo maxime
choose the ones with the least noise,and better sound.
best regards
pedro

 

[maxime]

hello
and thank you for your reply.
do you think I can hot-swap such preamp tubes while testing?
bye
max

 

[peter purpose]

[quote author="maxime"]do you think I can hot-swap such preamp tubes while testing?[/quote]

I wouldn't

 

[mojotron]

[quote author="peter purpose"][quote author="maxime"]do you think I can hot-swap such preamp tubes while testing?[/quote]

I wouldn't[/quote]

Ya I wouldn't either. The ECC 82 tubes from back then were Mullards I think... I have a few.

I just test them in a tube guitar pedal that I have, the strong ones are generally good ones, strongest ~= best... But, I'm not a purest.

 

[analag]

Hot swapping can cause what is known as cathode stripping...this is caused by having the fully B+ voltage hitting the plate while the cathode is still cold and not in the proper state of conduction. That is why tubes last much longer with a slow turn on PSU.

 

[CJ]

Plug em in hot. No biggy. Especially since you now own a ton. So your tube life goes from 5000 hours to 4500. Each. That's still an awful long time.
Learned to hot swap while in the TV Service Call biz, where you want to get in and out in a hurry. $24.50 labor per call plus parts in 1971. Needed four calls an afternoon to keep the boss happy. Don't even ask me about the housewifes. Don't join the Navy, that's all I can say.

I would not hot swap pwr tubes.

 

[Mailliw]

[quote author="CJ"]Plug em in hot. No biggy. Especially since you now own a ton. So your tube life goes from 5000 hours to 4500. Each. That's still an awful long time.
Learned to hot swap while in the TV Service Call biz, where you want to get in and out in a hurry. $24.50 labor per call plus parts in 1971. Needed four calls an afternoon to keep the boss happy. Don't even ask me about the housewifes. Don't join the Navy, that's all I can say.

I would not hot swap pwr tubes.[/quote]

I suppose sometimes it only took 1 call to make you happy then?

Would 4 of these be a good choice for the g9?:
http://store.triodestore.com/12auecelrust.html

 

[analag]

http://www.tubesandmore.com/
What about the 5963, huh
http://frank.yueksel.org/sheets/137/5/5963.pdf

 

[CJ]

Skip the radioactive stuff.
This guy actually plugs the tube in and listens before he sells:
But leave some for me!



http://kcanostubes.com/content/estore.asp

 

[analag]

Yeah at that price range, he should do more than just plug them in and listen...he should shine them up with Windex too.

 

[Mailliw]

[quote author="analag"]Yeah at that price range, he should do more than just plug them in and listen...he should shine them up with Windex too.[/quote]

Agreed, he should also wrap each pin in tissue paper and put a little woolen hat on it for shipping.

 

[CJ]

If you want the best possible sound out of your projects, as many of us here do, then you certainly do not want to skimp when it comes to purchasing vacuum tubes, as they are probably the single most influentilal component you can choose as far as sound is concerned. If you want to gamble on evilbay or go back and forth with retail outlets, returning stuff and buying stuff twice, paying for shipping along the way, knock yourself out. If you want to get it right the first time and move on to racking your project so you can start on the next one....

In other words, spending a litle more can sometimes end up saving you time and money. And hassles on the phone, and trips to the Post Office.

 

[analag]

You could be right, but I have a mighty big box of tubes...been collecting for years before the tube fad got out of hand....been building with tubes for a little over 29 years now and before I was a teenager too. I grew up with tubes on my mind. Believe it or not.

 

[Mailliw]

Anyone know which kind the retail gyraf preamp uses?

 

[analag]

Does it matter? I always try to add a little bit of my flavor to whatever I build...that makes it unique.

 

[Mailliw]

Just curious is all.

 

[maxime]

hello boys
and thanks for your reply. I have to confess: this lot of masda tubes appears to be an happy mistake. I bought the whole lot (30 tubes) for 50 euros without knowing about the quality of those... the seller is still selling huge quantities of nos french military tubes, if you're interested his name is Alain Daden and his email adress is [email protected], and a nice guy too.
so let's hotswap !
maxime

 

[CJ]

Mistake? Why?

Does he have any Viseux tubes?

 

[maxime]

I got in contact with the guy today and it seems that tubes stock is already finished... info go quick.
best wishes
M