[UntilThen]

This is Korean 300b tube.

 

[OctavianH]

And this is KT170, new shipment arrived:

 

[OctavianH]

I bet you guys wanted some action, isn't it? Too many beers, steaks, off topic. So, let's have some action and there is no better and more beautiful action than tube rolling!

So, for this Saturday I said, let's have something exotic, let's forget about my principle of "no adapters, no top cap". Let's make something beautiful, something RED guys!

Ok, here we are, Philips EL3N in dual adapter to 6SN7 with Mullard EL32 on output in adapter to 6V6! That's the most uncommon combo until now.
What was really strange is that I was expecting around -7.5V at 180V/4mA according to the datasheet of EL3 (couldn't find graphs for EL3N but I think these are similar)

Well, the bias went around -6.3V this making possible the use of this dual EL3N input combination at my fixed grid bias set for 6J5.

Regarding the signature, this takes Eternity a little bit towards the OTL style of sound, romantic, euphonic, less detail, more tubey than analytic. EL32 is a very special tube for me, very emotional, I was always using it to compensate some 6AS7G or even KT tubes on Elise. I miss the punchy articulated bass, but the voices and piano are better, and overall it is a warm sound. Cannot say I dislike it, I was hoping to add some romance to my table with KT77 but the story from yesterday was not so successful. I will not use this on a daily basis, it was only a demonstration and I wanted to verify my bias voltages, but dual EL3N can be a solution to 6V6 or 6L6 lack of power. Today I remembered the beauty of the EL tubes on neutral/analytical amplifiers. These bring back emotion at the price of clarity and detail. On Elise which was a warm amplifier I never wanted to use these, even if I have 8 pieces of EL3N. Here on Eternity, EL tubes are definitely a nice experience.

Grid biases:
2 x EL3N -> 6SN7: -6.3V (180V/4mA)
EL32 -> 6V6: -17V (200V/20mA)

 

[OctavianH]

Going back halfway to EL32 and L63, half of the euphony was gone but a more clean sound came back. Eternity is responsive to tube rolling. I think a bigger quantity of that euphony was caused by the EL32, because outputs seem to be a little bit more pronounced influence in overall tone, but even in this case the inputs have for sure, their own influence. So both stages affect the signature and tube rolling makes sense on both levels. Problematic are the adapters, I will think if it makes sense to buy EL3N->6V6, EL11->6V6 and so on. Or maybe just a pair of 6M6G. Having countless of possibilities I think I have to focus, if possible, on "no adapter" combos. And in the end, I wanted an amplifier for KT66, so a driver to make the sound more emotional while the output remains KT66 is one of my main goals.

 

[OctavianH]

Last try for today, EL3N with KT88.

It is a little bit too warm for me, the same as with KT66. But might be a very nice combo for more neutral headphones like HD800. I would not use this on T1.2.
Conclusion of today's experiments is that Eternity is a good place to try EL tubes, EL3N sounds good, warm, melow and EL32 in output is also a quite good solution.

What next? Well, I might try sometimes in the future EL38 as output, another thing would be EL34 and then some more 6J5/6C5 variants. But of course, we will see.
In the meantime I hunt a pair of Psvane KT88T2 to have a spare part, these are so good I do not want to part with them and @UntilThen is making them famous.
More than this, I think Psvanes are not produced anymore, let's hope I'll find a new pair. If not, these should last me a lifetime at 200V/20mA how we use them in Eternity.

Ok, too much on topic, back to Beer mode. I've turned my Tube rolling switches OFF, EL3N (in dual adapter to 6SN7) works perfectly with my fixed bias and this pair of KT88 biases the same as KT66. Tube rolling off means beer rolling on. We will see in the next days what will happen, I wait for the next Eternity to be released so a more wise and experienced guy will come into the light of the stage. If we both have the same grid bias points for several tube types I'll update the first post and table with some values we consider decent to be used in Eternity for people without a tube tester. Let's hope we will be right, but about this we will know more in the next months.

Now, time for me to go drink a beer with this guy:

 

[UntilThen]

I have a pair of Mullard EL32 coke bottle smoke glass but not sure if I get to use it again. I intend to keep Odyssey look clean and smart.

 

[SonicTrance]

@OctavianH
Nice to read your impressions and that you're having fun tube rolling!

I have a pair of Mullard EL32 coke bottle smoke glass but not sure if I get to use it again. I intend to keep Odyssey look clean and smart.

Not in Odyssey you can't. At least not as power tubes.

 

[UntilThen]

Not in Odyssey you can't. At least not as power tubes.

No worries, I am not concerned about wanting to use EL32 in Odyssey. If I could use no other power tubes but just KT88 and EL34, I'm perfectly fine with that. These tubes are the nucleus on which the others spin around in orbit.

I'm on the other hand more engrossed with how I want the front panel of Odyssey to look. I'm debating.... hard decision here. I need Jon Iver.

A


B


C

 

[hpamdr]

I like the simplicity of C just missing output headphone plug also on front... unless you want it on top or use your speaker wire only..

If you want output signal meter, both A/B have on common that the meter is in front of the input/driver tube. 3 knobs Volume, and two function switches.
If you do not have two additional switches, you can also group meters side by side, then knob, then plugs ...

@SonicTrance Tomas is for sure better than me and next to the design, you have the usability to take in consideration.

What i see from @OctavianH photo is that the nice glow of the meters add visual enjoyment and balance the light. It is not useful for me for me but very nice to see !

 

[OctavianH]

I'm on the other hand more engrossed with how I want the front panel of Odyssey to look.

It depends on how many elements you want to have on the front panel. I personally think Eternity looks better than Citadel by alternating switch with meter.

Regarding tubes, well, you may be surprised with how some tubes work on these amplifiers. My core tubes were KT66 and 6J5 and now I use KT88 and EL3N.

 

[hpamdr]

It depends on how many elements you want to have on the front panel. I personally think Eternity looks better than Citadel by alternating switch with meter.

Citadel is larger than Eternity and in both configuration the meter is in front of an input tube for each side... For your compact eternity the best match is he one you have

Regarding tubes, well, you may be surprised with how some tubes work on these amplifiers. My core tubes were KT66 and 6J5 and now I use KT88 and EL3N.

Next try should be EL11 if you have tube and adapter to 6J5 and with KT88 (this is in Euforia a good and powerful match).
And next try 6SL7 with EL32 with relaxing music.... or some 60/70 pop like :

 

[OctavianH]

I do not have any EL11 adapters except single 6SN7 which is not usable. 6SL7 with EL32 would be possible soon.

 

[OctavianH]

Citadel is larger than Eternity and in both configuration the meter is in front of an input tube for each side... For your compact eternity the best match is he one you have

Yes, meter in front of a tube socket is more a matter of finding space on the inside for the meter. My small chasis created a lot of problems, because I also have the stepped attenuator which is quite big. Tomas was a magician to fit all these inside that small chasis.

Later edit:

Morning coffee with a view, EL3N + KT66:

This combo adds some distortion and bite to the electric guitar. For sure not for classical or pop, but on specific genres which are more aggressive, the polished and clean sound of Eternity and 6J5 is not the perfect choice. Well, this one is the solution in that case.

As a sidenote about this specific EL3N double adapter to 6SN7 and EL3N in Eternity: This adapter is a monstrosity, I broke one using it 2 times in Elise years to have that 6 x EL3N everyone tried and now I have only this one. Besides the fact that the EL3N socket itself is hard to use, these cheap plastic ones are even harder. But, the adapter allows rotation of the 6SN7 base and in this particular case of an amplifier with the guiding pin of the tube sockets on the left (as you look on it) it is very useful.
Now, regarding EL3N, if I turn the volume to 0 I hear a very small hum. But this is a problem of my EL3N tubes or maybe adapters, I had the same on Elise. I do not think this will damage in any way Eternity as it is barely hearable, but I thought it is worth mentioning. Eternity is dead silent, but this double EL3N combo is not. EL32 were dead silent too.

And in the end, since we are at the EL3N chapter some fine things to read:

EL3N Single Ended Sakuma style

and some nice comments here:

Old Europian Pentodo Philips EL3N

 

[hpamdr]

Yes, meter in front of a tube socket is more a matter of finding space on the inside for the meter. My small chasis created a lot of problems, because I also have the stepped attenuator which is quite big. Tomas was a magician to fit all these inside that small chasis.

Later edit:

Morning coffee with a view, EL3N + KT66:



This combo adds some distortion and bite to the electric guitar. For sure not for classical or pop, but on specific genres which are more aggressive, the polished and clean sound of Eternity and 6J5 is not the perfect choice. Well, this one is the solution in that case.

As a sidenote about this specific EL3N double adapter to 6SN7 and EL3N in Eternity: This adapter is a monstrosity, I broke one using it 2 times in Elise years to have that 6 x EL3N everyone tried and now I have only this one. Besides the fact that the EL3N socket itself is hard to use, these cheap plastic ones are even harder. But, the adapter allows rotation of the 6SN7 base and in this particular case of an amplifier with the guiding pin of the tube sockets on the left (as you look on it) it is very useful.
Now, regarding EL3N, if I turn the volume to 0 I hear a very small hum. But this is a problem of my EL3N tubes or maybe adapters, I had the same on Elise. I do not think this will damage in any way Eternity as it is barely hearable, but I thought it is worth mentioning. Eternity is dead silent, but this double EL3N combo is not. EL32 were dead silent too.

Some El3N tubes are prone to heating noise but usually not loud enough to be very annoying.
Yes EL3N add some kind of echo/harmonic when used as driver/input this is even more accentuated with KT66 or EL3N as output. But it add some distortion that some find nice and specially because it create an effect that could enhance soundstage at least in Elise..
The one that use dynamic and sensitive headphone can find it a bit "too much" but at the end it is all a personal choice/taste and synergy.

 

[OctavianH]

Some El3N tubes are prone to heating noise but usually not loud enough to be very annoying.
Yes EL3N add some kind of echo/harmonic when used as driver/input this is even more accentuated with KT66 or EL3N as output. But it add some distortion that some find nice and specially because it create an effect that could enhance soundstage at least in Elise..
The one that use dynamic and sensitive headphone can find it a bit "too much" but at the end it is all a personal choice/taste and synergy.

Yes, EL3N add some distortion which in my specific case is needed. And you were right when you advised me to try 6L6 with EL3N or EL11. If 6L6 felt underpowered with 6J5/6SN7 with EL3N as input it starts to sound better. So yeap, EL3N is not very detailed, not very clean, somehow a warmer variant of EL11, but in some cases, when the other pair sounds dull or it is too polite, well, it does the trick. Honestly these still sell at around 25 EUR/piece at Acoustic Dimension in Holland which seems to me a decent price for what they can do. I never liked these because Elise was too warm for them. I guess they were better in Euforia or more neutral amplifiers. In my case, EL3N + Elise + T1.2 was for sure the wrong path. Now I start to reconcile my relationship with them. Not spectacular but useful to have at home.