You know how they say mr. Lobal "he's not smart but he's persistent"Yes... they try harder... no, that's not it... they have poor hand eye coordination... no... it's umm... maybe they're determined and never give up... or they're just stubborn.
Tube rolling thread | UltraSonic Studios
- Thread starter OctavianH
- Start date
Today I went a little bit on the experimentation side. I tried EL50 with some 6SL7, good results, you infuse some energy into EL50 and make it sounds an idea mode dynamic. But the sound is also slimmer. Then I put EL6 in place of EL50 and kept EL3N as driver. You loose some soundstage and bass, but you earn an idea more energy because of the gain of EL6.
I think all these "red" pentodes are the from the same family and have something in common. So you basically cannot go wrong with any of these and combining them in diverse ways you are not changing too much the signature. You just keep the same sound but work a little bit on the size of the stage and the steroids. This is why I doubt EL6 makes any sense on input near EL50 because I do not quite want more bass and both EL6 and EL3N are close in gain. So I will not try this or at least not now.
While I like this fast energetic sound, I feel it's an idea forced. This is why I consider EL50 a better match for EL3N. Sounds bigger while being more calm in presentation. Here I have a feeling I put on fast forward the recording and while I like fast and intense music, seems an idea fatiguing. Of course, I might lower the gain on input and then EL6 would be perfect.
As I said, all of these are variations of the same sound. Depends on your mood and preference which one you want to use. My experiments are a part of a bigger plan, which is the Pentode Tribute amp, and I experiment a little bit how far and where you can go with the tubes which will be natively supported. Is that enough? That's what I'm trying to figure out.
I would love to hear these connected as pentodes. All say the triode strapping is more romantic while on ultralinear these are sharper and more neutral. Might be very nice for this signature. Maybe one day I will have the chance to experiment this. Now I guess I'll let these a few hours and change, I feel I had too much coffee with all this gain and energy.
If you want to have everything to the extreme, you go for EL51. That one is fast as EL6 and wide as EL50.
I think all these "red" pentodes are the from the same family and have something in common. So you basically cannot go wrong with any of these and combining them in diverse ways you are not changing too much the signature. You just keep the same sound but work a little bit on the size of the stage and the steroids. This is why I doubt EL6 makes any sense on input near EL50 because I do not quite want more bass and both EL6 and EL3N are close in gain. So I will not try this or at least not now.
While I like this fast energetic sound, I feel it's an idea forced. This is why I consider EL50 a better match for EL3N. Sounds bigger while being more calm in presentation. Here I have a feeling I put on fast forward the recording and while I like fast and intense music, seems an idea fatiguing. Of course, I might lower the gain on input and then EL6 would be perfect.
As I said, all of these are variations of the same sound. Depends on your mood and preference which one you want to use. My experiments are a part of a bigger plan, which is the Pentode Tribute amp, and I experiment a little bit how far and where you can go with the tubes which will be natively supported. Is that enough? That's what I'm trying to figure out.
I would love to hear these connected as pentodes. All say the triode strapping is more romantic while on ultralinear these are sharper and more neutral. Might be very nice for this signature. Maybe one day I will have the chance to experiment this. Now I guess I'll let these a few hours and change, I feel I had too much coffee with all this gain and energy.
If you want to have everything to the extreme, you go for EL51. That one is fast as EL6 and wide as EL50.
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Now, there is something more I have to say about "red riding hood". I said all of these are more or less the same signature. It's true but there are some very small differences between them which I suspect are caused by the factory where these were manufactured. I have here 3 types of EL50, all sounding more or less the same.
Since the codes and markings on them are not similar with what I was able to find related to Philips coding, what I do here is pure guess by associating several articles and ebay listings to what I saw at the pieces from my collection. In my view, all these are the same tube but manufactured in different factories. The one branded as EL50 was made in France or Belgium and sounds an idea leaner towards the Adzam/Mazda sound. The ones from left were made in Holland and are an idea creamier. However, these differences might exists only in my brain but I wanted to mention them. In order to avoid differences I paired them based on construction. The ones from left have "I" or "G" near 4654 on the base. If these are factory codes, then:
While I am unsure about everything relating to these, I have observed small similarities between the one from right and the "L"-code 4654K while the ones from left are more "Eindhoven" style sounding. Of course, pure speculation. If anyone really knows more about these date codes and markings on the base, please elighten me.
Since the codes and markings on them are not similar with what I was able to find related to Philips coding, what I do here is pure guess by associating several articles and ebay listings to what I saw at the pieces from my collection. In my view, all these are the same tube but manufactured in different factories. The one branded as EL50 was made in France or Belgium and sounds an idea leaner towards the Adzam/Mazda sound. The ones from left were made in Holland and are an idea creamier. However, these differences might exists only in my brain but I wanted to mention them. In order to avoid differences I paired them based on construction. The ones from left have "I" or "G" near 4654 on the base. If these are factory codes, then:
While I am unsure about everything relating to these, I have observed small similarities between the one from right and the "L"-code 4654K while the ones from left are more "Eindhoven" style sounding. Of course, pure speculation. If anyone really knows more about these date codes and markings on the base, please elighten me.
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Boxes for EL50 (right model in the 3 pieces photo):
Here is the "I" and "G" on the ones with construction like the one from left in 3 pieces photo:
These are looking identical as construction. Ok, that's the complete story and maybe one day I'll know what the trick with these.
Later edit: Look at the one from middle in the 3 pieces photo and then to this Mullard EL32:
I have similar EL2 with this kind of round "swirlwind".
Here is the "I" and "G" on the ones with construction like the one from left in 3 pieces photo:
These are looking identical as construction. Ok, that's the complete story and maybe one day I'll know what the trick with these.
Later edit: Look at the one from middle in the 3 pieces photo and then to this Mullard EL32:
I have similar EL2 with this kind of round "swirlwind".
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Until I will decypher the mysteries of the Philips old codes, I thought if I reached this point to make 2 more experiments, exactly what I did not wanted to try.
First, I put EL6 on input with EL50 and exactly as expected, I added some bass compared with EL3N, but EL6 somehow sounded not so focused, tubey. For sure, it needs more time but from the start I reached by experiment what I was foreseeing by logic. Here most probably 4mA is not a good operating point for EL6, too low.
Then, I said, why not to try a quad of EL6.
Again, tubey and somehow less energetic and focused than EL6 with EL3N. I have no idea why, but every time I try a quad (2+2) of these pentodes of the same type, I never like it. I had the same problem when I tried a quad of EL3N in both stages. These sound good when you have a slimmer sounding type on input with decent gain. In other cases the magic does not happen. Now, I've seen many amps using EL3N everywhere and it might be circuit dependant, but on my amp, success stories are EL3N + EL6 or EL3N + EL50 and from both, EL3N + EL50 remains the most natural sounding to me. Subjective opinions, for sure.
I do not want to spend more time with this, I do not see a potential here. For me EL6 remains an output pentode, at least on this amp.
PS. Why in my experiments all the time the tube with higher Ih has more bass? Tomas told me that lower Ih should not matter, the tube is more efficient. Well ok, tell this to EL32 at 0.2A. Here again, EL3N < EL6 < EL50 in terms of bass.
First, I put EL6 on input with EL50 and exactly as expected, I added some bass compared with EL3N, but EL6 somehow sounded not so focused, tubey. For sure, it needs more time but from the start I reached by experiment what I was foreseeing by logic. Here most probably 4mA is not a good operating point for EL6, too low.
Then, I said, why not to try a quad of EL6.
Again, tubey and somehow less energetic and focused than EL6 with EL3N. I have no idea why, but every time I try a quad (2+2) of these pentodes of the same type, I never like it. I had the same problem when I tried a quad of EL3N in both stages. These sound good when you have a slimmer sounding type on input with decent gain. In other cases the magic does not happen. Now, I've seen many amps using EL3N everywhere and it might be circuit dependant, but on my amp, success stories are EL3N + EL6 or EL3N + EL50 and from both, EL3N + EL50 remains the most natural sounding to me. Subjective opinions, for sure.
I do not want to spend more time with this, I do not see a potential here. For me EL6 remains an output pentode, at least on this amp.
PS. Why in my experiments all the time the tube with higher Ih has more bass? Tomas told me that lower Ih should not matter, the tube is more efficient. Well ok, tell this to EL32 at 0.2A. Here again, EL3N < EL6 < EL50 in terms of bass.
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This morning I had the feeling that my tube amp does not sound good. No problem, I have a solution.
Now, this is indeed something terrible, how they can sell this to people? LOL
Now, this is indeed something terrible, how they can sell this to people? LOL
Today I am trying to make some new friends. Started with GE 6K6 but after 3-4 tries I was not able to obtain something decent from them. Not bad but under what I consider listenable. That grainy midrange kills me. No problem, I switched to Sylvania 6K6, one of the newer pairs.
This one is definitely better, at least with some Tung Sol 6SL7 grey glass. Both GE and Sylvania are on the bright side, but this one is not so harsh sounding. Of course, older pairs of Sylvania 6K6 are better, but this is one of the newer pairs I can live with. And I like a lot the industrial look of the tube.
This one is definitely better, at least with some Tung Sol 6SL7 grey glass. Both GE and Sylvania are on the bright side, but this one is not so harsh sounding. Of course, older pairs of Sylvania 6K6 are better, but this is one of the newer pairs I can live with. And I like a lot the industrial look of the tube.
I wanted to double check if older Sylvania sound different and better. Now, the thing with better is relative, in this hobby everyone has its own truth so...
But indeed, there is a difference and older are closer to my preferences. An idea more bass and more rounded, not a lot, enough to sound right and a smoother midrange. Again, not much, but these sound better.
I have in fact 4 types, judging by getters, but I avoid to consider the getters as a decisive factor, since these rectangle getters are sounding identical with some inverted cup getters I have. And the black glass ones I am unsure if they are Sylvania, since they have some similarities with some Ken-Rad I have. Well, I have no idea.
One thing is for sure, these yellow logo newer pairs are sharper and more sterile sounding. I'll also show what I mentioned as "inverted cup" having no idea how to call these:
But indeed, there is a difference and older are closer to my preferences. An idea more bass and more rounded, not a lot, enough to sound right and a smoother midrange. Again, not much, but these sound better.
I have in fact 4 types, judging by getters, but I avoid to consider the getters as a decisive factor, since these rectangle getters are sounding identical with some inverted cup getters I have. And the black glass ones I am unsure if they are Sylvania, since they have some similarities with some Ken-Rad I have. Well, I have no idea.
One thing is for sure, these yellow logo newer pairs are sharper and more sterile sounding. I'll also show what I mentioned as "inverted cup" having no idea how to call these:
There's something about the light coming out from this tube. These 6K6 are very nice looking and lightning.
Time to make some new experiments. Let me present you the EBL1 tube:
Why am I showing you this? Well, I wanted to have more EL3N but the greedy bastards always bid on them. And you know, I do not want to spend too much on tubes because I always have better choices to make. So I went as always sideways, searching for EL3N where there was no EL3N in the name so the greedy bastards will not counter bid me. Well, no problem, the old european pentodes help me because they know I want to make them a tribute amp one day. EBL1 is a double-diode pentode, but the pentode is basically an EL3N. Excellent, the only problem was the pinout, a little bit different than my other choices I have used until now. But well, I had a very simple solution for that. What do we have here?
I tell you, an EL2 pinout where the 2 unused pins are the Diode Anodes. So these work without problems on any EL2 adapter. And are cheaper. And nobody cares about them. No problem, I am here to help. I measured these and indeed went around EL3N values, an idea stronger. NOS NIB or hell knows, but are an idea 10% stronger that my max measured EL3N which were also NOS NIB. So the same tube, more or less, in my view.
Now, let's put it to work, at first as an output pentode.
Biasing for 200V/20mA at around -5V this works perfectly fine in the EL2 adapters. Maybe the wire is an idea shorter, adapters were made for the small EL2. Soundwise, WOW. I am not making any bold statement, might be close to EL3N but coming from 6K6 well, we entered again into gods realm. Not enough soundstage, bass and so on but this is not bothering me anymore because I know what are these, these are inputs for the kings EL50 or EL51. So now I just play them to let them start coming back to life, and even now, the sound quality is excellent. Later they will go where they should, on input, now I am just happy I extended an idea the compatibility list of my Old European Pentode Tribute Amp. With a wider variety on input which has higher gain, that one will be, for sure, a much more flexible and entertaining amp.
Good progress. Now I can let the guys fight for EL3N and make my own experiments and tries here. I have, of course, a second pair incoming because, you know... today I was greedy. Guilty as charged! At least the price was the correct one.
Why am I showing you this? Well, I wanted to have more EL3N but the greedy bastards always bid on them. And you know, I do not want to spend too much on tubes because I always have better choices to make. So I went as always sideways, searching for EL3N where there was no EL3N in the name so the greedy bastards will not counter bid me. Well, no problem, the old european pentodes help me because they know I want to make them a tribute amp one day. EBL1 is a double-diode pentode, but the pentode is basically an EL3N. Excellent, the only problem was the pinout, a little bit different than my other choices I have used until now. But well, I had a very simple solution for that. What do we have here?
I tell you, an EL2 pinout where the 2 unused pins are the Diode Anodes. So these work without problems on any EL2 adapter. And are cheaper. And nobody cares about them. No problem, I am here to help. I measured these and indeed went around EL3N values, an idea stronger. NOS NIB or hell knows, but are an idea 10% stronger that my max measured EL3N which were also NOS NIB. So the same tube, more or less, in my view.
Now, let's put it to work, at first as an output pentode.
Biasing for 200V/20mA at around -5V this works perfectly fine in the EL2 adapters. Maybe the wire is an idea shorter, adapters were made for the small EL2. Soundwise, WOW. I am not making any bold statement, might be close to EL3N but coming from 6K6 well, we entered again into gods realm. Not enough soundstage, bass and so on but this is not bothering me anymore because I know what are these, these are inputs for the kings EL50 or EL51. So now I just play them to let them start coming back to life, and even now, the sound quality is excellent. Later they will go where they should, on input, now I am just happy I extended an idea the compatibility list of my Old European Pentode Tribute Amp. With a wider variety on input which has higher gain, that one will be, for sure, a much more flexible and entertaining amp.
Good progress. Now I can let the guys fight for EL3N and make my own experiments and tries here. I have, of course, a second pair incoming because, you know... today I was greedy. Guilty as charged! At least the price was the correct one.
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Gaining some trust that these work perfectly in my EL2 adapters, I had to make a small try on the "final" usage scenario. But never do this at home, unless you do really know exactly how your amp is wired, adapters are made and so on. In short, never do this. I am crazy, and I risk because my amp was custom made to me and I know every bit of it related to pinouts and how to bias manually these.
So, here we are, EBL1 with EL50. EL2->KT88 are on top of 6V6->6J5. I checked in detail these adapters in the past, made tables with each pin is connected to each and so on.
Works fine and sounds excellent. Not as warm at first sight as with other EL3N but here we have some new tubes. It will take months to decypher the secrets of EBL1, and differences between RT and WIRAG or between EL3N and EBL1, but now I can say RT are sounding very good, rich and do not have that "dark" tone of other RT tubes. Are these an exception? Were they manufactured elsewhere? I have no idea. I just find some similarities between what I see on top of the EBL1 and the EL50 I have (in the previous posts there is a 3 pieces photo showing 3 types of 4654/EL50, the one from right was branded EL50 and had a kind of similar construction). But again, I am guessing.
One thing is for sure, EBL1 was a big success for me and might be an opener of a longer road.
Later edit: Forgot to mention, for input I went to around -7V for 180V/4mA. As a reference, EL3N was around -6.5V so "stronger" tubes EBL1 vs EL3N.
So, here we are, EBL1 with EL50. EL2->KT88 are on top of 6V6->6J5. I checked in detail these adapters in the past, made tables with each pin is connected to each and so on.
Works fine and sounds excellent. Not as warm at first sight as with other EL3N but here we have some new tubes. It will take months to decypher the secrets of EBL1, and differences between RT and WIRAG or between EL3N and EBL1, but now I can say RT are sounding very good, rich and do not have that "dark" tone of other RT tubes. Are these an exception? Were they manufactured elsewhere? I have no idea. I just find some similarities between what I see on top of the EBL1 and the EL50 I have (in the previous posts there is a 3 pieces photo showing 3 types of 4654/EL50, the one from right was branded EL50 and had a kind of similar construction). But again, I am guessing.
One thing is for sure, EBL1 was a big success for me and might be an opener of a longer road.
Later edit: Forgot to mention, for input I went to around -7V for 180V/4mA. As a reference, EL3N was around -6.5V so "stronger" tubes EBL1 vs EL3N.
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Now the 1M$ question is how to decypher the RT date coding.
So we have:
K6.B-Fm-48.
K6 = EBL1 tube type
F = Suresnes
B = ?
m-48 might be the actual date? I doubt because Fm is common to many tubes I have.
So we have:
K6.B-Fm-48.
K6 = EBL1 tube type
F = Suresnes
B = ?
m-48 might be the actual date? I doubt because Fm is common to many tubes I have.
https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/post-15729117
I've seen this getter type called 'pill getter' or as in the link above.
Time to make some new experiments. Let me present you the EBL1 tube:
Why am I showing you this? Well, I wanted to have more EL3N but the greedy bastards always bid on them. And you know, I do not want to spend too much on tubes because I always have better choices to make. So I went as always sideways, searching for EL3N where there was no EL3N in the name so the greedy bastards will not counter bid me. Well, no problem, the old european pentodes help me because they know I want to make them a tribute amp one day. EBL1 is a double-diode pentode, but the pentode is basically an EL3N. Excellent, the only problem was the pinout, a little bit different than my other choices I have used until now. But well, I had a very simple solution for that. What do we have here?
I tell you, an EL2 pinout where the 2 unused pins are the Diode Anodes. So these work without problems on any EL2 adapter. And are cheaper. And nobody cares about them. No problem, I am here to help. I measured these and indeed went around EL3N values, an idea stronger. NOS NIB or hell knows, but are an idea 10% stronger that my max measured EL3N which were also NOS NIB. So the same tube, more or less, in my view.
Now, let's put it to work, at first as an output pentode.
Biasing for 200V/20mA at around -5V this works perfectly fine in the EL2 adapters. Maybe the wire is an idea shorter, adapters were made for the small EL2. Soundwise, WOW. I am not making any bold statement, might be close to EL3N but coming from 6K6 well, we entered again into gods realm. Not enough soundstage, bass and so on but this is not bothering me anymore because I know what are these, these are inputs for the kings EL50 or EL51. So now I just play them to let them start coming back to life, and even now, the sound quality is excellent. Later they will go where they should, on input, now I am just happy I extended an idea the compatibility list of my Old European Pentode Tribute Amp. With a wider variety on input which has higher gain, that one will be, for sure, a much more flexible and entertaining amp.
Good progress. Now I can let the guys fight for EL3N and make my own experiments and tries here. I have, of course, a second pair incoming because, you know... today I was greedy. Guilty as charged! At least the price was the correct one.
So "Pill getter" is the name. Indeed it is similar with some russian tubes getter but I have seen it on several european tubes. For example ATS25 has it.
But not only, for example a variation of it is seen on Visseaux 6N7:
Here on Fivre 76:
And here on Fivre 6N7:
And I have, most probably, also other examples. These are coming to my mind now.
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