Question on tube types. Wing C SED EL34 to replace stock tubes

[chillytouch]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

No not normal Did you bias your amp when installing the new tubes ? Do you know what an amp bias is ? I kinda doubt it cuz until yesterday u dint even know what a =C= was/


Nothing should be "burning" in a tube amp.

Were your power tubes glowing like orange fireballs ?

I'll take a look at the back next time i use it. Basically when I first put the tubes back and booted it up, I was connected to the tube expander. I turned volume to about noon, played a bit and when I put my head close to the amp I smelled it a bit.
After that I disconnected it from the tube expander and plugged it right into the speaker cab. For this I kept the master vol super low, like 1-2. Played for 10 minutes, no smell.

I didn't bias it. I was told these amps run cold so there's not much risk in damaging it, BUT I am going to get it biased. I just can't right now because my local shop is closed... I'm hoping they can do it next month if not then June... I'll check for red-plating.

For what it's worth they sounded really awesome the few minutes I did try it. I definitely have to figure out the settings on the waza tube expander though, because it sounded way better straight through the cab. I bought the TE so i could push the power tubes.

[beaubrummels]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

If it’s biased cold, it would have sounded dark, rather than awesome. If it sounded bright and awesome it likely would have been running the tubes hot.

I’m not familiar with the BOSS Tube Expander, but if it’s anything like a Weber MASS, mine has an actual speaker driver inside as the variable load (without any cone to produce sound) and it smelled the first few hours of use in its life, then stopped)

[devastone]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

There is a lot of heat being generated from the tubes and what ever load box you are using, so, there is probably some smell for the first few uses. But yes, make sure the tubes are glowing just lightly orange, not red.

And, if you turned the volume up when you put the new tubes in, yes, of course they sound better than the other ones at low volumes. I hope they are everything you hoped for, especially at that price, I understand, sometimes we just have to try something for ourselves.

[JMP/HBE]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes









Before you burn down yer Moms house you may want to ask her if her home-owners insurance premiums are paid up.
You're going to want to have 911 on speed dial too.

I give you about a 3% survival rate.

[chillytouch]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

Before you burn down yer Moms house you may want to ask her if her home-owners insurance premiums are paid up.
You're going to want to have 911 on speed dial too.

I give you about a 3% survival rate.

Ha, Wish I still lived with her. Would get to see her during all this craziness if that were the case.

[devastone]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

An output tube can easily be 300 - 400 or more degrees C, just the dust from sitting on the shelf will smell "warm", I don't remember new tubes that didn't when I put them in, and yes, I know how to bias.

[JMP/HBE]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

An output tube can easily be 300 - 400 or more degrees C, just the dust from sitting on the shelf will smell "warm", I don't remember new tubes that didn't when I put them in, and yes, I know how to bias.

Maybe with no other contributing factors by itself but :

A] He swapped power tubes in a tube amp without biasing or checking plate voltage.

B] He is juicing the amp with an attenuator with said un-biased tubes.

C] Amp is emitting "burning smell".

Doesn't take a PhD to see where this is going.

All my amps including my 42 yr old Marshall have a really cool "tube amp smell" but not even the slightest bit "burning".

Not going to affect my day to day operations if this guy fries his Mexican amp.

[devastone]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

I was reading between the lines, he said a little smell and that he had to stick his head down to it to smell it, I think it was just the new tube warm up smell. He also said it went away.

[chillytouch]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

I was reading between the lines, he said a little smell and that he had to stick his head down to it to smell it, I think it was just the new tube warm up smell. He also said it went away.

Well so, it went away when I disconnected it from the attenuator and plugged it right into the cab. so basically, it smelled a little when the vol was on 6 with the attenuator vs on 1-2 plugged into the cab where it didn't smell.

I'm going to test this again tonight. I will check the back for red plating and see.

I called my local music shop to see if they'd let me drop it off for biasing since their showroom is closed but they're still operating, but they're not taking any new jobs. stinks.

Also, I gotta be honest maybe what I was smelling was just the "Tube amp smell". Can't remember tbh, it was for like 2 seconds. Also how does the amp being made in Mexico factor in lol.

[Lake Placid Blues]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

Sometimes tubes with beam forming plates are called beam pentodes, instead of beam tetrodes or in Europe kinkless tetrodes. This is because the beam forming plates perform the essentially same function that a suppressor grid performs.

Strictly speaking a tube should have a suppressor grid to be a pentode. The suppressor grid is the 5th element. I guess we could stretch the definition a bit to say that beam forming plates are a 5th element as well. But this also why there is so much confusion about what is a pentode and what is beam tetrode.

They don't sound exactly the same. Beam tetrodes have more open mids, and pentodes have more dense mids.

[beaubrummels]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

Sometimes tubes with beam forming plates are called beam pentodes, instead of beam tetrodes or in Europe kinkless tetrodes. This is because the beam forming plates perform the essentially same function that a suppressor grid performs.

Strictly speaking a tube should have a suppressor grid to be a pentode. The suppressor grid is the 5th element. I guess we could stretch the definition a bit to say that beam forming plates are a 5th element as well. But this also why there is so much confusion about what is a pentode and what is beam tetrode.

They don't sound exactly the same. Beam tetrodes have more open mids, and pentodes have more dense mids.

I was reading up on the history of the 6CA7 and I’m starting to think the term ‘beam pentode’ may have came about to disguise the fact that the early Tung-Sol and Sylvania/GE 6CA7 was actually a true pentode with a suppressor grid, but had a beam power anode plate (which wrapped around and hid all the internals), possibly trying to get around the Philips pentode patent (marketing, as JMP pointed out). The 6CA7 was designed to be a drop in replacement for the EL34, as a cheaper domestic alternative and avoid the cost of import at the time.

[JMP/HBE]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

Well so, it went away when I disconnected it from the attenuator and plugged it right into the cab. so basically, it smelled a little when the vol was on 6 with the attenuator vs on 1-2 plugged into the cab where it didn't smell.

I'm going to test this again tonight. I will check the back for red plating and see.

I called my local music shop to see if they'd let me drop it off for biasing since their showroom is closed but they're still operating, but they're not taking any new jobs. stinks.

Also, I gotta be honest maybe what I was smelling was just the "Tube amp smell". Can't remember tbh, it was for like 2 seconds. Also how does the amp being made in Mexico factor in lol.

Now you're minimizing and downplaying your first response. If it smelled like hamburgers im sure you would have said so.
Then pretending hamburgers really smelled like pizza doesn't make it so.

Nothing on earth smells like "burning" but "burning".

[chillytouch]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

So I played for an hour with the amp hooked up to the waza. Master volume a little below noon. No burning smell. I looked through the back and the gray metal plate was not glowing, you could definitely see the filaments glowing orangeish/red underneath.

These tubes definitely sound awesome though. I think part is the tubes, and part is I also get the el34 breakup sound by using the waza cause I can raise the volume a bit more than I usually can.

Thanks again all I appreciate the feedback/help. I'll definitely get it biased when I can, who knows maybe a tech can get it hotter and make it sound even better.

[JMP/HBE]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

If you really like your amp & want to keep it i would not play it til you get it biased.
But ive got 4 decades of tube amp experience & bias my own.

What do i know ?

[dave74]

Re: Question on tube types. Wing C SED EL34 to replace stock tubes

Bias is like the amp's blood pressure. If it runs wild it can easily have a quick and deadly heart attack!
It's even more critical (I've been told) in an amp with multiple pairs of power tubes, due to the balancing issue, which I think relates to the transformer.

I know basically nothing on this, but get it biased accurately before using it anymore. it's too great of amp to risk stressing it.