[OctavianH]

@OctavianH to what i experienced you do not have a real Brand "Sound" but more a factory and a "technical" sound... By extension you have for tube before the 50's a bigger chance to have dedicated factory and building process only for one Brand. After all is more complicated starting in US and the same in Europe a bit after.
For Russian tube it is the same depending of some tube, some factory have a better building process and a more constant quality..

Yes, for me "house" sound is sound of the factory where it was manufactured. In the end Philips owned many factories in the 30s-40s in Europe and some of them produced the same tube with minor internal construction differences. Many of these tubes were branded as Philips - Made in Holland regardless of the factory and only the date codes are a clue about origin. Unfortunately, I do not know how to decypher old Philips codes from 30s. I have the newer codes but I also have many situations where codes are not matching the rules and format from the books. Mistery.

I also have some EL90 which I like in output. But I prefer 6/12AV6 or 6C4 in input...

The best EL90 I have found were manufactured in France and UK. If you can find some cheap SFR/Csf/Thomson EL90 you will be very pleased. Besides these the "black glass" UK made by Brimar (?) are also incredibly sounding. Digging more and more about french tubes I saw the P17 variants of 807/EL39 and honestly, I never thought there are so good looking and sounding tubes almost unknown to the majority. I put my SFR/CSF tubes at least at the same level as GEC/Mullard/Brimar.

And regarding 6C4 I was impressed lately by 9002. Works in the same adapters as 6C4 and my RCA 9002 sounded very good here, an idea more gain than 6C4 but good sound. Since nobody cares about 9002 you can find it very cheap, I found a quad in a box someone was selling "bulk" and asked him to put those 4 near my other tubes I was buying.

I need to hook the Odyssey to my Schitt preamp and see if that solves the problem. It’s hard for me, getting on the floor and back up can be an adventure. Hopefully I’ll have some news by the weekend.

I am really sorry about this. Too bad I live at the end of the world so I cannot help. I keep my fingers crossed. The best way I see is to try to isolate the problem by removing piece by piece and test each of them separately. Maybe indeed, the root cause was not in Odyssey.

 

[OctavianH]

I said today I'll do interesting things, so I have to do it now. Yesterday I prepared the outputs for my experiment: Philips 4689. Today I prepared the inputs. Something new, something loctal, something I have not read on these forums and I am happy about that. Here people fight the already lost war of famous tubes. No problem, I fight a different war.

So I made some preparations and this is my first loctal try after 7N7: EBL21. This is a double diode pentode, as EBL1, but successor and very close to metal base tubes construction. Now I guess you understand my preparations from yesterday.

These have different getters, some branded Philips made in Holland, others Mullard and so on. But in my "bulk" pack of 5 pieces all looking at first different (boxes and so on) I found a pair with L-code. So we have a nice pair with K78/L30 and K78/L3H. Even if date codes and revision is the close or the same, the glass shape is not perfectly identical. But inside all look identical:

I made some measurements, for input, for output, work fine both positions and I plan to use the same adapters to 6J5 also for output (should work, missing G2 on adapter but it's strapped in adapter and I measured there a 200 Ohm resistor, should be fine and keep screen current low). I am not very interested in output anyway, I have much better tubes for these. What I want is to have Philips metal base quality sound on input.

So I biased these at -8.2V for 180V/4mA and they are close around 1mA from each other. Not a problem for my 3-5mA range on input. All good to go.

Gain is around 20 on input, I would not go under this value because I think Eternity and my headphones sound optimal with higher gain tubes. This is why I am not very interested in too many pentodes in input. But if the gain is around 20, it's fine in my book. And if the sound quality is at metal base level, I am also happy. L-code are smooth tubes, I have some 4654K like those and like them a lot, so an excellent tube for input to smoothen a little bit the technical sound of the 4689 without loosing its excellent detail.

Some measurements:

In output I'll go around -6.3V for 200V/20mA:

I have some other construction types in the bunch, not pairs, I'll see what I can do with those. No hurry, I have enough tubes. My progress will be slower in the loctal chapter. I do not really need to invest too much because my focus is the old pentodes amp. But why not, if a tube is interesting and cheap I am here to help.

For example here we have a Tungsram rebranded Philips made in Holland:

The yellow printing of Tungsram is seen, H/7 date codes. Here is a 5-code EBL21, this one made in Holland with D-getter:

I have no idea if I'll really put these to output. But I'll definitely use them for input because they sound very good.

 

[OctavianH]

Classy looking. Nice glow.

And some remarks related to adapters: some of EBL1 or EBL21 have a small hum. Not problematic for me, but I guess the best way is to link D2/D1 anodes of the diodes to something, maybe cathode? Anyway, be warned that not all of these will be dead silent. But some are. In my case of this pair, the left channel has a very small hum hearable with volume set to 0. Right is dead silent. Left tube is branded Mullard - Foreign made and right is Philips Miniwatt. But L-code is MBLE in Bruxellses, Belgium.

My pair of RT EBL1 sounds leaner than the A-code WIRAG EL3N. Without having any proof, I think that the pair was also made in the "L" factory. Sounds closer to L-code EL34 or L-code 4654K. Of course, pure assumption but after many hours you start to recognize small nuances. This is why I am very reluctant to consider that one a Suresnes tube. In my case I prefer the RT EBL1 which I consider is made in the L factory to the A-code WIRAG EL3N because it's smoother and brighter, not so dry on mids. But of course, both are excellent. It's just my personal preference, and it was also half price of an EL3N. So well, you know, price has nothing to do with the tube itself but with the fame and demand of it.

PS. When I'll stop the amp I'll switch the adapters so I'll check if the hum is related to the tube itself or the adapter. Or maybe both or something related to the circuitry of the amp. I observed that some adapters/tubes are noisy at very high gain but this is not the case.

Later edit: The small hum in one of the channel moved from left to right when I switched tubes, leaving adapters in position. But on right channel is even less. So it's a tube problem, solved 50% now by switching. The misterious ways of tubes.

 

[OctavianH]

And another intersting thing, on Ebay there are several Tesla/Telam EBL21 like for example here. I have a Haltron branded which seems the same:

Polam/Telam tubes are interesting, and it seems besides EL84 many praise they made also EBL21. Tesla 4654 is a very good tube, so Tesla/Telam have potential. Of course on that listing the price is wrong, but you can search more.

 

[LobalWarming]

And regarding 6C4 I was impressed lately by 9002. Works in the same adapters as 6C4 and my RCA 9002 sounded very good here, an idea more gain than 6C4 but good sound. Since nobody cares about 9002 you can find it very cheap, I found a quad in a box someone was selling "bulk" and asked him to put those 4 near my other tubes I was buying.

Nobody cares... but somebody has been reading your posts and priced them accordingly.

 

[OctavianH]

Nobody cares... but somebody has been reading your posts and priced them accordingly.

Ah ok, ignore this guy. Here:

 

[hpamdr]

As usual, haltron is the lottery... I got some Haltron 6N7GT in the past from o UK dealer and half of it are really great and the other ones are like RCA or GE tubes
About Diode pentode like 6AV6, i did first adapters without wiring the diode pin and the latest ones with dedicated wiring

And another intersting thing, on Ebay there are several Tesla/Telam EBL21 like for example here. I have a Haltron branded which seems the same:



Polam/Telam tubes are interesting, and it seems besides EL84 many praise they made also EBL21. Tesla 4654 is a very good tube, so Tesla/Telam have potential. Of course on that listing the price is wrong, but you can search more.

As you probably know, haltron is much a rebrand company made for spare part I got mullard, phillips, rca and even russian tube for the same item :~
We have the same in France Neotron basically selling mazda, RT, visseaux... It also captured local army huge contract for air or navy with a lot of selection constraints. I never found a crappy tube from NEOTRON which is not the case with (feel lucky) Haltron...

I've been to a jazz listening and wine, cognac and cigars session with friends... I should not have done it I've rediscovered quad ESL63 listening capabilities with a STAX earspeaker SR-L700 or better SR-007.... New dilemma those "EarSpeaker" does not work with our lovely Eternity without new materials or new amps
At the place we had a BlueHaway for ElectroStatic, octave V16 for dynamic
dcs Streamer and DAC (Rossini APEX).
What i'm still sure is that i do not like hifiman stuff. (except the electrostatic one but i'm not finding night and day difference with the x9000 ). It is like for climate, the consensus is for the adviser and the sellers....
We testes ~10 pairs of headphones:
STAX SR L700, 007 MKII, new x9000.
heedPhone 2,
ERZETICH Charybdis,
Hifiman HE1000 se, Susvara, Shangri-La Sr.
Focal Utopia,
Fostex TH909...

I was pleased a lot by the STAXs, the Charybdis, I knew the heephone, the focal and the fostex !
As my price point is not more than 3K those are the one in bold.

(To not take my choice as an advise) I'm getting old so probably missing some hightssss, and do not like hard ticking bass. I do not listen loud, really not !
I was many years ago when doing my phd and travelling for HardRock concert with some friends, ancient music with others and jazz and french pop with mixed and specially the one with opposite gender )
(This was also my surprise at this event that younger folk listen and note as a quality HP able to play LOUD i note as a quality ability to play at very reduced volume)

 

[OctavianH]

As usual, haltron is the lottery... I got some Haltron 6N7GT in the past from o UK dealer and half of it are really great and the other ones are like RCA or GE tubes

I have some "Haltron" EL90 which are RCA.

About Diode pentode like 6AV6, i did first adapters without wiring the diode pin and the latest ones with dedicated wiring

D2 and D1 linked to Cathode? Any differences?

heedPhone 2,

How do you find HEDDphone TWO? I bought it and returned it. For me it lacked any kind of enjoyment, subbass roll-off, highs rolled-off and so on. Too technical, like the sound of the production desk not a headphone to listen to music.

ERZETICH Charybdis,

How is this one? Comfort? Sound? Looks heavy.

I was looking at Austrian Audio The Composer lately but for me looks like an overpriced AKG. Anyway, AKG made good headphones during the years.

Regarding tubes, sometimes they are indeed a lottery. For example, I have 2 pairs of identical Philips 4689. One is older and one is newer (one pair 52/FE5 and another 51/FE5). Same construction, same tube type, close date codes. My newer pair sounds better than the older pair. You would say, the older the better but well, the older pair sounds an idea harsher and maybe with an idea less bass. I let both of them burn in for hours, compared from time to time, difference is audible. In the end put the older pair to storage. Why? Maybe I need to clean pins of the older pair, but I was never convinced that pin cleaning has audible difference as long as contact is properly made. Others say it has. Another option would be to replace solder but it's an idea above my skills. So even 2 pairs of identical tubes are not sounding the same or might be better or worse. What to say about rebrands or different construction in several tubes of the same type.

 

[hpamdr]

How do you find HEDDphone TWO?

I have HEDDPhone I and i like it a lot. It is very transparent and probably too neutral to your taste (Take it as a studio headphone). I personally did not listened the heddphone 2, people said it is more comfortable than the 1st version but same sound signature with a darker presentation... I use the 1st in bed or in sofa so comfort is not an issue anymore once you get the band adapted to your head (mine is XS).

ERZETICH Charybdis,

How is this one? Comfort? Sound? Looks heavy.

This is not lightweight at all but the band is well designed, the pads are really soft it is globally comfortable. It is really a nice sounding, very fast and precise the gigantic 110mm makes the music well presented and really magic wit soft pop an smooth jazz. I would not buy one as 740g is even 20 more than the HP 1. I would not recommend it unless you are ready to do listening on a stressless or himolla relaxation chair.... I'm pretty sure th showroom effect will be present specially if you just listen to to for 30 minutes...

 

[OctavianH]

Philips 4689 with Telefunken ECC801S. A very technical presentation. Detailed, fast, focused. I guess this is one of the most analytical combos. Besides this one, the Philips 4654K with ITT Lorenz E88CC was maybe on the same level. A demonstration of technicality to prove all the SS guys that a tube amp can sound technical.

In my case, while I really like what I hear, I miss my EL50 and the old pentodes. Those have more life in them while keeping a decent technical level.

 

[OctavianH]

But why loose a nice weekend evening listening to your equipment instead of listening to music? No reason. So I went again to my old pentodes and this time tried Adzam EL6 with Philips EL3N (WIRAG). Another level. Honestly. But my latest experiments with USB cables and HQ Player made me realize my system is favouring this type of sound with all those silver cables. On a differently tuned line or a different headphone amplifier maybe the more technical combos will prevail. All is a matter of synergy.

In my case I do not feel any loss of dynamics or detail while switching to this combo. But all becomes more organic and natural. A very punchy and lively sound. Of course, not at the same level of the 4654/EL50 because that sounds bigger and all goes wider and more equilibrated. Here I feel I am a little bit on the highway and this is because of the EL6 which has higher gain.

And now I can focus on discussing with the monk, the sound is exactly as it has to be: alive.

 

[triod750]

i note as a quality ability to play at very reduced volume

This I am in agreement with. Also important feature with loudspeakers. I find that I listen deeper into the music in a more relaxed way at a lower sound level.

 

[hpamdr]

This is one of the bier i like the most when i go in germany This is also the best place to go fast on authobahn
The Full EL3N / 6M6 remain me F.A. Euphoria ages.

 

[OctavianH]

This is one of the bier i like the most when i go in germany This is also the best place to go fast on authobahn
The Full EL3N / 6M6 remain me F.A. Euphoria ages.

Dark unfiltered beer is good, but I avoid to combine it with Jever or Warsteiner, for example. In the latest years beside the "classics" I've enjoyed a lot several types of IPA. Of course, like audio, beer industry is going into the wrong direction inovating for people who do not really like beer, so they invented beer with fruits, sour beer and other kinds of abominations. Whenever I go to a craft beer pub I have to first search for all of these to ignore and then find 4-5 types which make sense to try.

 

[hpamdr]

As I'm currently getting most of my bier from a local brewery. The guy is an organic Farmer makes his own malt from the barley growing in his farm.
He is selling once a week direct from the mini/micro-brewery, He is passionate and wanted to start hop cultivation, unfortunetally Covid and Ukraine made the project too hard to finance...
Side to this, i will try to find some time to start building socket with cap plug for Anode and Grid (I will be able to use vr135 and other stufff)