Not secondary, primary emission.
You need to crank up the Richardson-Dushman equation in a spreadsheet (don't try it on a calculator, the numbers are out of range). When you do, you will discover that the slight difference in work function between gold and tungsten makes a huge difference to emission. However, emission is also strongly dependent on temperature, so good grid heatsinking is just as effective, and was probably cheaper.
You need to crank up the Richardson-Dushman equation in a spreadsheet (don't try it on a calculator, the numbers are out of range). When you do, you will discover that the slight difference in work function between gold and tungsten makes a huge difference to emission. However, emission is also strongly dependent on temperature, so good grid heatsinking is just as effective, and was probably cheaper.
Hi,
Order some EL34s or whatever needs the same box and you'll notice the same magnoval writing on the outside of that carton...
Let's face it EI started out as a TV tube company.
Which reminds me of the David Manley KT90 story...
He didn't want a TV tube like the EL509/519...
Of course he didn't want to use magnoval sockets and anode caps, he wanted something more powerful than a KT88/6550 and that's were the EL509/519 comes in handy: rewire it for an octal socket and give it a designation just aboce the KT88 and hey, presto.
However when there was a shortage of 12AT7A in the Nineties they all of a sudden didn't have the clout to tell EI to do a production run?
One that made my company plenty of cash or did that never happen either?
It never happened because REL was stalling the whole thing supplying us with the oddest samples of what didn't even came close to a 12AT7A/ECC81.
That's the industry for you, folk.
Cheers,😉
Order some EL34s or whatever needs the same box and you'll notice the same magnoval writing on the outside of that carton...
Let's face it EI started out as a TV tube company.
Which reminds me of the David Manley KT90 story...
He didn't want a TV tube like the EL509/519...
Of course he didn't want to use magnoval sockets and anode caps, he wanted something more powerful than a KT88/6550 and that's were the EL509/519 comes in handy: rewire it for an octal socket and give it a designation just aboce the KT88 and hey, presto.
However when there was a shortage of 12AT7A in the Nineties they all of a sudden didn't have the clout to tell EI to do a production run?
One that made my company plenty of cash or did that never happen either?
It never happened because REL was stalling the whole thing supplying us with the oddest samples of what didn't even came close to a 12AT7A/ECC81.
That's the industry for you, folk.
Cheers,😉
Sorry, I did not note this earlier.Borc said:
I am living some 300km from Nis and I am not very deeply in the tube story but I guess a few simple notices might be useful and new for some. EI was an electronic industry giant (and is still supposed to be but as I heard doesn’t stand very well for certain time – embargo, transition, and general local recession/collapse during 90s had very bad effect on this company) employing, if I am not mistaken, more than 10000 workers, so you might easily understand the nature of the company. The factory had cooperation not only with Telefunken and Philips but also with, say, Honeywell (during 80s). They’ve been making also some audio equipment. For the whole company the tube manufacturing is the marginal part of their activity. I guess any their tube might be relatively easily found locally, but if one needs recommendation I should check more.
Pedja
I guess these people should know what they are selling (they are making some decent devices, a bulk of them are tube based and one of them uses KT90) and I guess they’ll not have a problem with English.
http://www.korato.com/index_e.htm
Click the “Audio Tubes” link, KT90 is listed.
Pedja
http://www.korato.com/index_e.htm
Click the “Audio Tubes” link, KT90 is listed.
Pedja
Yes EC8010....thanks for clearing this snippet up. Got carried away. However for the average to notice the differences, the tube has to be basically thrashed to overheat and reflective heat within the tube effecting other metastable conditions.. An unlikely scenario by most tube lovers except hard driven AB1 & 2 conditions with high B+.
I can see the point about grid heatsinking, (I overlooked this one) the laws of material physics prevail. Motto keep your tubes cool and run the heaters at the correct voltage.
Now I know what to look for electrically.
rich
I can see the point about grid heatsinking, (I overlooked this one) the laws of material physics prevail. Motto keep your tubes cool and run the heaters at the correct voltage.
Now I know what to look for electrically.
rich
I`ve ordered 10 off the new Electro Harmonix KT90,if they keep in fashion of the other EH tubes they should be considerably better than what EI had, which by user reports were better than any 6550 or kt88,if you got good ones.
I`ve been blessed or cursed to try these new Kt90`s,as their not available for retail yet, but i will report on my findings.
Also EveAnna Manley will post on the subject soon, as
soon
as she gets registered, and set straight any rumors that have been said about the EI KT90
Cheers George
I`ve been blessed or cursed to try these new Kt90`s,as their not available for retail yet, but i will report on my findings.
Also EveAnna Manley will post on the subject soon, as
soon
as she gets registered, and set straight any rumors that have been said about the EI KT90
Cheers George
Hi,
Not that it's all that important to me, I look forward to what she'll have to say.
For the record, she wasn't involved in any way when this happened, wasn't even part of the company at that particular point in time...
So, what can she tell other than what DM told her?
I don't doubt for a minute that DM wanted this KT90 to avoid the use of topcaps and magnoval sockets but saying that it's not using the EL519 tooling and materials is pushing my knowledge of the the industry to the max.
I did say I was 100% sure of what I claimed and I don't do that too lightly...
Now, I'm very curious of what EH is going to pull off....a USSR KT90 based on their version of the EL519?
Don't get your hopes up, they're doing that already albeit not under the EH brandname.
In the meantime I'm eagerly awaiting a sensible reply.
Just don't get me started on how, what and for what reason the industry works the way it works but just take my word for it that it's rarely ever working for the audio business...
Cheers,😉
Not that it's all that important to me, I look forward to what she'll have to say.
For the record, she wasn't involved in any way when this happened, wasn't even part of the company at that particular point in time...
So, what can she tell other than what DM told her?
I don't doubt for a minute that DM wanted this KT90 to avoid the use of topcaps and magnoval sockets but saying that it's not using the EL519 tooling and materials is pushing my knowledge of the the industry to the max.
I did say I was 100% sure of what I claimed and I don't do that too lightly...
Now, I'm very curious of what EH is going to pull off....a USSR KT90 based on their version of the EL519?
Don't get your hopes up, they're doing that already albeit not under the EH brandname.
In the meantime I'm eagerly awaiting a sensible reply.
Just don't get me started on how, what and for what reason the industry works the way it works but just take my word for it that it's rarely ever working for the audio business...
Cheers,😉
Hi Rich,
Sure, a reply with the datasheets went out on 20/12 at 16:46.
I can resend it in case it was lost.
Cheers,😉
Sure, a reply with the datasheets went out on 20/12 at 16:46.
I can resend it in case it was lost.
Cheers,😉
Links to Spec
http://www.triodeel.com/kt90-1.gif
http://www.triodeel.com/kt90-2.gif
316a
fdegrove said:
http://www.triodeel.com/kt90-1.gif
http://www.triodeel.com/kt90-2.gif
316a
Frank,
Manley Labs had nothing to do with the KT90. Manley Labs was started in 1993 by me and David when we split up from VTL.
I started working at VTL in late January 1989. In January 1990 David and I went to the Ei factory for the first time and met with those people and got the first 4 samples of this KT90. We went again in May 1990, and then David went by himself a third time a year later.
So don't spew out misinformation about me and make claims of being 100% right when you are 100% wrong. I was there. I stand by the posts I wrote on AA quoted on the previous page of this thread. No need to type all that out again.
I have a box full of the new russian KT90 version the Mike Matthews sent me but haven't had time to plug them in yet with end of year holidays and all. After CES and NAMM in January I hope to get them into some amps, onto the curve tracer and check 'em out.
I have also had samples of an octal based EL519 from russia but they are a very different tube from a KT90. Obviously. Read the data sheets. Check 'em out. I did. I am hoping the box of russian "KT90's" sitting on my desk are not those same russian octal based EL519's. Can't use 'em. I haven't even looked at the russian KT90's yet and I am outta here for two weeks vacation flying out at midnight tonight so, happy holidays and see ya later! Gotta get packing!
Manley Labs had nothing to do with the KT90. Manley Labs was started in 1993 by me and David when we split up from VTL.
I started working at VTL in late January 1989. In January 1990 David and I went to the Ei factory for the first time and met with those people and got the first 4 samples of this KT90. We went again in May 1990, and then David went by himself a third time a year later.
So don't spew out misinformation about me and make claims of being 100% right when you are 100% wrong. I was there. I stand by the posts I wrote on AA quoted on the previous page of this thread. No need to type all that out again.
I have a box full of the new russian KT90 version the Mike Matthews sent me but haven't had time to plug them in yet with end of year holidays and all. After CES and NAMM in January I hope to get them into some amps, onto the curve tracer and check 'em out.
I have also had samples of an octal based EL519 from russia but they are a very different tube from a KT90. Obviously. Read the data sheets. Check 'em out. I did. I am hoping the box of russian "KT90's" sitting on my desk are not those same russian octal based EL519's. Can't use 'em. I haven't even looked at the russian KT90's yet and I am outta here for two weeks vacation flying out at midnight tonight so, happy holidays and see ya later! Gotta get packing!
Cara Eva,
Don't think I said it had...
Yes, I also know why.
Yes, I'm not saying you weren't or was I?
Right or wrong about what exactly? I know David was involved in the development of the KT90, I know I met David several times and talked to him, I know I serviced alot of VTL gear, I know that the KT90 is a EL519 resocketed.
And that's my point...The rest is bla bla....
Yes, I know Mike too and the Russian KT90s will tell you that it's a EL519 resocketed once again, improved on earlier versions or not.
Yes, tube parameters will differ based on how the resocketing is done but it still is based around the EL519 and the tooling used is still the same as used for the EL519. That was my point in the first place.
Buon viaggio,😉
Don't think I said it had...
Yes, I also know why.
Yes, I'm not saying you weren't or was I?
Right or wrong about what exactly? I know David was involved in the development of the KT90, I know I met David several times and talked to him, I know I serviced alot of VTL gear, I know that the KT90 is a EL519 resocketed.
And that's my point...The rest is bla bla....
Yes, I know Mike too and the Russian KT90s will tell you that it's a EL519 resocketed once again, improved on earlier versions or not.
Yes, tube parameters will differ based on how the resocketing is done but it still is based around the EL519 and the tooling used is still the same as used for the EL519. That was my point in the first place.
Buon viaggio,😉
EL509 / KT90
Hi Frank ,
Before you dig your heels in I can vouch that the KT90 is a different beast . The datasheet links I posted indicate about -40V of bias at about the same operating point I'm using PL509 trioded at . The PL509 sits at about -75V bias , curves traced on a number of different samples of PL509 indicate mu is about 4 against mu of 9 for trioded KT90
316a
fdegrove said:
Hi Frank ,
Before you dig your heels in I can vouch that the KT90 is a different beast . The datasheet links I posted indicate about -40V of bias at about the same operating point I'm using PL509 trioded at . The PL509 sits at about -75V bias , curves traced on a number of different samples of PL509 indicate mu is about 4 against mu of 9 for trioded KT90
316a
Frank, you had typed this:
And this is what I was referring to as 100% wrong. What do you you want to see my pay stubs and airplane tickets? Pictures? I was married to the guy and you know him because you have talked to him a few times and you fixed some amps? oh nevermind...
If you want to believe that a KT90 is an EL519 that's just been resocketed, that's your right... I guess... whatever dude. The tooling is the same for lots of tube types but it doesn't make a 6072 a 12AX7. Or a KT90 an EL519.
And this is what I was referring to as 100% wrong. What do you you want to see my pay stubs and airplane tickets? Pictures? I was married to the guy and you know him because you have talked to him a few times and you fixed some amps? oh nevermind...
If you want to believe that a KT90 is an EL519 that's just been resocketed, that's your right... I guess... whatever dude. The tooling is the same for lots of tube types but it doesn't make a 6072 a 12AX7. Or a KT90 an EL519.
Frank, i started this thread as information about a new KT90 about to be released onto the market by a well respected manufacturer, but this has stired the demon up in you , and you`ve had nothing but negative remarks to say about KT90`s and or the relationship with the Manley corp.
Frank did somone do something EVIL to you with a KT90 for you to behave this way.
Love George (and i hope that the EH KT90 becomes a CLASSIC)
Frank did somone do something EVIL to you with a KT90 for you to behave this way.
Love George (and i hope that the EH KT90 becomes a CLASSIC)
Hi,
A manufacturer? EH is not a manufacture of tubes, neither is VTL for that matter.
Get your facts straight please .
Iv'e got nothing against either VTL or Manley Labs, fairy tails are just that though...
Cheers,😉
A manufacturer? EH is not a manufacture of tubes, neither is VTL for that matter.
Get your facts straight please .
Iv'e got nothing against either VTL or Manley Labs, fairy tails are just that though...
Cheers,😉
Whoa, we definately a KT90 Tube Extractor for Frank, does anyone know where to get one, please post onto Frank, i`m sure he`ll appreicate it, it must be soooooo painful.
Cheers George
Cheers George
KT90
Appropo the KT90.........an uprated KT88 But I have my doubts....... However, as a user of 88’s I have some questions regarding the KT90. Perhaps others can reply....I’m not convinced yet, that the way I run tubes that the KT90 is a better bet. If it was a runner then why has it taken so long that other vendors haven’t gotten in on the act ?
1. The bogey recommendations for running the KT88 in an o/p stage are that the anodes be orientated 90° from each other and tubes be 4” apart on the horiz. The GEC spec stipulates that the envelope temperature not exceed 250°C (sim for 6550) . That’s pretty hard and fast.
2. The KT88 bulb/envelope dia is much larger. Why isn’t it similiar for the KT90 ? The reason I ask is that once I lost a pair of EL34 straights’ doing studio work .They overheated and the glass gradually collapsed inwards.
The reason I mention this, if one runs the tube as one will, you cannot avoid the risk of medium term overheating and the danger that neg bias cannot control anode current, leading to thermal runaway. I’m suprised that the KT90 envelope is smaller than the 6550.......Mullard produced a wide envelope EL34 for a reason. Let’s hear some others on this one.
3. Until someone comes up with a tangible KT90 and has punished and tested it with time, I shall stay with KT88’s. I might have to wait a long time.
rich
Appropo the KT90.........an uprated KT88 But I have my doubts....... However, as a user of 88’s I have some questions regarding the KT90. Perhaps others can reply....I’m not convinced yet, that the way I run tubes that the KT90 is a better bet. If it was a runner then why has it taken so long that other vendors haven’t gotten in on the act ?
1. The bogey recommendations for running the KT88 in an o/p stage are that the anodes be orientated 90° from each other and tubes be 4” apart on the horiz. The GEC spec stipulates that the envelope temperature not exceed 250°C (sim for 6550) . That’s pretty hard and fast.
2. The KT88 bulb/envelope dia is much larger. Why isn’t it similiar for the KT90 ? The reason I ask is that once I lost a pair of EL34 straights’ doing studio work .They overheated and the glass gradually collapsed inwards.
The reason I mention this, if one runs the tube as one will, you cannot avoid the risk of medium term overheating and the danger that neg bias cannot control anode current, leading to thermal runaway. I’m suprised that the KT90 envelope is smaller than the 6550.......Mullard produced a wide envelope EL34 for a reason. Let’s hear some others on this one.
3. Until someone comes up with a tangible KT90 and has punished and tested it with time, I shall stay with KT88’s. I might have to wait a long time.
rich
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