[JKDJedi]

Yes, it looks like it will go on to a high price. What does this description mean, 48/44, and why does it speak in the plural for one tube "each tube"? It's not NOS, but are these readings "NOS-like" or much below?

"Western Electric 5998/421A Vacuum Tube Tested. Each tube exceeded the minimum value listed in the Department of the Army technical bulletin. Triode 1/Triode 2 tested values: 48/44. All tubes were tested on TV-7D/U."

It has dual triodes (which is normal for 6sn7, 6as7g, etc) meaning one triode will pull left and the other triode right channel duties. Versus that rare tube (like the 6J5) which only has one triode. You'd need two of those tubes, one for left and another for right. Speaking of that listing I posted..50 is considered a low number and anything above 70 is considered NOS. So this is a very weak tube. HOWEVER. That's just test numbers. imo you can still get some enjoyment off tubes tested this low. How bad you want a tube determines it's worth. Is a low tested tube worth the asking price? All subjective.

 

[CaptainFantastic]

Has anyone seen a Western Electric with this type of font on it? It seems to be from 1981. Someone posted in this thread a picture of a tube marked 81.. and it had the usual WE font we see on all tubes. What could this be about?

 

[CaptainFantastic]

When I run HifiShark.com on Western Electric 421A there are some Japanese auction listings open and even more closed. It's only in these that some of the tubes have this different yellow font. Any thoughts from the community if these are indeed true WE 421As?

 

[JKDJedi]

When I run HifiShark.com on Western Electric 421A there are some Japanese auction listings open and even more closed. It's only in these that some of the tubes have this different yellow font. Any thoughts from the community if these are indeed true WE 421As?

The one pictured there above seems to be the real deal, domino plates and thick getter wires. These tubes have slight variations from decade to decade. Me personally, wouldn't grab anything from a Japanese auction. Those guys are expert counterfeit artists. They'll sell you a foton and say it's a Brimar.

 

[CaptainFantastic]

The one pictured there above seems to be the real deal, domino plates and thick getter wires. These tubes have slight variations from decade to decade. Me personally, wouldn't grab anything from a Japanese auction. Those guys are expert counterfeit artists. They'll sell you a foton and say it's a Brimar.

Thanks!

No, this one is not from one of the Japanese auctions. It's from an audiophile in Italy, an older gentleman with a large collection of tubes who has started selling. He says it was brought to him some twenty years ago by Bé Yamamura, who was a friend. So there is the Japan connection that way, it came from Japan, but apparently from an unimpeachable source.

 

[JKDJedi]

Thanks!

No, this one is not from one of the Japanese auctions. It's from an audiophile in Italy, an older gentleman with a large collection of tubes who has started selling. He says it was brought to him some twenty years ago by Bé Yamamura, who was a friend. So there is the Japan connection that way, it came from Japan, but apparently from an unimpeachable source.

lol..How many of these are you grabbing..you have like 6 already! I was bidding on one couple weeks ago and lost out. Have to pace myself here, easy to get lost just buying and collecting.. (speaking about myself) time to enjoy some of these. Let us know how that works out please, would love to hear your impressions on the tube.

 

[CaptainFantastic]

lol..How many of these are you grabbing..you have like 6 already! I was bidding on one couple weeks ago and lost out. Have to pace myself here, easy to get lost just buying and collecting.. (speaking about myself) time to enjoy some of these. Let us know how that works out please, would love to hear your impressions on the tube.

Yes, it will be time to stop soon, very soon. I actually have only one WE 421A so far, but I do have a bunch of 5998s.

By the way, the 6520 that came yesterday went in for a trial run. It lights up brighter than the 5998s, that was my initial observation. It's perfectly quiet, really seems to be in pefect shape. I really, really, enjoyed the sound. Then when I was done with the tube amp, as I always do, I stopped the sound, lowered the volume on the amp, and unplugged the headphones. I plugged them in to the RME directly and continued the same track. I was surprised how much brighter the sound was. Normally going from tube amp with 5998s or 421A the change is a loss of soundstage and "life" to the sound. This time it also seemed brighter. Which leads me to a very preliminary conclusion that the 6520 has quite a warm sound, pushes the vocals back a bit and everything sounds smooth and relaxing. I have to do more testing. It wouldn't be a negative. I do want the best out of my tracks with vocals, but this seems to be a nice addition to the collection, one that provides a different sound.

 

[JKDJedi]

Yes, it will be time to stop soon, very soon. I actually have only one WE 421A so far, but I do have a bunch of 5998s.

By the way, the 6520 that came yesterday went in for a trial run. It lights up brighter than the 5998s, that was my initial observation. It's perfectly quiet, really seems to be in pefect shape. I really, really, enjoyed the sound. Then when I was done with the tube amp, as I always do, I stopped the sound, lowered the volume on the amp, and unplugged the headphones. I plugged them in to the RME directly and continued the same track. I was surprised how much brighter the sound was. Normally going from tube amp with 5998s or 421A the change is a loss of soundstage and "life" to the sound. This time it also seemed brighter. Which leads me to a very preliminary conclusion that the 6520 has quite a warm sound, pushes the vocals back a bit and everything sounds smooth and relaxing. I have to do more testing. It wouldn't be a negative. I do want the best out of my tracks with vocals, but this seems to be a nice addition to the collection, one that provides a different sound.

I really love the sound of the 6520. and yes, a little warmer than the 5998. My 6520 has the domino plates as I suspect yours has, I actually prefer the 6520 over the 5998. A highly musical tube.

 

[CaptainFantastic]

I really love the sound of the 6520. and yes, a little warmer than the 5998. My 6520 has the domino plates as I suspect yours has, I actually prefer the 6520 over the 5998. A highly musical tube.

Ah, good to hear your impressions of it. Yes, it does seem to be highly musical.

Yes, mine has the domino plates as well. As posted in the other thread:

 

[CaptainFantastic]

Oh, I just realized that you are the one who wanted this tube but then asked us to grab it before you. Thanks and SORRY at the same time...

 

[JKDJedi]

Oh, I just realized that you are the one who wanted this tube but then asked us to grab it before you. Thanks and SORRY at the same time...

You Grabbed it...L M F A O... Nice!! and thanks!! Soon as I saw the Motorola my head started working (IS that the tube I wanted?/) ...very nice.. small world.. I don't get all the updates to all the threads here from some weird reason..I'm probably following to many.. all good.... And please let us know how that 421a deal goes.

 

[CaptainFantastic]

And please let us know how that 421a deal goes.

It went well. I am the owner of an additional four 421A NOS tubes, a matched quartet. This is it, I am done buying 5998 and 421A tubes.

I will post visual evidence once they get here.

 

[JKDJedi]

Here are some interesting numbers from the data sheets... the ones listed here are where these tubes differ.




Plate Current Per Section - 421A 125 milliamperes 5998 140 milliamperes

Transconductance per Section - 421A 20000 Micromhos 5998 14000 Micromhos

Plate Voltage - 421A 250 volts 5998 275 volts

Plate Dissipation - 421A 13 watts 5998 15 watts

Heater-Cathode Voltage - 421A 150 volts 5998 100 volts (heater current same on both) 2.4 amps

Amplification Factor - 421A 5.9-6.1 5998 4.8-6.2

Transconductance - 421A 18000-20000 5998 11000-17000

"Also there's discussion that 421A have tighter tolerances. manufacturers were required to match the sections within a certain % whereas a regular 6AS7G may be allowed up to 20%. so for computer or military use, the higher tolerances are typically required before they can sell to the gov".

5998 - medium gain at 5, full-bodied sound, same current load as 6AS7

421A - same as 5998 but with matched plates/sections <--------- Tighter tolerances = BETER TUBE?

" if the 5998 is tested and the plates measure very closely, then they would perform just like a 421A. the 421A may be inherently superior out the gate, but remember that they are 50+ years old now..... how they were stored and how they were used prior would affect how they measure now". - anonymous

 

[Krutsch]

I really love the sound of the 6520. and yes, a little warmer than the 5998. My 6520 has the domino plates as I suspect yours has, I actually prefer the 6520 over the 5998. A highly musical tube.

I have three of these and, yes, they are great tubes.

 

[Wid]

Just read through the thread, very interesting. Anyone have an idea on the date of this 5998 ?