Test Equipment Anonymous (TEA) group therapy thread

[med6753]

My understanding is that valves sound better because the 2nd harmonic distortion sounds better.

No, I do not understand audiophools' reasoning.

That is true. Vacuum tubes generate even order harmonics which supposedly sound "smooth". Transistors generate odd order harmonics which supposedly sound "harsh".

But I truly believe you need the hearing of Fido in order to tell the difference but many phools claim they can.   

[Ice-Tea]

Double blind or it didn't happen 

[med6753]

Double blind or it didn't happen 

No argument from me. 

[BU508A]

...
Back then, we found that, during those years, in terms of reliability & meeting initial specs, the list read:-

AWV-----consistently exceeded specs
RCA-----consistently met specs
Siemens------consistently met specs
Sylvania------consistently met specs
GE------usually met specs
Philips------usually met specs
Mullard------usually met specs, with some "really battling"
Brimar,------usually met specs (just)

with the others making up a gaggle of "also rans">

Missed TFK (Telefunken)
and for good old TEA stuff you go for E8*CC   (12A*7WA)

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring! 
https://www.ebay.de/itm/125039613957

[Neper]

Missed also Valvo tubes.

Wasn't that Philips?

[med6753]

...
Back then, we found that, during those years, in terms of reliability & meeting initial specs, the list read:-

AWV-----consistently exceeded specs
RCA-----consistently met specs
Siemens------consistently met specs
Sylvania------consistently met specs
GE------usually met specs
Philips------usually met specs
Mullard------usually met specs, with some "really battling"
Brimar,------usually met specs (just)

with the others making up a gaggle of "also rans">

Missed TFK (Telefunken)
and for good old TEA stuff you go for E8*CC   (12A*7WA)

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring! 
https://www.ebay.de/itm/125039613957

Please, I still have an arse ache for paying $50 USD for a single Ampex gold plated pin 8416 tube. 

[vk6zgo]

Now, if the valve met its specifications when put on the tester, initially, was there sound or performance issues between the brands?

Because, what is claimed by the 'phools and their brethren "some musicians" is that some brands (usually not from the top of your list!) consistently sound "more magic".  It is not about being so scientific so as to select valves by tested performance. That's too cold, and unsympathetic...

We did find that the Marconi video circuitry worked measurably better with tubes which "exceeded specs", & the ones which were "marginal" caused linearity errors more rapidly as they aged.
The "good" ones had greater "headroom", & took a lot longer before this became a problem.

In my opinion, not giving enough margin for device parameter changes was a failure on the part of Marconi's designers.

The Marconi equipment seemed to be critically designed for "better than spec" devices, whereas the Fernseh PGM75 video generator, of a similar generation, using similar tube types, could still produce excellent signals, even with tubes which became "below spec" over time.

[BU508A]

Missed also Valvo tubes.

Wasn't that Philips?

They belonged to the Philips Konzern but I had always the impression, that Valvo acted independently.

https://de.wikipedia.org/wiki/Valvo

"1927 schlossen sich C. H. F. Müller und die Radioröhrenfabrik dem Philips-Konzern an. Schon in den 1930er Jahren erweiterte man das Fertigungsprogramm um weitere Bauelemente, um Bildröhren, Elektrolytkondensatoren, Lautsprecher, Hochohmwiderstände und Spezialröhren"

Translation via DeepL:
"In 1927, C. H. F. Müller and the radio tube factory joined the Philips Group. As early as the 1930s, the production programme was expanded to include further components, picture tubes, electrolytic capacitors, loudspeakers, high-impedance resistors and special tubes."

[vk6zgo]

...
Back then, we found that, during those years, in terms of reliability & meeting initial specs, the list read:-

AWV-----consistently exceeded specs
RCA-----consistently met specs
Siemens------consistently met specs
Sylvania------consistently met specs
GE------usually met specs
Philips------usually met specs
Mullard------usually met specs, with some "really battling"
Brimar,------usually met specs (just)

with the others making up a gaggle of "also rans">

Missed TFK (Telefunken)
and for good old TEA stuff you go for E8*CC   (12A*7WA)

We got a few Telefunken ---they had a "tie up" with AWV, as did RCA, so if the local company was at the wrong end of a production run, they would be substituted.
Telefunken would be in the "consistently met specs " group.

[McBryce]

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring! 
https://www.ebay.de/itm/125039613957

I wonder what effect the 45° Getter has on the vibrance, transperency and sound stage when used by an Audiophool? 

McBryce.

[med6753]

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring! 
https://www.ebay.de/itm/125039613957

I wonder what effect the 45° Getter has on the vibrance, transperency and sound stage when used by an Audiophool? 

McBryce.

The sound emanates at a 45 degree angle from the speakers. 

[0culus]

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring! 
https://www.ebay.de/itm/125039613957

I wonder what effect the 45° Getter has on the vibrance, transperency and sound stage when used by an Audiophool? 

McBryce.

The sound emanates at a 45 degree angle from the speakers. 

Clearly, the getter rings are helping with high frequency sounds. 

[mnementh]

My understanding is that valves sound better because the 2nd harmonic distortion sounds better.

No, I do not understand audiophools' reasoning.

That is true. Vacuum tubes generate even order harmonics which supposedly sound "smooth". Transistors generate odd order harmonics which supposedly sound "harsh".

But I truly believe you need the hearing of Fido in order to tell the difference but many phools claim they can.

[SOAPBOX MODE]   

Sorry... musicians can tell the difference; so there has to be something. As it is generally their preference upon which the source material is built, I'm sure that some... ahem... critical listeners can tell the difference, just as you and I can tell the difference between a square wave and a sine wave played through a loudspeaker.

Consider this: the tinkerdwagon's big snout isn't all for show; I (and my son) were blessed with unusual olfactory acuity for human beings. As in, I used to be able to track animals by scent, and I knew my farm animals from those belonging to other farms. Flop sweat (even minute, invisible amounts) is particularly acrid, and it makes my hackles rise when I smell it, as I know someone is peddling bullshit in my vicinity. Also "grrl fumes" (as I refer to that group of pheromones that a strong-willed female emanates)... *si-i-i-igh* ...they literally make me feel euphoric.

Point being... some people have an unusual acuity in one or more senses; it alters your entire outlook on reality, and how you interact with the world around you. And for me, part of that is teaching my son how to use that olfactory acuity to give him an edge dealing with the world, and how not to be a slave to it, as many are.

We have no problem accepting that a sniper has exceptional visual acuity, or that a surgeon has exceptional sense of touch/dexterity; yet somehow the notion that someone can hear exceptionally well and can hear things we cannot seems to be something we hold a particular prejudice against, the same way stupid people take offense at being called stupid. 

Now yes, I get that some of the audio-phoolery we loathe is just wishing they had hearing acuity similar to that of the people who made the music they love, combined with a certain amount of confirmation bias. For we who are all about measurable, quantifiable signal quality, much if not all of the "awesome sauce" bandied about in these circles does seem like yet another aspect of the usual "My, what a gullible breed..." syndrome.

But arguing that one particular brand of tube cannot have a different "sound" from another, when they are actually physically constructed differently because each company's engineers had a different vision for how best to make a particular classification of valve... I can't say I agree with that.

Just because the diagram for how they're constructed looks the same does not mean they function exactly the same; things like exact spacing/shape of the elements of the tube have to affect how it amplifies/mixes/distorts the sound, for the same reason we have thousands of different types of silicon transistors, each one optimized for a certain purpose, yet they all have the same symbol.

Honestly, between the shameless vitriolic loathing of everything we can shove in the "audiophoolery" pigeonhole, and the way we seem to feel that our use for tubes is the only important one, we tend to be pretty fucking judgemental and even prejudiced in here.

Of course it makes me cringe when I see/hear of someone trashing a perfectly good (or even marginally good in need of TLC) hollow-state scope or counter, etc just to get to those big-$$$ choobs... but it is the trashing of the device I loathe, not the harvesting of valves. As far as I'm concerned, if someone pulls the tubes out of such a device carefully and non-destructively, that is in and of itself showing the respect it is due, and those tubes are a consumable supply anyways.

We who enjoy hollow-state need to separate "but the choob-vultures made fixing this particular one so fucking expensive" aggravation from that where actual sins are committed in the acquisition of said choobs.

If the only real gripe we can honestly lay at someone's feet is that their hobby makes our hobby more expensive, then we are ourselves guilty of some pretty severe prejudice, compounded with the very blend of confirmation bias and Dunning-Kruger we habitually accuse the audiophools of; only it is literally the inverse function, the flip side of that same coin.

[/SOAPBOX MODE]

mnem
We knew that this was a expensive hobby when we got into it. Hating others for that fact is just dumb.

[mnementh]

Missed also Valvo tubes.

Insane example for an ECC83 from Valvo with a 45° declined getter ring!        https://www.ebay.de/itm/125039613957

I wonder what effect the 45° Getter has on the vibrance, transperency and sound stage when used by an Audiophool? 

McBryce.

The sound emanates at a 45 degree angle from the speakers. 

Clearly, the getter rings are helping with high frequency sounds. 

I think that maybe this plays into my rant above a wee bit; I'm pretty sure the design of the getter ring is more a matter of identifying a particular design of this specification of valve (particularly for non-engineer types) known to have a particular "sound" rather than any specific function it actually has in circuit.

OTOH, perhaps it actually alters the capacitance of the valve's circuit as a whole, causing a mixing/delay/acceleration of electron flow some find pleasing...? 

Sadly, much of the "art" of valve design is lost to the mists of time; I expect there was a whole world of very special knowledge about how certain designs for the material the elements were made of, the kinds of mesh used, the shape, and spacing, etc affected a particular tube's performance that used to be common knowledge among such engineers, just as today there is similar very special knowledge about how the silicon dies are formed and doped in the manufacture of transistors.

You can only put so much in the  technical reference books. 

There had to be reasons for the way different manufacturers designed certain specifications of tube. Yes, I'm sure that a lot of it revolved around the simple mechanics of that manufacture, but there also had to be a reason Tek stuck with specific brand/spec of tube for specific purposes over many years of production, too.



mnem
Maybe they just liked the way the scope "sounded" better with them.

[0culus]

My gripe with audiophools is pretty simple: they use up the fixed supply of quality NOS tubes while driving up the prices to insane levels for 100% subjective "soundstage" or whatever other BS they come up with. Or, even worse, they rape perfectly good equipment of tubes. I know for a fact that some tube vultures straight up stole a bunch of tubes right out of scopes when they sold Stan Griffiths' collection. They opened scopes, removed the good tubes, pocketed them, and walked out without paying.

In any case, these are the same people who will happily drop $10,000 on a fucking power cord because they think that the short run from the outlet to the power supply is going to make any difference at all.

It's possible to be an audiophile without being an audiophool. I know one. But sometimes a duck is a duck, and an audiophool is an audiophool.

[BU508A]

My approach is even simpler:
If you can measure a difference, then there is a difference.
If you don't measure it, then there is none.

But you have to do proper measuring, of course.

All other things I'll call bullshit, no matter what.

[mnementh]

Yes, but what do you measure for...? If you don't believe the difference exists, you aren't going to know how to set up your testing scenario.

How do you measure for the "warmth" of the sound, when that really is just a subjective description for how a particular tube distorts the signal going through it, which some people (usually musicians) prefer?

How do you measure for what is just the right amount of "fuzz" distortion or gated reverb, when that is entirely subjective, and dependent upon the artist's ear, which probably has suffered massive damage due to close proximity to the stacks for a decade or three?

I'm sure that folks who work in the trade... for example, those who worked with Phil Collins... can explain things like gated reverb and how to "get his sound", and could even identify it by sight from the trace on the screen of their favorite post-processing studio... but that is not the same as being able to objectively test for it.

Art is art and science is science... everything we as human beings do that is of import combines the two, and both are essential. FULL STOP.

mnem
 

[mnementh]

My gripe with audiophools is pretty simple: they use up the fixed supply of quality NOS tubes while driving up the prices to insane levels for 100% subjective "soundstage" or whatever other BS they come up with. Or, even worse, they rape perfectly good equipment of tubes. I know for a fact that some tube vultures straight up stole a bunch of tubes right out of scopes when they sold Stan Griffiths' collection. They opened scopes, removed the good tubes, pocketed them, and walked out without paying.

In any case, these are the same people who will happily drop $10,000 on a fucking power cord because they think that the short run from the outlet to the power supply is going to make any difference at all.

It's possible to be an audiophile without being an audiophool. I know one. But sometimes a duck is a duck, and an audiophool is an audiophool.

Yeah, that all boils down to bitching that your hobby is expensive and looking for a scapegoat. Sorry, we all knew this was a expensive hobby when we got into it.

mnem
 

[BU508A]

I don't care about "warmth" or other adjectives being used by audiophools, because there is NO definition, what "warmth" means in terms of quantity.

Therefore: bullshit.

This kind of reasoning leads directly to esotericism, homeopathy, astrology, audiophoolery etc., or, in other words: bullshit.

EOD

[factory]

502A :
Also, another thing that makes the front panel look good, to me at least, is that the UHF connector don't have the usual crusty semi-transparent, vomit brown dielectric piece in them. All my scopes do... not this one. Somehow the dielectric piece still looks brand new, sparkling, snow white. Weird. The outer / threaded part still looks old an crusty, but the dielectric piece no, it's like new.  Maybe Tek had different suppliers for these UHF connectors... or maybe the 502A having out of the ordinary specs compared to the general purpose models, called for different UHF connectors specs ? Don't think so... as my other 502A has the ugly brown dielectric, not the white one...

Looking at both mine & your other 502A with the "ugly brown dielectric" UHF connectors, they are both US made.
The one you just acquired is Dutch made, possibly they sourced those UHF connectors locally and they happened to have the white dielectric.

I don't know, mine did have a sweep, I can't remember if that was before or after sorting the broken intensity control, it also had three white toobs, one of which was the neon voltage reference. It was rescued from a local house clearers stall at a vintage agricultural steam/yesteryear show for £20.


This diode failed twice on the Timebase mode switch (looking at the picture now probably needs the neon replacing too), then this transistor was found deceased (maybe due to open circuit neon indicator causing over-voltage), it's currently in storage.


David

Thanks for that  ! 

And also thanks for rescuing this puppy ! For 20 quid sure was worth it ! Looks a bit rough on the outside but the inside is quite clean... the contacts in the wafer switches look SO much better/shinier than mine here ! They are 100% black, horrible ! 

Yeah it looked terrible from the outside, didn't help that it also had got rained on in the morning at the show, I couldn't go till the afternoon if I remember correctly. I guess the seller was happy to not have to take it back with him, not so much fun was carrying it all the way to the car park field.

It was quite grubby on the inside too, the trigger circuitry is much cleaner, due to the being directly under the top covers.

The only vacuum tubes that drive me nuts are nuvistors. If they have been dormant for many years they take a long time to "wake up". Seems they require many hours of burn-in to de-gas themselves and become stable. But since that Type 502A is low B/W I doubt it has any nuvistors in it.   

You probably want to avoid 502A s/n 025997 to 030999, apparently they have a pair of nuvistors and many tr*ns*st*rs on each front end PCB. I can't spot where the nuvistor is in the pictures though. Edit: found them in the 025997 to 030999 vertical amp picture.
https://w140.com/tekwiki/wiki/502

David

[mnementh]

I don't care about "warmth" or other adjectives being used by audiophools, because there is NO definition, what "warmth" means in terms of quantity.

Therefore: bullshit.

This kind of reasoning leads directly to esotericism, homeopathy, astrology, audiophoolery etc., or, in other words: bullshit.

EOD

*yawwwn*

Yeah, that is a horribly narrow-minded POV. Good thing we also have artists who actually know better, or there'd be nothing in the music world except robot-performed instances of Wagner, every recording of which sounded exactly the same.

mnem
 

[0culus]

My gripe with audiophools is pretty simple: they use up the fixed supply of quality NOS tubes while driving up the prices to insane levels for 100% subjective "soundstage" or whatever other BS they come up with. Or, even worse, they rape perfectly good equipment of tubes. I know for a fact that some tube vultures straight up stole a bunch of tubes right out of scopes when they sold Stan Griffiths' collection. They opened scopes, removed the good tubes, pocketed them, and walked out without paying.

In any case, these are the same people who will happily drop $10,000 on a fucking power cord because they think that the short run from the outlet to the power supply is going to make any difference at all.

It's possible to be an audiophile without being an audiophool. I know one. But sometimes a duck is a duck, and an audiophool is an audiophool.

Yeah, that is just bitching that your hobby is expensive and looking for a scapegoat. Sorry, we all knew this was a expensive hobby when we got into it.

mnem
 

No it fucking isn't. I can go down to my local surplus store that stocks tubes and I can buy a whole box full of TV and radio types for the same price as one 6DJ8 dual triode. Not that it does me any good for repairing test equipment, but there's a reason all those are pennies on the dollar and 6DJ8s are expensive. BECAUSE THE AUDIOPHOOLS THINK 6DJ8s ARE SPECIAL.

[mnementh]

For them it is. They're willing to pay for it; supply and demand, wahh, wahhh, wahhh...

Seriously, you're just doubling down on the same argument, not making it better.

mnem
*agitating-ily*

[BU508A]

I don't care about "warmth" or other adjectives being used by audiophools, because there is NO definition, what "warmth" means in terms of quantity.

Therefore: bullshit.

This kind of reasoning leads directly to esotericism, homeopathy, astrology, audiophoolery etc., or, in other words: bullshit.

EOD

*yawwwn*

Yeah, that is a horribly narrow-minded POV. Good thing we also have artists who actually know better, or there'd be nothing in the music world except robot-performed instances of Wagner, every recording of which sounded exactly the same.

mnem
 

Nope, your POV is narrow-minded. Art is art, that's what it is. There is no art in claming things, which aren't there.
Today, we are able to measure things several order of magnitudes better than the best human ear can hear.
If signals are identical by measuring them and still claiming, there is a difference, is a complete ignorance in respect to science.
And THIS is narrow-minded, because science ALWAYS wins.

[med6753]

You probably want to avoid 502A s/n 025997 & above, apparently they have a pair of nuvistors and many tr*ns*st*rs on the front end PCBs. I can't spot where the nuvistor is in the pictures though.
https://w140.com/tekwiki/wiki/502

David

Well, if I ever do come across a high S/N Type 502A with nuvistors I'll accept my fate and burn them in to hell and back until they stabilize.