Tube selection

[heaven]

I want to change the tube of my multieffect RP7 since it have been used for so many years. One sellers located in my country recommanded the below from his stock.

1. Russian made Sovtek 12AX7WXT premium
2. Yugoslavia made EI 12AX7
3. Ruby China made 12AX7

Just search in the web and can only find a little on what he recommanded.
So disappointed he dont have jj tube for sell and I think I will buy one from his three recommandation


Any idea? Thanks.

 

[Light]

Preamp tubes (with a few exceptions, none of which would be an issue here) don't wear out unless they have been abused. Power amp tubes wear out, but that is not what you have. Add to this the extremly low quality of ALL 12ax7 tubes which are being made right now (and I do mean EXTREMLY low). All things considered, unless you are having a specific problem which you have traced down to the tube, I would either leave it be, or buy a new one to have as a backup. If it works, I would not change it.


Light

"Cowards can never be moral."
M.K. Gandhi

 

[Light]

Oh, and I would recomend that if you DO get a new one, buy a couple of JJ's and pick the one which actually works (which is probably the best you can do with current production tubes).


Light

"Cowards can never be moral."
M.K. Gandhi

 

[heaven]

The reason I want to change the tube, is more just a experimental process and what to know how my effect will be sound after tube change, and I notice that the effect seems not that powerful when compare with the day I buy it.

I know that its might be dont have much sound difference after tube change with this old school effect, but 15-20 us dollors is not a big deal here.

Regarding to the seller recommandation quality, is it really that bad? Actually, I have no idea at all. I know JJ'S tube is good, but difficult to find one in my area. The stock tube of my effect is using 7025, 12ax7WA sovtek.

Thanks in advance.

 

[Light]

It is not that THOSE 12ax7's are bad. It is that ALL 12ax7's being made right now are that bad. There isn't a company out there who is making a really good 12ax7.

My guess, by the way, is that you won't notice any difference at all. At least, if the tube works you won't.


Light

"Cowards can never be moral."
M.K. Gandhi

 

[Clive Hugh]

There was a thread recently that was about the Electro Harmonix factory in Russia being threatened by the Russian Mafia so they might be hard to get, I recently replaced all my tubes with EH and am happy as a pig in shit but if you go to www.tubesandmore.com you can buy NOS which is stuff made back in the 60's for the military and never used, hence "new old stock"

 

[hungovermorning]

I know that its might be dont have much sound difference after tube change with this old school effect, but 15-20 us dollors is not a big deal here.

I bought an old Mullard and I like it very much. Since you don't need a pair or anything, a good testing Mullard should be pretty easy to fid in that price range and Mullards are legendary preamp tubes.
http://cgi.ebay.com/1-used-Mullard-...2QQihZ008QQcategoryZ73377QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/Mullard-ECC83-1...9QQihZ008QQcategoryZ64629QQrdZ1QQcmdZViewItem
Here's an EH that was referred to before for $12.75 to your door http://cgi.ebay.com/Electro-Harmoni...yZ121164QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

cheers,
scott