not sure if this belongs in the 'Parts' category, my apologies if this is in the wrong place.
i've gotten the attention of someone at Electro-Harmonix/New Sensor in regards to the many confusing, incomplete or absent data points on their KT120, 150 and 170 datasheets. this person is very motivated to rectify this lack of usable information, and make these tubes more accessible to designers.
this is an official open call to the public, for any and all requests for additions and revisions to said datasheets. these requests will be delivered directly to the New Sensor design and testing technicians on April 22nd, so please post before then.
please be exhasutive and state all your requests, even if they have already been mentioned. please also feel free to indicate which requests you would like to be prioritized the most. i will be compiling a final list to send to them, and will be sure to accentuate items that got the most requests and placed the most highly on folx's lists.
please understand this is not a guarantee that any of these requests will procure published data, nor is it a guarantee of the timeline in which this might occur.
please also understand this is not a thread on which to discuss or compare the various merits of these tube models or the companies that make them. there are many other threads for such discussions - this is a thread to collect requests for datasheet revisions and additions, only.
one last note, and single exception to the above paragraph - since EHX/NS seems to be at least somewhat willing to innovate and create new tube models, i am personally taking this opportunity to provide some requests for what sort of tubes they prioritize the development of in the future. i have been told that these ideas are welcome and will be sent to the technicians as well. so by all means, please share your desires for what sorts of new tube models you'd like to see!
personally, i want to see subminiature pencil tubes, especially the frame grid types, see more focus. they were a brilliant idea too soon overshadowed by the rise of the transistor. just think of how awesome a new line of 6111/6112 style tubes would be! less space needed, more flexibility as to placement, less vulnerability to physical damage, high shock tolerance, lower operating voltages...
i've gotten the attention of someone at Electro-Harmonix/New Sensor in regards to the many confusing, incomplete or absent data points on their KT120, 150 and 170 datasheets. this person is very motivated to rectify this lack of usable information, and make these tubes more accessible to designers.
this is an official open call to the public, for any and all requests for additions and revisions to said datasheets. these requests will be delivered directly to the New Sensor design and testing technicians on April 22nd, so please post before then.
please be exhasutive and state all your requests, even if they have already been mentioned. please also feel free to indicate which requests you would like to be prioritized the most. i will be compiling a final list to send to them, and will be sure to accentuate items that got the most requests and placed the most highly on folx's lists.
please understand this is not a guarantee that any of these requests will procure published data, nor is it a guarantee of the timeline in which this might occur.
please also understand this is not a thread on which to discuss or compare the various merits of these tube models or the companies that make them. there are many other threads for such discussions - this is a thread to collect requests for datasheet revisions and additions, only.
one last note, and single exception to the above paragraph - since EHX/NS seems to be at least somewhat willing to innovate and create new tube models, i am personally taking this opportunity to provide some requests for what sort of tubes they prioritize the development of in the future. i have been told that these ideas are welcome and will be sent to the technicians as well. so by all means, please share your desires for what sorts of new tube models you'd like to see!
personally, i want to see subminiature pencil tubes, especially the frame grid types, see more focus. they were a brilliant idea too soon overshadowed by the rise of the transistor. just think of how awesome a new line of 6111/6112 style tubes would be! less space needed, more flexibility as to placement, less vulnerability to physical damage, high shock tolerance, lower operating voltages...
I’m not sure how much attention updating the documentation will get until production (and distribution) returns to “normal”. I hope it does, but I’m not holding my breath.
Triode curves.
For a new model? A triode strapped pentode with a 60+W Pd, maybe 25000 to 60000 mhos, 1A current, 5A? peak that works with a plate voltage of 170VDC or lower. Even better if it was cold cathode.
For a new model? A triode strapped pentode with a 60+W Pd, maybe 25000 to 60000 mhos, 1A current, 5A? peak that works with a plate voltage of 170VDC or lower. Even better if it was cold cathode.
I'm a subminiature lover too. It could be nice to have some new production.
6n30pev ( 6h30p-DR) variant could be nice to introduce too.
6n30pev ( 6h30p-DR) variant could be nice to introduce too.
You mean like a hexfet UNset? Where even the upper pentode is replaced by a run of the mill N-channel?
I've never seen a depletion MOSFET or a JFET that had such a low transconductance of 25 mA/V, more like amperes per volt. I've also never seen a MOSFET with triode curves that was useful. The SIT was interesting but is rare and expensive now.
What I want is something like 4 6P45S in parallel in one envelope...
The 170 datasheet is pretty sparse. Some typical operating points like any old datasheet. Like two tubes in ab1 at a few voltages with power output and distortion.
It would be handy to have triode curves for the KT150 and KT170, and ultralinear plate curves for all three.
A valid point maybe at the time of posting but the taxes from a few valves won't buy Putin a new pair of socks and better fitting underware nevermind a main battle tank. Mind, I'd chip in to get him some more comfy kecks, the bugger never smiles, there's something chafing down there maybe?
Having looked at said datasheets as astoufer sais an extensive list of different operating points from triode strapped to PP UL would be a start. Several graphs of Va vs power OP vs distortion, Va /screen grid current etc would be nice too.
What we normally call a "second source" arrangement. That is an agreement that
includes exchange of engineering drawings and specifications and possibly a
license agreement. Yes, without a second source most serious consumers would
avoid these products. As so few actors exist it's even more important.
The 1st thing that needs fixing are the plate curves.
They look like the result of some Frankenstein mix of other tube parts. I suspect the beam former (g3) has too wide a slot in it, giving it some pure tetrode characteristic. If it is going to use the venerable 7AC base Octal socket, then the B+ needs to be limited well below 850V to avoid arcing. Increase the current rating instead. The grid1 to cathode spacing should be kept sufficient to preserve good/great triode curves. The bottle shape is unique, but obviously non functional for supports.
Take a look at the plate curves of some historic tube greats to see what those should look like:
https://frank.pocnet.net/sheets/118/e/EL156.pdf
https://frank.pocnet.net/sheets/137/6/6CB5.pdf
https://frank.pocnet.net/sheets/019/e/EL506.pdf
https://frank.pocnet.net/sheets/123/1/10JA5.pdf
https://frank.pocnet.net/sheets/163/k/KT77.pdf
They look like the result of some Frankenstein mix of other tube parts. I suspect the beam former (g3) has too wide a slot in it, giving it some pure tetrode characteristic. If it is going to use the venerable 7AC base Octal socket, then the B+ needs to be limited well below 850V to avoid arcing. Increase the current rating instead. The grid1 to cathode spacing should be kept sufficient to preserve good/great triode curves. The bottle shape is unique, but obviously non functional for supports.
Take a look at the plate curves of some historic tube greats to see what those should look like:
https://frank.pocnet.net/sheets/118/e/EL156.pdf
https://frank.pocnet.net/sheets/137/6/6CB5.pdf
https://frank.pocnet.net/sheets/019/e/EL506.pdf
https://frank.pocnet.net/sheets/123/1/10JA5.pdf
https://frank.pocnet.net/sheets/163/k/KT77.pdf
Last edited:
I've got 8 Tung-Sol KT170s as well as an Etracer. And I'm building a Class A Push Pull Amp in UL connection.
If anyone's interested in the curves of different connections, capacitance between electrodes of the tube, or other informations. I can offer some help.
It must be a long time before New-Sensor could notice and revise their datasheets. 😵
Just reply to me with the specific operating point you want to know. I'll present you the curves or other informations in my spare time
If anyone's interested in the curves of different connections, capacitance between electrodes of the tube, or other informations. I can offer some help.
It must be a long time before New-Sensor could notice and revise their datasheets. 😵
Just reply to me with the specific operating point you want to know. I'll present you the curves or other informations in my spare time
Well the KT120 datasheet seems to be outright missing its plate curves. The other tubes that have them look awful. They almost look like they took a few (not nearly enough) discrete measurements and then played "connect the dots".
Eimac used to put really, really nice full-page plate curves in their datasheets, and one could do some very accurate calculations directly off the plate curves. I've attached a few examples of the right way to do plate curves. It shows screen current as well, along with a good, high-resolution full-page graph. The 6C21 and 4PR1000 datasheets also shows plate cutoff characteristics, which I think is really nice to have. I know that a lot of the pulse characteristics would be viewed as "useless" by most, but I still think it's nice to have.
The other thing I'd like to see on them is more "recommended parameters", rather than just for class A1 audio amplifier service. Look at almost any other good tube datasheet - Eimac, GE, RCA, etc. Those "recommended parameters" are really handy for preliminary design work to get an idea of where a tube sits without having to pull out the heavy-duty engineering tools. Not as important as good plate curves, but a nice thing to have in the datasheet.
This is just my opinion, but a crappy datasheet reflects quite poorly on the company that makes the product.
Eimac used to put really, really nice full-page plate curves in their datasheets, and one could do some very accurate calculations directly off the plate curves. I've attached a few examples of the right way to do plate curves. It shows screen current as well, along with a good, high-resolution full-page graph. The 6C21 and 4PR1000 datasheets also shows plate cutoff characteristics, which I think is really nice to have. I know that a lot of the pulse characteristics would be viewed as "useless" by most, but I still think it's nice to have.
The other thing I'd like to see on them is more "recommended parameters", rather than just for class A1 audio amplifier service. Look at almost any other good tube datasheet - Eimac, GE, RCA, etc. Those "recommended parameters" are really handy for preliminary design work to get an idea of where a tube sits without having to pull out the heavy-duty engineering tools. Not as important as good plate curves, but a nice thing to have in the datasheet.
This is just my opinion, but a crappy datasheet reflects quite poorly on the company that makes the product.
It's very reasonable to want, but I don't think it's reasonable to expect. The cost and difficulty of relocating the factory (not to mention the workers - it's not like tube manufacturing is a common skill these days) is likely not something which is realistic. Maybe I'm wrong and New Sensor is massively profitable and sitting on a huge wad of cash, but I rather doubt it. The market for tubes isn't that big.
Note that "second source" implicates that another maker of the devices will start producing them, in competition. The benefit for the original maker is customer satisfaction of a second source AND some licensing income from the other maker. It's not a matter of building / relocating a plant.
Getting another factory up and running is great in principle - if you can staff it. Unfortunately, the main ingredient in any successful manufacturing line is people who know how to do the work - and understand WHY their processes work. I’ve seen the effects of the reverse first hand - when upper management thinks they can just put enough documentation in place and find trained monkeys who just follow orders. The wheels fall off eventually and you end up shipping nothing (And spend a year finding the root cause of a minor issue one of the original retired minds could have found in 15 minutes). If you think getting a factory out is hard, try getting people and see how much resistance you run into. You would need to find experts somewhere else in the world/universe - maybe the guy with the blue face that wanted to get Picard to read his “Paper on thermionic transconductance”. He might know how to make a good KT88, and how to keep the assembly line in spec. I don’t, and neither does a recent PH.D graduate. Maybe some of the original experts from the closed down factory in China - but the military probably got all the good ones, and the rest probably found work in the cell phone industry.
The best hope for New Sensor is for all this to blow over and the world return to some version of normal. Maybe then we’ll even get updated datasheets.
The best hope for New Sensor is for all this to blow over and the world return to some version of normal. Maybe then we’ll even get updated datasheets.