In praise of smaller bottles

[Tim]

A couple from GEC

A2134( got a few of them but never used one). I think that can also be used as a series pass element.

N78 (EL91 type thing)

although as others have said these "diddy" valves are really boy valves trying to do a man's job.

[Joe_Lorenz]

The ELL80 being another good example of a very compact valve which ran murderously hot and so had a short lifespan.

Just found this very interesting topic. So I'll try to say something good about that particular valve as it has been quite common in German stereo sets for a while (e.g. Neckermann / Koerting). In my youth I've seen many of them perishing quickly. But my wife was given a Quelle Senator radiogram some 20 years ago from a late neighbor. We shoved that into her ironing and needlework room, and it has been used constantly for several hours a week, up to now never serviced! Still running the first pair of ELL80s, and still amazingly strong! I wonder how long this will last!

On the other hand, I've got a Rock Ola juke box squeezing 25 Watts out of poor and miserable EL84s so that I've been tempted to replace them with somewhat sturdier.

Joe

[radiomobile]

As a 12 year old I used the ECL80 in many projects because they were plentiful and cheap as "pulls" from old TV's. For audio use the common cathode problem can be overcome by the use of a larger than usual bypass capacitor of around 100uF and an inter-stage coupling capacitor of no greater than 0.01uF. Mullard suggested using the valve, among other uses, as a cathode coupled multivibrator for TV line and frame timebase oscillators where of course the common cathode problem didn't arise.

[kalee20]

Originally Posted by Valvepower

Ooh, those 1p24b rod pentodes are new one on me

I’d best get my ECL80’s on a diet

Here's the size comparison!

They are amazing... I've heard of a pair being used to deliver 30W of RF (in Class C). Peak cathode current is specified as a whopping 800mA (2usec pulse duration).

They're rugged, too - rated to survive 4,000 shocks at 150g and constant acceleration of 100g.

[bobbyball]

I tend to collect German made radiograms and have a number of models from the like of Grundig, Saba, NordMende and so on all using the ELL80 and still sounding good after all these years. There is also the ECLL800 which crams an entire push-pull output stage in one bottle. Just acquired a Saba stereo set in fact which takes these valves. Also managed over the years to acquire a small stock of NOS examples of these valves.

Regarding the ECL83, pairs of these can be found as the output stages of a number of Bush (and Murphy equivalent) radiograms, and of course the earlier versions of the Bush SRP31 series - the "D" version using ECL86's in a rather strangulated design still producing about 3 Watts, although the Celestion speaker is of course quite small.

There were 2, as far as I know, commercial designs sold in the UK by largely UK manufacturers that use the ELL80, the first one being the Decca RP205 which uses this and a rather more obscure 6BR8 valves, it's claim to fame being featured in Emma Peel's flat in one of the "Avengers" series. The second model was made by STC (brands ITT, Regentone, RGD etc) and is a rather nice stereogram chassis using ECC series valves in the pre-amp stages and then ELL80's for the outputs. Can't remember the model numbers but they used Garrard record decks. Sound very nice, mono FM though.

BTW I also have a quite nice example of the Philco record player using the UCL83 as a single ended output. I can confirm myself that this sounds good! I think the model is the "Fashion"...