Musician Gear & Tech Discussion

While I was laid up, I decided to repair a chassis I had lying around and I got involved with some tubes. I was having heat issues and thought I was going to have to break out the testing equipment to read the MF values. (I was wrong.)

I started with some Sovtek 5881 tubes.

(Wow are these shitty, maybe others are decent but not these. They sound about as sterile as you can get. I know FENDER likes to use them in their amps stock, the question is why. If you have an amp using these, change them or you now know why your amp sounds like mud.)

From there I got the chance to use some RCA Victoria Metal Base 6L6's.
I understand that the metal base is due to the fact that they were for military applications.

(Wow, these sounded good. Not the loudest tubes in the world, but full of old time character. If you can find some of these that test out on your tube tester as new, try them...I liked them a lot. I just couldn't get a full compliment of them working in my amp.)

I got to see a regular fender replacement 5AR4 rectifier tube (RUBY).
(Chinese made junk and sounded like ass. It made my chassis act oddly and I removed it very quickly in favor of another 5U4. Some Chinese tubes are ok, but this wasn't one of them. AVOID AT ALL COSTS>. They are supposed to be a GZ34/5U4 replacement, just throw them in the garbage.)

I was sorting/testing and I came up with a RCA Victoria 5U4, a very nice tube. Again, testing is crucial. I found 3 and 1 tested off the chart. That's the one I used and it really made a noticeable difference.

In the end the real standout were JJ's Tubes, a newer version 6L6 that was loud, clean and really did exactly what you want them to do in a fender amp. The new JJ's (6L6) blew the doors off of all comers, even RCA/Svetlana vintage good testing tubes. (WHAAAATTT??@!?!?!?)

If you have an older amp that's acting up and you are considering a tube set change, try the JJ's. Now that I have heard the difference (I also got shocked 2x and burned so bad that I had solder in my thumb), the JJ's are the obvious choice.

Your ears will thank you..

I haven't played around with tubes a lot in my Super Reverb, but the best sounding tube I ever tried in my champ was a GE 6L6 I grabbed in a resale shop for a buck.

Be careful working with tube amps, They carry lethal voltage. The capacitors, mostly filter caps, should be drained before touching anything. You're actually lucky to be alive. Those things are literally deadly.

In the old days, we just went to Radio Shack or Lafayette Electronics and got whatever brand they had. Of course they were ALL good back then, no Asian crap.

Capt I lik JJs also, I put JJ 6V6s in my triple, in place of the 6L6s I had been running.

I went thru Euro Tubes and completely retubed my Triple I have a bunch of NOS tubes, that are supposed to be tube magic, but I wound up going back to the JJ setup, its warmer to my ears, I also replaced my rectifier tubes with some they sent, I think they are GZ34s.

I went thru a phase of buying all sorts of tubes, for my amps, Ive got some boxes full, but the JJs are doing it for me right now, but who knows that could change tomorrow!

I haven't played around with tubes a lot in my Super Reverb, but the best sounding tube I ever tried in my champ was a GE 6L6 I grabbed in a resale shop for a buck.

Be careful working with tube amps, They carry lethal voltage. The capacitors, mostly filter caps, should be drained before touching anything. You're actually lucky to be alive. Those things are literally deadly.

Pete, I have changed the tubes many times in my crate V32 never had a problem getting shocked. Is it dangerous to change tubes without draining the caps? Please advise! thanks in advance.

Make sure you at least unplug the chassis before you handle the tubes etc..

I got blasted because I was lazy and did not unplug chassis.
It'll wake you up..lol

No, changing tubes is usually not a problem, just let them cool first. They get hot enough to blister your fingers. Trust me on that one...

It's when you open it up and poke around inside that it gets dangerous. As long as you don't get inside the chassis, no problem. You can actually change tubes with it still plugged in without problems. All the dangerous stuff is inside. The filter capacitors (the biggest ones) hold a charge for a long time after it is unplugged, and it's literally lethal voltage. In most cases it can still kill you a week after being unplugged...or more, I think at least a month.

Ive always kept an oven mit in my gig bag in case I had to change out tubes, ussually its only been the V1, V2 or V2 tubes, or preamp tubes if you dont know the slots, Ive only once had to replace my power tubes at a gig.

I just carry a back up amp . . .

I can change tubes when I get home.

But frankly, it's never been an issue.

Of course I've not been at this as long as y'all.

George I carry a backup as well, but I also have fuses and a complete set of tubes for my big amp.

Fortunately I havent had any problems in the past 4-5 years!

But I have a plan A, B and C, just in case.

George I carry a backup as well, but I also have fuses and a complete set of tubes for my big amp.

Fortunately I havent had any problems in the past 4-5 years!

But I have a plan A, B and C, just in case.

Fuses ? Dang . . . I knew I was forgetting something

LOL..

I hadn't read this thread in a while and had to laugh on that one...I learned that lesson the hard way long ago. 3rd set, everything going well, suddenly I have no amp...Not a tube problem, I was playing a solid state at the time. Not a power problem, wall wart to my one distortion pedal was still good, same outlet. Talk about getting lucky, we had two of these amps (Peavey Pacer) and I was still waffling over which one sounded better and would switch back and forth trying to decide on one. Next day I found that infernal fuse...a box of fuses went in my gear bag later that day. About a dollar at that time...should have thought of it long before.

Just picked this up for a PA conversion project.

'47 Masco MA25P PA



You want to talk about vintage glass?



Shouldered Sylvania 6L6 power tubes and loctal 7B4 & 7N7 preamp tubes that predate 12AX7s! Harp players LOVE these amps. This is going to be a fun one.

Scored a few more tubes the other day.



I got them from an industrial customer of mine that bought them in '94. They asked me if I wanted to buy out some old inventory they were no longer using.

I replied "Um....yeah, I'll take care of those tubes for ya".

A sample testing of two came back with readings more like high gain 12AX7 than 5751......110/110 & 105/110 on a VTV tester.



Triple mica, foil getter.



**** Update ****

It turns out they are 12AX7 tubes after all. I doubt Shunguang labeled them that way, it was probably the reseller.

Enough of the CP's.....back to vintage glass.
Today's score from a old radio guy.

'48 GE 6072 Supposed to be awesome in V1 of a Tweed.





Sylvania 12AZ7A



Unknown 12AX7A RCA?



Tung-Sol 12AX7A