Old tube out of my amp
 

I picked up cheap a Peavey T-Max amp last week and I love it overall! I have been busy, however still made time to try/test it out a couple times. Everything is good. Never owning any amp before that had tubes I posted a thread about the pre-amp 12AX7 that's in it and about replacing it if I should. I received a lot of great responses and a fellow Talk Bass member very kindly actually sent me a Mesa/Boogie 12AX7 to try out. I have been unusually busy since last weekend, but finally tonight I sat down and opened the amp.

The 12AX7 that was in it sound alright to me (again having no real tube knowledge) but I wanted to try out the Mesa tube so I open the amps case, wiggled the tube loose and then put the Mesa tube in. I plugged the amp back into the outlet and powered it on. I let it warm up about five minutes then started playing. I did notice the Mesa tube when using the tube channel did offer a little more gain and distortion which I like and also I swear it was even a little louder and clearer, however that could just be myself telling me that because I know this is just simply one 12AX7 tube and in the pre-amp at that. But I liked what I heard so I left it in there.

I am now curious about the old tube. Could it be the original that came in the amp from Peavey's factory? I included a photo below, it's a crappy cell photo but on it in goldish text it is marked "SVETLANA ELECTRON DEVICES 12AX7 MADE IN RUSSIA." The tube still works so I don't want to discard it, however it could be old too. I heard pre-amp tubes last long but if this is the original it's over 15 or more years old. Any insight on this tube? I have heard some praise for the true Russian made tubes, but not sure about this one.

Not a particularly valuable tube I'm afraid, but you know it is a good ( Working) tube, so keep it. If it was a Winged C, well, anyway you should keep it as a spare. Good to have on a gig.

As an aside, I have never believed a single 12AX7 in the preamp made much difference, but you could have some fun testing that theory out. There are a lot of great old 12AX7s out there. Get your hands on an old Mullard or Telefunken and see if it changes the way it sounds.

Svetlana has been making great tubes for decades and continues to produce them in St. Petersburg, Russia. I've used their 6L6 power tubes and they sound fantastic. One confusing thing though is that New Sensor bought the Svetlana name and some of their designs. Not sure where those tubes are produced now. The original company is now know as SED and continues to make great products. Here's a couple links to the company and a source to replace the original tube if you want.

http://www.sedtubes.com/

http://www.thetubestore.com/Svetlana-12AX7

Jeff

Bear in mind gain is how much louder something makes the signal, and breakup is a different thing. Often the two are confused, because more gain from a component can make the following one break up more due to not dealing with the hotter signal, but more distortion can mean a weaker valve rather than a stronger one, don't assume more breakup is more gain, it might just be coping less well.

Tubes don't really age. I have a 1967 blackface Bassman and the tubes in it are the same ones that were in it when I got it in '67. I have two tube testers and I've checked them - they're OK.

Tubes totally age. Some age better than others.

Perhaps true, but 15 years isn't much to a good tube.

That is the difference to tubes produced in the 60's where a high percentage never left the factory! Today's tubes don't have nearly the quality standards. But they all age with use.

Thanks for the responses. I was not expecting that I had a rare tube or anything just was curious to know more about the tube that was already in the amp. I honestly do think the Mesa tube does make the tube channel sound better, but I know one simple 12AX7 will not make a huge difference. It's only gainy because I turn the gain all the way up to 10 for my distortion and use the solid state channel as my clean channel.

Sadly the "older" Russian tube broke last night shortly after I started this thread in fact (coincidence?). I was in my garage putting my tools back and I set the tube on the bench and it rolled off and the glass broke on the bottom. At least I replaced it with the Mesa one first and at least I know the Mesa tube should now be good for a long long time (I hope).

Get you a spare and carry it with you to gigs.

For sure. Extra strings just in case, extra picks just in case and now extra tube just in case. (Hopefully soon I'll be able to add extra bass just in case).