NOS tubes

[anewdefguitarist]

If you rush to do anything, you’re going to regret it in yhe long run. A bunch of morons are freaking out like the world is going to end but it isn’t. All this bull**** is going to pass. Chill.

??
I’m not panic buying. Im not hoarding tubes. I m not freaking out. My main amp has been out of commission since December, and had been in bad shape and getting worse since September…

so don’t tell me to chill.

im only asking for help/guidance on buying a brand of tube that isn’t Mesa branded, bc I didn’t feel comfortable buying without knowing what could happen if they weren’t within regulated specs for my amp.

 

[anewdefguitarist]

I always had a full set of spares in case I needed them, it makes life easier when there are disruptions. That said, time to unload all my old tubes....

I know a guy looking for 6L6’s lol

 

[beaubrummels]

Why not just buy Mesa then? FWIW, as HBE stated, Svets are not NOS tubes, some of the Mesas may come from the same factory. Or, e-mail Mesa support, they used to be good at answering questions. They do buy from all the manufacturers and test the tubes so they match up with their fixed bias so it is the safest bet.

Mesa has plenty of choices too - https://www.mesaboogie.com/tubes/power-tubes/index.html

Not sure if this is still 100% accurate, but - https://srl.utu.fi/~tke/MesaBoogie/Tube/mesa-tubes.html

What's interesting is what Mesa is labelling all 6L6s look like various different tube types.
The 441 looks like a 5881 (or current Tung-Sol 6L6GC STR, spec-wise identical to Svetlana version)
The 443 looks like a proper Svetlana-type 6L6
The 445 looks like an EHX 6CA7
The 5881 is the Sovtek coin base 5881/6L6

Without photos, hard to know what 420, 427, 430 and 454 were.

 

[anewdefguitarist]

What's interesting is what Mesa is labelling all 6L6s look like various different tube types.
The 441 looks like a 5881 (or current Tung-Sol 6L6GC STR, spec-wise identical to Svetlana version)
The 443 looks like a proper Svetlana-type 6L6
The 445 looks like an EHX 6CA7
The 5881 is the Sovtek coin base 5881/6L6

Without photos, hard to know what 420, 427, 430 and 454 were.

Yes! I thought the same thing lol makes it wonder about the 6CA7s

 

[JMP/HBE]

So anytime someone tries non-GT or Mesa tubes, they’re basically just rolling the dice?

That's the same for any tube on the planet Bro.
Any vacuum tube is a dice game.

 

[jeremy]

pffft. every set of gec kt66 tubes ive owned has been kick ass

 

[chadd]

What's interesting is what Mesa is labelling all 6L6s look like various different tube types.
The 441 looks like a 5881 (or current Tung-Sol 6L6GC STR, spec-wise identical to Svetlana version)
The 443 looks like a proper Svetlana-type 6L6
The 445 looks like an EHX 6CA7
The 5881 is the Sovtek coin base 5881/6L6

Without photos, hard to know what 420, 427, 430 and 454 were.

I'll get you a couple pics of 420s. I picked up some old stock a couple years ago

 

[dave74]

420 are 90s era shugaung
430 are 90s sovtec
440 are newer shugaung
445 are jj
447 are eh el34

^that's my mesa power collection

 

[dave74]

If anyone is willing to pay $70 a matched pair, there are 420 NOS in-stock

Let me know I'll PM you the link.

 

[chadd]

If anyone is willing to pay $70 a matched pair, there are 420 NOS in-stock

Let me know I'll PM you the link.

Damn, I have two matched pair in boxes.

 

[dave74]

Damn, I have two matched pair in boxes.

Before all this madness I snagged a couple matched quads at just over $75 per/quad. That's like $19 each lol.
He still has a few pair and a couple quads as of last night. Double the price now at $70 a pair.

 

[LLL]

pffft. every set of gec kt66 tubes ive owned has been kick ass

Ditto.

 

[Ewizard]

To answer your question more directly:

1. Even if you go with Mesa Branded tubes that are in their spec'd range, you should still bias the amplifier. There is a knob to do that inside the amp.

2. The metric at which Mesa comes to its rating will be different than what GT or any other company has. This is what makes it so that you buy their tubes as opposed to others. If you were to know what the ratings of the tubes were when new, you could in theory buy other tubes with similar spec's. You should still bias the amp though regardless.

3. GT and Mesa tubes are very likely coming from the same factory anyway. You pay a little more for them because they take some time to measure and mark the tubes to make it easier to buy another similarly spec'd tube from them.

4. Since I ALWAYS suggest biasing after any power tube swap, which grade or spec of the tube you get is irrelevant. Get a set that you think will get you where you want to be, rebias, and asses. If you don't like the sound of that spec of that tube, go the other way with it, buy a different spec ( colder or hotter ), rebias, and asses.

 

[NegativeEase]

To answer your question more directly:

1. Even if you go with Mesa Branded tubes that are in their spec'd range, you should still bias the amplifier. There is a knob to do that inside the amp.

2. The metric at which Mesa comes to its rating will be different than what GT or any other company has. This is what makes it so that you buy their tubes as opposed to others. If you were to know what the ratings of the tubes were when new, you could in theory buy other tubes with similar spec's. You should still bias the amp though regardless.

3. GT and Mesa tubes are very likely coming from the same factory anyway. You pay a little more for them because they take some time to measure and mark the tubes to make it easier to buy another similarly spec'd tube from them.

4. Since I ALWAYS suggest biasing after any power tube swap, which grade or spec of the tube you get is irrelevant. Get a set that you think will get you where you want to be, rebias, and asses. If you don't like the sound of that spec of that tube, go the other way with it, buy a different spec ( colder or hotter ), rebias, and asses.

Additionally, during post factory grading, that secondary stress test to protect against infant mortality in new amps is a lot of what companies like Mesa are trying to insulate themselves from.

 

[dave74]

To answer your question more directly:

1. Even if you go with Mesa Branded tubes that are in their spec'd range, you should still bias the amplifier. There is a knob to do that inside the amp.

2. The metric at which Mesa comes to its rating will be different than what GT or any other company has. This is what makes it so that you buy their tubes as opposed to others. If you were to know what the ratings of the tubes were when new, you could in theory buy other tubes with similar spec's. You should still bias the amp though regardless.

3. GT and Mesa tubes are very likely coming from the same factory anyway. You pay a little more for them because they take some time to measure and mark the tubes to make it easier to buy another similarly spec'd tube from them.

4. Since I ALWAYS suggest biasing after any power tube swap, which grade or spec of the tube you get is irrelevant. Get a set that you think will get you where you want to be, rebias, and asses. If you don't like the sound of that spec of that tube, go the other way with it, buy a different spec ( colder or hotter ), rebias, and asses.

But he is buying them for a fixed-bias single rectifier, so no need for any of that if using Mesa-branded.

 

[Ewizard]

But he is buying them for a fixed-bias single rectifier, so no need for any of that if using Mesa-branded.

However, there is no guarantee that their " ranged " tubes will be an exact match with ZERO need for biasing. If they do have a warranty for that I would be surprised. Each and every set of tubes should be biased for the best operating performance. While the differences between 50% biased and 60% biased may be of little worry, that little bit makes the difference between right and wrong. Right wand wrong is subjective in this case, but if the end USER wants colder, longer lasting, or hotter and less reliable, then that is only something that can be done by biasing ALL sets of tubes.

 

[dave74]

However, there is no guarantee that their " ranged " tubes will be an exact match with ZERO need for biasing. If they do have a warranty for that I would be surprised. Each and every set of tubes should be biased for the best operating performance. While the differences between 50% biased and 60% biased may be of little worry, that little bit makes the difference between right and wrong. Right wand wrong is subjective in this case, but if the end USER wants colder, longer lasting, or hotter and less reliable, then that is only something that can be done by biasing ALL sets of tubes.

Wouldn't you have to mod the single rectifier to make it's biasing adjustable?

 

[formula73]

??
I’m not panic buying. Im not hoarding tubes. I m not freaking out. My main amp has been out of commission since December, and had been in bad shape and getting worse since September…

so don’t tell me to chill.

im only asking for help/guidance on buying a brand of tube that isn’t Mesa branded, bc I didn’t feel comfortable buying without knowing what could happen if they weren’t within regulated specs for my amp.

Chill.

 

[Ewizard]

The Mesa " " rectifier series does not come with a knob per se to adjust the bias. There is a resistor that would require changing out to a proper value to achieve the desired bias.

The point I am making is that the stock value bias resistor is set to X value with the tubes sold with the amp to create their idea of proper bias. Ideally, you just need to buy Mesa's tubes with the same rating to continue having proper operation with no adjustment or tampering needed. However, there is no resistor value that will be perfect for any given set of tubes. It will be in the ballpark, but never perfect ( unless by chance it is exactly what the tubes need in order to meet your biasing desire ). So if the bias resistor falls on the high or low side of the " ideal " bias, and the range that the tubes are is large enough, it is possible that you can run a set of tubes either too hot or too cold.

This 100% negates personal opinion and desired bias operation. Some people want to cook the tubes, some want them biased as cold as Pluto is. The only way to achieve that is to bias each and every set to meet your desired goal.

 

[Ascension]

There are several tube companies who will sell you in spec tubes for fixed bias Boogie amps if you ask for them. know Doug with Dougs tubes would as would Eurotubes and also TAD if you requested it at one point.