Author Topic: What Make Valve?  (Read 4789 times)

Offline Schalk

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Re: What Make Valve?
« Reply #15 on: July 11, 2016, 08:59:08 PM »
Do not go blaming the monos if clicking/popping/hissing and protection frights damage those panels...  :nono:

Also had another customer who bought from the same supplier (Down in the Cape area I think !) 5 of those. One also had thinner pins and the gold also chafed off of the pins in places like they had been used before? Your photo seems to confirm this "used" state. The differing pin thicknesses would suggest they do NOT in fact make their own tubes like they promote in their sales blurb, but pick from the crop available and then "do their magic wand thing" .


Offline Ampdog

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Re: What Make Valve?
« Reply #16 on: July 12, 2016, 03:56:28 AM »
The tube withstands accelerations of 2,5 g at 50Hz for lengthy periods and momentary shocks of 500g for short periods.) I would like to know what the sound pressure would be at 50hz to produce 2.5g of shock. Snake oil?

Not necessarily snake oil.  But this spec is often misunderstood; it has nothing to do with sound waves 'impinging' on valves. It refers to rough handling, in equipment such as heavy machinery or military equipment (I was not joking before re army tanks!).  It was relevant in the days of mainly valve equipment; these days one can hardly imagine such applications not to be served by solid state devices. In that sense I intimated that such specs are of little relevance in audio; specs regarding mechanical stresses referred to the above applications. Specs regarding valve life and operating conditions for 'special valves' will also apply to audio and are of value mainly for use in bands, guitar applications and the like, i.e. daily use and perhaps manhandling in transport from A to B.

Relevant to valve specs Philips states for their valve tests:

"Shock:  The tube is subjected 5 times in each of 4 positions to an acceleration of 500g supplied by an NRL shock machine with the hammer lifted over an angle of 30.

"Vibration:  The tube is subjected during 32 hours in each of 3 positions to a vibration frequency of 50 Hz with an acceleration of 2,5g."

(Note: NRL = National Research Laboratory;  g = gravitation force: 9,8062 dynes)

Triton,

Firstly, respectfully,  not suggesting that anybody buying these valves was a fool! All of us get mislead despite careful research into claims. Sadly, that is what keeps certain brands/devices selling.

Now that you are where you are, pity it can perhaps not be possible to 'slide' off the surrounding metal tube to investigate what actual brand of valve is underneath. (You may void any guarantee still in existance.) As Schalk said, one of the many things to be checked if one can is the so-called gold plating or other marks on pins. Even in proper products gold plating does not mean a lot. This can be 'scored' or damaged during the first couple of pluggings in and out.

You have my sympathy, and I hope you can make life difficult for the relevant sales people/manufacturer. You have paid dearly (well, hopefully you can get back some of your money); I hope the rest of us learns from your misfortune.

Regarding valve pins: Jeepers! I vaguely recall a similar experience with octal valve base pins but certainly once only. Can you perhaps check the two diameters with a suitable tool and warn us? (Normal miniature valve pins I have as 1,0 mm. I could not find the tolerance on this at this time.)

Apology that this went somewhat OT. But information like this is mandatory to the valve community.
What a world ....


P.S. later:  I will mention this experience on the large audio forums where I am a member.  The "audio heavies" on there can make life difficult for manufacturers when necessary.   
« Last Edit: July 12, 2016, 04:09:32 AM by Ampdog »
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Offline Triton

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Re: What Make Valve?
« Reply #17 on: July 12, 2016, 07:28:39 AM »
Hi Schalk

Haha i would never dream of blaming the monos, ive blown up a few speakers and every time been amateur mistakes..i just got a massive skrik when the protection kicked in and felt like jumping on those valves!!

Ampdog

Not a problem, getting the correct information is what's needed..
I tried to slide off the metal part but pretty sure it's glued on there, was sure im going to crack the glass if i pushed it any harder.
Would have liked to put a vernier on those pins to see what the difference is, just out of country at the moment. Im sure they would not have been replaced by the time im back so will have a look then.
The supplier actually told me he can crimp my valve sockets so the valve would sit snugly? Yeah good luck with that. That's beyond the point that i have 2 different valves!

Will see what happens in the next week or so before i start sending them mails naming and shaming them.

Offline ScottulusMaximus

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Re: What Make Valve?
« Reply #18 on: July 12, 2016, 08:51:28 AM »
Oh deary me, R5k for 2 random valves with a bit of aluminium stuck over them...

I must say it's a smart business(read: scam), shoddy execution if they couldn't match pins though. All they needed to do was buy JJ's and no-one would've noticed.
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Online charles

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Re: What Make Valve?
« Reply #19 on: July 12, 2016, 08:53:05 AM »
Some correction please:

6922 is not the same as ECC88


6922 direct equivalent is E88CC
and
6DJ8 direct equivalent is ECC88
Source: Telefunken Taschenbuch 1963 Rohren und Halbleiter

I may be possible to use an ECC88 in place of an E88CC under certain instances.



Offline Ampdog

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Re: What Make Valve?
« Reply #20 on: July 13, 2016, 12:18:12 AM »
...... Which makes me wonder about valves testing better than 100% ( people state 120/130/140% on Fleabay ) . Is the valve not out of spec then ? ( if tested as , say , 130 % )

This was overlooked 'in all this excitement' (as Dirty Harry told the baddy just before he blew his head apart):

True.

Folks unfamiliar with valves (or transistors for that matter) seem to think that >100% is an improvement. Apart from showing up perhaps gas, it simply becomes a different valve, which may or may not work in a particular application. Operating conditions (voltage, current, grid bias) might not be suitable, and in extreme cases lead to non-operation or destruction of something. (One might as well claim that a transformer tested 'better than 100%' and is therefore fine, if the 6,3V heater voltage measures 7,3V!).
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Offline Triton

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Re: What Make Valve?
« Reply #21 on: July 13, 2016, 11:03:43 AM »
Just as a matter of interest and being new to valves.. 6H30pi valves.. are there only Sovtek and Electro Harmonics available in these? Have not been able to find anything different..

Thanks

Offline Kent Kassler

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Re: What Make Valve?
« Reply #22 on: July 29, 2016, 08:35:05 AM »
Hi Ampdog

The fact that they advertise the valves  - ( The tube withstands accelerations of 2,5 g at 50Hz for lengthy periods and momentary shocks of 500g for short periods.) I would like to know what the sound pressure would be at 50hz to produce 2.5g of shock. Snake oil?
Ok so being the sucker and skeptic that i am i bought 2 of the EAT cool valves Diamond 6922. Once i got them it did not start off so well. One of the valves had thinner pins than the other and seemed like a softer copper. This caused hissing and popping and thrown the amp into protection mode.. Mailed EAT direct and asked about this as they have such high standards as advertised. They just came back with asking for a proof of purchase and from which country. 3 mails later (not hearing back from them) i contacted the dealer and asked for a replacement. That's 2 weeks ago, the dealer still waiting to hear from the EAT team about the replacement. You would think to dish out 5k for 2 valves the service would be better...
In the mean time i also bought 2 Telefunken 6922 NOS tubes at about a 1/4 of the price of the EAT valves..
Going to be interesting to put them up against each other...that is if i get a replacement EAT valve.


Wow!.....more snakeoil bullshiit floods Audiophilia. ...hide the mediocrity in glued on heatsink and away we go.....unbelievable and yet so real.....who may I ask sells these gems here in the Cape Triton?
Audiophile Sound Sommelier Extraordinaire....aka Manic Depressive Temporary Void Filler Deluxe.

Offline Triton

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Re: What Make Valve?
« Reply #23 on: July 29, 2016, 11:09:08 AM »
Hi Kent

Just google - eat cool valve ecc88 in South Africa and the dealers name will pop up. Don't want to go name and shame as yet..even though i want to as he pulled a Houdini on me not answered any of the 10+ emails sent..

I finally got a response from EAT

They said the dealer has not bought from them in a long time so the tubes will be out of warranty anyway. 6 months as advertised by EAT.
They will however offer me new tubes at a discounted price... :nutter: