[Isaacc7]

I'm still working with the 6v6gt outputs. Settled on 280v 30ma in Ultralinear and 280v 35ma in triode. Ultralinear is more forward and cleaner sounding. The triode mode is fuller, slightly warmer, but more closed in.

I cycled through a variety of input tubes with triode mode:
1) Sylvania tall 7n7. Generally pretty good, well balanced.
2) Mullard ecc31 w/adapter. flat, mushy, clearly isn't a good match like they aren't compatible electrically.
3) Tungsol 6c8g. Dynamic, kind of "exciting" sounding. But a bit hot on the high end and fatiguing.
4) RCA 6sn7. Dry, wooly bass, ugh.
5) Raytheon 6f8g T plates. Probably the best combo. a bit more accurate sounding than the 7n7 and a better more solid bass.

In the end though, none of them really clicked. Everything still sounded too hot, too forward. That might change when I can try my 12sn7 tubes once I get the cables for the heater supply.

Then it occurred to me, instead of trying to tame the Ultralinear mode why not liven up the triode mode? My other amp sounded best with 6sn7 and equivalent. The 6sl7 always sounded hot and thin in it. I remember Tomas saying that the amp might actually be optimized for the 6sl7. Grabbed the easiest to get 6sl7, a pair of Sylvania brown base 6sl7w. Yup, these with the 6v6gt in triode are a good combo. It brought back the top end and tightened up the bass. Now I'm getting everything! Remember that the bottom getter Sylvania 6sl7 tall bottle was a bit more refined sounding so went and dug those up. Ugh, one of them was dead! Didn't light up at all! Found another and ahhhh... Yup, these are the perfect partner. They are smoother and "classier" sounding than the other Sylvania JAN brown base. This still isn't a warm sound but it is a very clear and transparent sound. Listened to "Ultraviolence" by Lana Del Ray and "Begin to Hope" by Regina Spektor. Their voices are pure and expressive and the rest of the mix supports them. Will probably try "The Trinity Sessions" by The Cowboy Junkies later tonight to finish off the female singers theme.

Tomorrow I'll try the 7c5 again now that I have the settings figured out. The 6v6gt seemed much warmer so I doubt the 7c5 will work with the same input tubes. I have some more exotic 12sl7 from Brimar and Tungsram to try in the future. Next week I'll be traveling for Thanksgiving but should be back on the tube journey the week after.

 

[Isaacc7]

Went ahead and put the JAN 7c5 Sylvania tubes in. First thing I noticed was that they drew way more current than the 6v6gt tubes despite supposedly being exact replacements. With some adjustment I run them at the same triode settings of 280v 35ma with the bottom getter tall Sylvania 6sl7. Big change, and for the better I think. Soundstage is deeper, better detail, more air. Going to leave this combo in until I get back from thanksgiving travel. Hope I'll be able to focus on family stuff and not dreams of my amp while I'm away lol.

 

[OctavianH]

Were you thinking about a push pull amp? Not sure if whatever I end up thinking about Ultralinear will translate to a single ended amp.

I was thinking in general if triode mode and ultralinear in the same amp would be a benefit for me. But later Tomas told me that this feature is available only on classic designs like Odyssey. So it goes somehow out of my scope because the reason I've chosen UltraSonic was the new approach and modern designs. I am still documenting on this.

So I don't think getting 12v outputs are really worth it unless you are really jonesing for the gu50. 12v inputs are an easy decision though. So much more reasonably priced. And I'm not up on this but I think that would also open up more possibilities with 9 pin tubes as well.

I try to stay out of the russian/chinese market because I have a lot of better options. But TT22 and 1625 and so on might be useful, and who knows what we will find in the future. -13V maximum on input for grid bias was enough for me in 2020 but later I said why not to try 37 and realized I cannot bias it. Not a big problem but you know my theory: maximum flexibility if possible. So why renounce on something you might find useful tomorrow.

I'm still working with the 6v6gt outputs. Settled on 280v 30ma in Ultralinear and 280v 35ma in triode. Ultralinear is more forward and cleaner sounding. The triode mode is fuller, slightly warmer, but more closed in.

My first impression of Eternity vs Elise was "much wider soundstage and more clarity and clean sound". But keep in mind that Eternity is a modern design, I have a feeling Odyssey is more tubey and the UL mode of it is close to what my Eternity sounds. So... we are discussing here most probably wine and whiskey. LOL

I cycled through a variety of input tubes with triode mode:
1) Sylvania tall 7n7. Generally pretty good, well balanced.
2) Mullard ecc31 w/adapter. flat, mushy, clearly isn't a good match like they aren't compatible electrically.

Same here, I never really got into Mullard on Eternity. Does not sound very natural, it has a sweetness but somehow forced. At first I was pleased by novelty, later I realized it is not quite my type of sound and definitely prefer GEC and Brimar. Tried here on output Mullard 807 and on input ECC31, ECC32 and ECC35. Of course there is, like always, an exception: EL34 xf2 which is for me one of the best EL34 and in my opinion does not sound as "veiled" as the rest I've mentioned. Also ECC35 is somehow nice, closer to what I like than ECC31 and ECC32. I have a few pairs of Mullard 6C4 and some 12A*7 but I had no time for them yet. So I cannot say anything about those.

5) Raytheon 6f8g T plates. Probably the best combo. a bit more accurate sounding than the 7n7 and a better more solid bass.

I find 6SN7, 6F8G, 7N7 and 6CG7 sounding more or less the same. So not quite my type (with 3 exceptions: Forton 6H8C pre '55, Raytheon VT-231 and Brimar 6SN7GT which all go somehow off the classic sound of the others). And here it is also a simple electrical explanation, as far as I know all of these have the same electrical parameters except different base. So, makes sense somehow.

Hope I'll be able to focus on family stuff and not dreams of my amp while I'm away lol.

Enjoy the weekend, you'll need at least one year to understand something from such an amp. I started a few months ago to really get an idea about what is happening. At first I thought "I already know how x will sound" and was surprised to learn that the specific tube sounded different in Eternity compared to Elise. So I had to make a tour of my collection to get an idea about each one. Then I tried to make pairings based on what I've learned in the first phase. After I got 5-6 pairings I considered worth listening more, I started the next phase of letting each one 1-2 weeks and see where this goes... But in my case it was simple, you have several more variables to handle: UL/Triode mode, 12.6/6.3V (not sure if sound signature is different based on heater current) and so on.

I am trying this morning a quite epic combo: Brimar CV1932 with GEC KT66.

I like how these warmer GEC outputs (ATS25, KT66 grey, KT61) sound with Brimar and changing type (6J5 to 6SN7) is just slightly adding or removing something, the overal signature... remains based on what I call "house sound". Of course these do not quite work with KT88 or KT66 clear glass.

And we have the first deceased in the family, well my Philips ECG 6SN7WGTA I was keeping as placeholder on the dual triode slot, just to "light up" is dead. Well, we replaced it with a socket saver.

Not a big problem for me, I never liked this either, actually I guess it was the worse 6SN7 I've tried. I have somewhere another one, in one of the boxes, stored because I doubt I'll even listen to it. I might grab it to put it on the socket. I wonder if this feature of "all tubes light" where the one not selected by the input selector (single/double triode) has only the filament connected is somehow damaging something. I doubt, I guess it was just a tube which decided to die after some years. I doubt it had any damaging effect on the amp since the input selector was on single triode, for the Brimars. So I guess the filament died or hell knows. Maybe I'll shock the community by chosing there a GE tube, I have somewhere a GE 6SN7GT I am sure the guys will love. LOL

 

[Isaacc7]

I was thinking in general if triode mode and ultralinear in the same amp would be a benefit for me. But later Tomas told me that this feature is available only on classic designs like Odyssey. So it goes somehow out of my scope because the reason I've chosen UltraSonic was the new approach and modern designs. I am still documenting on this.

I try to stay out of the russian/chinese market because I have a lot of better options. But TT22 and 1625 and so on might be useful, and who knows what we will find in the future. -13V maximum on input for grid bias was enough for me in 2020 but later I said why not to try 37 and realized I cannot bias it. Not a big problem but you know my theory: maximum flexibility if possible. So why renounce on something you might find useful tomorrow.

My first impression of Eternity vs Elise was "much wider soundstage and more clarity and clean sound". But keep in mind that Eternity is a modern design, I have a feeling Odyssey is more tubey and the UL mode of it is close to what my Eternity sounds. So... we are discussing here most probably wine and whiskey. LOL

Same here, I never really got into Mullard on Eternity. Does not sound very natural, it has a sweetness but somehow forced. At first I was pleased by novelty, later I realized it is not quite my type of sound and definitely prefer GEC and Brimar. Tried here on output Mullard 807 and on input ECC31, ECC32 and ECC35. Of course there is, like always, an exception: EL34 xf2 which is for me one of the best EL34 and in my opinion does not sound as "veiled" as the rest I've mentioned. Also ECC35 is somehow nice, closer to what I like than ECC31 and ECC32. I have a few pairs of Mullard 6C4 and some 12A*7 but I had no time for them yet. So I cannot say anything about those.

I find 6SN7, 6F8G, 7N7 and 6CG7 sounding more or less the same. So not quite my type (with 3 exceptions: Forton 6H8C pre '55, Raytheon VT-231 and Brimar 6SN7GT which all go somehow off the classic sound of the others). And here it is also a simple electrical explanation, as far as I know all of these have the same electrical parameters except different base. So, makes sense somehow.

Enjoy the weekend, you'll need at least one year to understand something from such an amp. I started a few months ago to really get an idea about what is happening. At first I thought "I already know how x will sound" and was surprised to learn that the specific tube sounded different in Eternity compared to Elise. So I had to make a tour of my collection to get an idea about each one. Then I tried to make pairings based on what I've learned in the first phase. After I got 5-6 pairings I considered worth listening more, I started the next phase of letting each one 1-2 weeks and see where this goes... But in my case it was simple, you have several more variables to handle: UL/Triode mode, 12.6/6.3V (not sure if sound signature is different based on heater current) and so on.

I am trying this morning a quite epic combo: Brimar CV1932 with GEC KT66.



I like how these warmer GEC outputs (ATS25, KT66 grey, KT61) sound with Brimar and changing type (6J5 to 6SN7) is just slightly adding or removing something, the overal signature... remains based on what I call "house sound". Of course these do not quite work with KT88 or KT66 clear glass.

And we have the first deceased in the family, well my Philips ECG 6SN7WGTA I was keeping as placeholder on the dual triode slot, just to "light up" is dead. Well, we replaced it with a socket saver.



Not a big problem for me, I never liked this either, actually I guess it was the worse 6SN7 I've tried. I have somewhere another one, in one of the boxes, stored because I doubt I'll even listen to it. I might grab it to put it on the socket. I wonder if this feature of "all tubes light" where the one not selected by the input selector (single/double triode) has only the filament connected is somehow damaging something. I doubt, I guess it was just a tube which decided to die after some years. I doubt it had any damaging effect on the amp since the input selector was on single triode, for the Brimars. So I guess the filament died or hell knows. Maybe I'll shock the community by chosing there a GE tube, I have somewhere a GE 6SN7GT I am sure the guys will love. LOL

That particular 6sn7 is known to be terrible for audio. Philips branded Sylvania in general has a pretty bad reputation. I haven’t had any trouble hearing differences between different versions of *sn7 tubes and their equivalents. Different circuits will of course sound better/worse with different tubes but the 6sn7 family has a (well deserved IMO) reputation as a good sounding tube. My go-to Raytheon 6f8g has the same plate structure as the vt231 so it wouldn’t surprise me if they shared a sonic signature.

Some of the Russian power tubes are really good. I am a big fan of the current “Gold Lion” KT66 and “Tung-Sol” 7581a. I’ve also heard nothing but good things about the Gold Lion KT77. I will admit to a prejudice against Russian small signal tubes. Haven’t heard one that I actually liked. It is what has prevented me from pursuing the Meltz bandwagon. Just as well, I have too many tubes as it is lol.

I have a pretty positive view about Mullard in general. I really like the 807 from them. I also liked what I heard of their 6aq5. I bought the ecc31 based on the advice that with the right adapter it would essentially be the same as the crazy expensive ecc32. That tube has quite a reputation for sound quality. Sadly, neither of my amps has been sonically compatible. At least so far, maybe it’l be different with a different set of output tubes. The problems I have aren’t ones of taste it is basic electric compatibility. In my SEP amp the ecc31 sounded really phasey and had a crazy forward midrange. In Odyssey they sound for all the world like they simply can’t drive the 7c5. Dynamics, frequency range, tonality, all heavily compressed. There are some big differences between an ecc32 and a 6sn7 electrically. All I ever heard about was the increased heater demands. I’m still hoping I will be able to experience what so many other people have with those tubes. Also want my Visseux 11n7 to be in my quiver. So far they have suffered the same issues as the ecc31.

 

[OctavianH]

I bought the ecc31 based on the advice that with the right adapter it would essentially be the same as the crazy expensive ecc32.

I can confirm that, at least on my amplifier, ECC31 sounded the same as ECC32.

 

[Isaacc7]

Switched to the Raytheon T plate 6f8g on the input. The 6sl7 is magical as long as the recording is immaculate. I have several favorite recordings that have a lot of high frequency energy and the 6sl7 really brought it out. The Raytheon 6f8g is a little more even keeled.

Think I have the sound of these JAN 7c5 figured out, at least in triode. Many people associate the 300b with a warm, euphonic sound. And that is in fact how early amplifiers that used them sounded as well as amps based on the same circuits. More modern circuits and push pull take advantage of the 300b’s (and other low power directly heated triodes) inherent low distortion. I think those amps have more of a “pure” sound than romantic. Transparency, air, and purity of tone instead of euphonic creaminess. That’s the kind of sound I’m getting from these JAN 7c5 in triode push pull. That thought crystallized while reading some posts on Audio Asylum where some of the old hands compared 6v6g in triode to the PX4. I haven’t heard a PX4 based amp but my current configuration does remind me of some systems I’ve heard built around push pull 300b and 2a3 amps.

This is in contrast to my experience of the same tube in my SEP amp. I am used to hearing a slightly warm, kind of romantic sound. So yeah, looks I’ll have to relearn what my tubes “sound like” in my new amp. Should be fun!

 

[mordy]

I was thinking in general if triode mode and ultralinear in the same amp would be a benefit for me. But later Tomas told me that this feature is available only on classic designs like Odyssey. So it goes somehow out of my scope because the reason I've chosen UltraSonic was the new approach and modern designs. I am still documenting on this.

I try to stay out of the russian/chinese market because I have a lot of better options. But TT22 and 1625 and so on might be useful, and who knows what we will find in the future. -13V maximum on input for grid bias was enough for me in 2020 but later I said why not to try 37 and realized I cannot bias it. Not a big problem but you know my theory: maximum flexibility if possible. So why renounce on something you might find useful tomorrow.

My first impression of Eternity vs Elise was "much wider soundstage and more clarity and clean sound". But keep in mind that Eternity is a modern design, I have a feeling Odyssey is more tubey and the UL mode of it is close to what my Eternity sounds. So... we are discussing here most probably wine and whiskey. LOL

Same here, I never really got into Mullard on Eternity. Does not sound very natural, it has a sweetness but somehow forced. At first I was pleased by novelty, later I realized it is not quite my type of sound and definitely prefer GEC and Brimar. Tried here on output Mullard 807 and on input ECC31, ECC32 and ECC35. Of course there is, like always, an exception: EL34 xf2 which is for me one of the best EL34 and in my opinion does not sound as "veiled" as the rest I've mentioned. Also ECC35 is somehow nice, closer to what I like than ECC31 and ECC32. I have a few pairs of Mullard 6C4 and some 12A*7 but I had no time for them yet. So I cannot say anything about those.

I find 6SN7, 6F8G, 7N7 and 6CG7 sounding more or less the same. So not quite my type (with 3 exceptions: Forton 6H8C pre '55, Raytheon VT-231 and Brimar 6SN7GT which all go somehow off the classic sound of the others). And here it is also a simple electrical explanation, as far as I know all of these have the same electrical parameters except different base. So, makes sense somehow.

Enjoy the weekend, you'll need at least one year to understand something from such an amp. I started a few months ago to really get an idea about what is happening. At first I thought "I already know how x will sound" and was surprised to learn that the specific tube sounded different in Eternity compared to Elise. So I had to make a tour of my collection to get an idea about each one. Then I tried to make pairings based on what I've learned in the first phase. After I got 5-6 pairings I considered worth listening more, I started the next phase of letting each one 1-2 weeks and see where this goes... But in my case it was simple, you have several more variables to handle: UL/Triode mode, 12.6/6.3V (not sure if sound signature is different based on heater current) and so on.

I am trying this morning a quite epic combo: Brimar CV1932 with GEC KT66.



I like how these warmer GEC outputs (ATS25, KT66 grey, KT61) sound with Brimar and changing type (6J5 to 6SN7) is just slightly adding or removing something, the overal signature... remains based on what I call "house sound". Of course these do not quite work with KT88 or KT66 clear glass.

And we have the first deceased in the family, well my Philips ECG 6SN7WGTA I was keeping as placeholder on the dual triode slot, just to "light up" is dead. Well, we replaced it with a socket saver.



Not a big problem for me, I never liked this either, actually I guess it was the worse 6SN7 I've tried. I have somewhere another one, in one of the boxes, stored because I doubt I'll even listen to it. I might grab it to put it on the socket. I wonder if this feature of "all tubes light" where the one not selected by the input selector (single/double triode) has only the filament connected is somehow damaging something. I doubt, I guess it was just a tube which decided to die after some years. I doubt it had any damaging effect on the amp since the input selector was on single triode, for the Brimars. So I guess the filament died or hell knows. Maybe I'll shock the community by chosing there a GE tube, I have somewhere a GE 6SN7GT I am sure the guys will love. LOL

Based on the picture it seems that the top of of the tube turned milky white. If that is the case, the tube lost vacuum. Once the air enters, the silvery getter flash becomes white and that is the death of the tube. Could be a microscopic or larger crack somewhere in the glass envelope.

 

[OctavianH]

Based on the picture it seems that the top of of the tube turned milky white. If that is the case, the tube lost vacuum. Once the air enters, the silvery getter flash becomes white and that is the death of the tube. Could be a microscopic or larger crack somewhere in the glass envelope.

Yes, that was the case. I have no ideea why, the tube was sitting on my desk for a long time on some piece of paper. So no contact with anything or any kind of damage.

 

[triod750]

If there is an ever so slight leakage wouldn't this eventually happen when the getter is consumed?

 

[mordy]

Yes, that was the case. I have no ideea why, the tube was sitting on my desk for a long time on some piece of paper. So no contact with anything or any kind of damage.

In my personal experience it has happened without any known reason, but at other times the tube cracked somewhere from being dropped or knocked against another tube in storage.
Usually, when the tube dies the white death, it is instant but sometimes it can be more gradual.
I have noticed that Russian tubes are more resistant to breaking when dropped, compared to US made tubes.
-All part of the tube mystique!

 

[triod750]

I have noticed that Russian tubes are more resistant to breaking when dropped, compared to US made tubes.

I will challenge this. I will drop all my tubes and take notes. Did you ever compare to British made?

 

[mordy]

I will challenge this. I will drop all my tubes and take notes. Did you ever compare to British made?

I will challenge this. I will drop all my tubes and take notes. Did you ever compare to British made?

From my tube graveyard collection - there are many more...
Marconi KTZ61 - died of unknown causes
Russian 6N51P - the nib broke off while in storage - note white residue of getter flash
National Union 6J5GT - dropped on floor
Valvo EL12 - defective, some internal problem causing unbearable hum. Glass broken for educational purposes - note dual circular getters and heavy duty internals

 

[triod750]

I have now dropped fourteen tubes and none broke. My bed might have something to do with it but there could be some other explanation Experiments will continue...
I had a delivery by the post of one Chatham 6AS7G and one Mullard 6080. The box was intact and they were pretty well packed. The innards of the Chatham had shifted to the side, almost touching the glass, and the tube was dead. (Still kept its vacuum). The Mullard is working perfectly. 6080 is a robust design.

 

[mordy]

I have now dropped fourteen tubes and none broke. My bed might have something to do with it but there could be some other explanation Experiments will continue...
I had a delivery by the post of one Chatham 6AS7G and one Mullard 6080. The box was intact and they were pretty well packed. The innards of the Chatham had shifted to the side, almost touching the glass, and the tube was dead. (Still kept its vacuum). The Mullard is working perfectly. 6080 is a robust design.

During the good ol' days I bought three Chatham 6AS7G for not much money. During a photoshoot one rolled off my desk and broke. A second one gave up the ghost in use with no apparent cause. One left...
I assume that anyone using tubes for a while have similar experiences...

 

[OctavianH]

I was not able to remove for one week the GEC KT66 grey glass combined with Brimar 6SN7. This combo goes to my top 5.

I plan to make further comparisons of the KT66 clear vs grey glass but I need more time for that, most probably during winter holidays. I plan also to make further tests with EL156 which is an exceptional tube which was neglected by me due to lack of time. So I plan to put it into the lights again.

Other future plans? As always, something has to happen. Well, maybe some ECC40 or ECC808 on input and maybe some EL81, 4654K or EL39 on output.