Old valves worth collecting ?

[Jolly 7]

I am not in to valve radios but was wondering about these valves I purchased abroad cheaply purely out of interest. One is a Tungsram EF86 and the other a Siemens EC92. Would these be of much interest to valve radio enthusiasts ?

Hello, unfortunately they are quiete common noval valves, about 5-15 euros each one

[Aub]

The EF86 might be attractive to audio enthusiasts, depending on where it was made, etc.

Cheers

Aub

[ColinTheAmpMan1]

I would venture that if they are new (and they look to be so), they are not really Tungsram and Siemens, as I think those manufacturers became defunct ages ago. They will likely be manufactured somewhere in the East (Russia, China?) and branded as Tungsram and Siemens. I could be wrong, though....
Colin.

[Sideband]

The EC92 was not used much in UK sets. I think it's a VHF triode. Nothing special and there are lots about.....sorry! The EF86 you have looks like an import....Miniwatt was used by Philips. Dario is a brand I have seen and I think it's German. The EF86 in itself is nothing special...just a low noise AF pentode. A genuine new Mullard one might attract a few extra £ but again....lots about.

[bikerhifinut]

the EF86 is a Miniwatt Dario which afaik was one of philips brands? it's not Tungsram.
Could have been made anywhere especially towards the end of production, but it has the look of a western european one.
Worth the same as any other I'm afraid. There isn't yet a shortage of EF86. ooops crossed with sideband

[Jolly 7]

The EF86 has no country of manufacture anywhere but the EC92 does say Made in Germany and 222 written on it. Not sure what the latter means but thanks for all the useful responses.

[Paul JD]

The EF86 appears to be a Dario Miniwatt, these were made by Phillips in Holland. Watford Valves are currently selling NOS ones for £34 + VAT

[Jolly 7]

Originally Posted by bikerhifinut

the EF86 is a Miniwatt Dario which afaik was one of philips brands? it's not Tungsram.
Could have been made anywhere especially towards the end of production, but it has the look of a western european one.
Worth the same as any other I'm afraid. There isn't yet a shortage of EF86. ooops crossed with sideband

It's quite possible the Tungsram box belongs to a completely different valve. The seller had no idea what he was selling and I didn't expect too much anyway as it was right in the middle of a fish and vegetable market

[Cobaltblue]

Originally Posted by ColinTheAmpMan1

I would venture that if they are new (and they look to be so), they are not really Tungsram and Siemens, as I think those manufacturers became defunct ages ago.
Colin.

Although Siemens stopped making valves a while ago they are not defunct with a turnover of 84 billion euros and 372,000 employees I doubt they would be interested in putting their name on a few dodgy valves

https://en.m.wikipedia.org/wiki/Siemens

You never know though

Cheers

Mike T

[GrimJosef]

If you look closely you might find a type code/factory code/date code on the EF86. The details of them are explained here https://www.vintage-radio.net/forum/...ad.php?t=25819. As Paul JD has pointed out Philips/Mullard EF86s do have some value, but for use in hi-fi and guitar amps rather than radios.

Cheers,

GJ

[Radio Wrangler]

Radio enthusiasts are generally interested in radio type valves, but prices for radio type valves are quite reasonable. The EC92 is a radio type, though not a commonly needed type.

It is the audio enthusiasts which have gone barmy. Some audio valves fetch prices which are staggering. They go for certain makes and worry about which plant made them and details of the shaping of the anode and of the getter and the colour of the writing! There is much written in their magazines and websites describing the nuances of the sound of each type. Those of us not engaged in their fancy don't seem to hear these differences. Anyway, prices for audio types have been jacked up by their demand. At the same time electric guitarists reckon that nothing sounds like a real valve amplifier (and at least there is some justification in this case) and some of them want to replicate the setups their heroes used, so that whomps up demand and prices for the types and makes guitar legends used.

The EF86 is an audio valve and is used in a number of highly respected amplifiers. It has high gain, reasonable noise performance, but is a pentode. The craziest fringe people want triodes. So the EF86 is a desirable valve, but not one of the craziest. Tungsram isn't one of the makers the cultists go crazy over, but there's nothing wrong with them, however, towards the end of the valve era some firms stopped manufacturing and bought valves in from those who still did. There is a possibility that though it doesn't carry the brand of a sought after maker, it might have been made by them. The batch code numbers give this away.

So you have one valve which might help someone fix a bit of old VHF gear and isn't worth a lot financially, and the other one is quite desirable, but isn't a rival for the price of rubies.

'Miniwatt' was a branding used by Philips, and Philips owned Mullard one of the most desirable makers. AND your writing is yellow. The batch code needs checking to be sure but it could be worth a few tens of pounds.

One thing to beware of, repairmen would go on a job carrying boxed new valves, and if they had to replace one, the old one got put in the box the new one came in, so there are lots and lots of used valves in new looking boxes. Getting it tested would tell you if it's an old work one.

David

[GrimJosef]

Originally Posted by Radio Wrangler

... It is the audio enthusiasts which have gone barmy. Some audio valves fetch prices which are staggering ...

One man's 'barmy' is another man's first edition Harry Potter book, David . Demand is what it is, and if we get into the habit of calling other enthusiasts barmy then we invite an unsympathetic response from the 'normal' folk if/when they find out how much gets handed over for a round Ekco !

Cheers,

GJ

[Paul JD]

The EF86 was used as a preamp valve in early versions of the Vox AC15 & AC30 guitar amplifiers, it was probably chosen because it was possible to get a lot of gain from a single stage and thus use less parts to keep costs down. The problem was it didn't stand up to the vibrations in a guitar amplifier very well and would often become microphonic so the design was soon changed to use ECC83 preamp valves which proved to be much more reliable.

More recently there have been a number of "boutique" guitar amps produced using the EF86 to try to recreate the early Vox tone hence their popularity in the guitar amp world.

[Radio Wrangler]

Originally Posted by GrimJosef

then we invite an unsympathetic response from the 'normal' folk if/when they find out how much gets handed over for a round Ekco !
Cheers,
GJ

No, no, no, no. They're completely different. The prices of round Ekcos are just plain daft.

David

[turretslug]

There aren't many valves that are utterly worthless, though there are some that one can tire of seeing. That said, they are usually little things like EB91s that don't demand much space anyway. A forum like this makes a useful means of re-homing glowing Cinderellas. Definitely don't chuck the EF86- it's likely that it will perform in much the same manner as most others and someone with a vintage amp who can look beyond snobbery and mystique will appreciate its functionality. The EC92 is a similar class of valve to the well-known EC90/6C4 but with a higher gm- it similarly has the saving grace of a 6.3V heater to widen appeal and will also be useful to someone. Very often with popular/in-demand valves, folk latch onto something that gets written about a lot in a self-perpetuating received wisdom, leaving other worthy types in the wilderness.

With round Ekcos (not Eckos, Echos etc....), there are a bundle if ticks-in-boxes that come together- era, style, Bakelite, populism and so on, most of the sought-after ones are somewhat unexceptional if adequate short-superhets under the skin. A CR100 is a far better MW/LW receiver (with SW thrown in to boot!) but not having the cachet or style, are difficult to give away. It's all about the image.

All valves are worth collecting, fascinating pieces of engineering and most still work 50 to 100 years after being made. If you want to make a profit out of valves start a rumour that the ones you have are good for audio.

My A22 round Ekco has shortwave.

[turretslug]

They are highly researched and exactingly made nuggets of technology that expanded many fields of science and engineering- it had been the thing to snort and sneer at anything that used valves for a long time but they pioneered many aspects of modern life that we now take for granted- TV, computers, avionics, navigation systems, it's difficult to think of fields of electronics where they didn't at least kick things off.

Just the fact that they were diligently and precisely assembled by those young enough and lucky enough to have precise hands and keen eyesight and likely on piece rates too makes it seem a shame to be too nonchalant about discarding them.

[music-centre]

A new EC92 always seems to be required for the Murphy A242 & A252 radios whenever I have come across one
Steve.

[Radio Wrangler]

Some amazing engineering went into valves.

Materials science for the emissive coatings on filaments and cathodes. Metals for anodes that reduce secondary emission, electron optics for the paths taken by electrons through the fields they experience in their flights.

Production engineering to make them cheaply. Automation and jigging. Huge turnover glassblowing with very few flaws.

Measurement of and optimisation of reliability.

Accelerated lifetime testing

Glass-metal seals with very low gas permeability.

The valve you hold in your hand today is the culmination of an immense amount of research. It's interesting that the plant with the biggest turnover, Mullard, Blackburn was at the forefront of reliability and low cost manufacture. They simply had the turnover to make good statistical analyses and fine-tuned their technologies and processes over an immense number of parts.

There are firms these days offering boutique valves for audio aficionados, but it seems they lack the knowledge and machinery that made the mass manufactured valves so consistent and reliable.

On the simple matter of reliability, there is an advantage to original period valves that recent parts cannot equal, and that is a good enough reason for preference. It's just that I explode in laughter when the pseudo science gets wheeled out by people desperate to justify their preference by any and all means they can grasp at.

It's critically important to keep a firm hold on the fact that it's all a hobby and ought to be fun. If it stops being fun, it's time to stop.

David