The cost of that ECC83 valve?

[Radio Wrangler]

You will find that whatever level of prowess at hearing is claimed, the skill at avoiding getting involved in a true scientific test is unquestionably greater

Numerous attempts have shown that such an event is never going to occur in such a way that all parties would accept the outcome.

The audiophiles derive a great deal of pleasure from their pursuit, and we must remember that once in the past, the subjectivists were definitely right about one thing. Some amplifiers really did sound poor despite measuring well in the tests of the day. The measurement people thought everything was covered, and they had missed a couple of important things. It would be wrong to forget this. It would also be wrong to extrapolate it into a belief that the subjectivists must always be right.

I want to keep an open mind. If someone tells me that something sounds unexpectedly good or unexpectedly bad, I want to find out why.... I might be missing something.

Maybe ECC83 with smooth anodes do sound different to those made when stiffening ribs were the norm, but if so, that difference ought to be perceptible to a skilled person who has only heard the valve. With some confidence that the difference is real and repeatable, the effort of investigating what other changes there are in the construction of the valve can be justified and maybe we can find a definite cause?

What I can't accept are theories with no investigation behind them. The suggestion that spending a lot more money on the mains cable of this lap-top would reduce the radiated 50Hz magnetic field and thus decrease the disturbance of the pixels in its LCD resulting in the fonts looking crisper... was made up on the spot, but repeat it enough in the right places and other people will go around saying it.

David

[trickie_dickie]

Just found this. American $129.99. They're 'avin' a larf.

[HamishBoxer]

It is a gift!Sorry could not resist but back to reality the price is unlikely ever to come down on not just ECC83 but other popular types as well.

Trying to stay close to topic i remember being horrified at £7 for a UL41.

[cmjones01]

Originally Posted by ITAM805

Just opened up my 60's AC30 and found 3 Mullard ECC83's, a Tungsram and a couple of these GDR brands. Are they likely been of a particular brand or just some East German plant?

As I understand it, the communist economies didn't really have brands in the way we'd understand them - all the companies in a particular industry tended to be brought together under a single umbrella 'brand'. In the GDR, electronics was all under the RFT 'brand'. It's probably possible to track down which factory RFT valves were made in, with enough research. I guess the exported valves didn't use the RFT marking because it didn't mean anything to people in the western world.

Chris

[Jeremy M0RVB]

Originally Posted by trickie_dickie

The best ECC83s I ever had were CV4004s back in the 60s.They had a box shaped anode unlike the usual shape.

This has a basis. CV4004 / M8137 is a 'reliable' variant of the ECC83 - these had to withstand shock and vibration tests. The mica supports etc. are put together better. I have a paper about the construction methods somewhere.

[G6Tanuki]

Originally Posted by cmjones01

As I understand it, the communist economies didn't really have brands in the way we'd understand them - all the companies in a particular industry tended to be brought together under a single umbrella 'brand'. In the GDR, electronics was all under the RFT 'brand'. It's probably possible to track down which factory RFT valves were made in, with enough research. I guess the exported valves didn't use the RFT marking because it didn't mean anything to people in the western world.

Some RFT valves actually came in boxes that had the manufacturing plant printed on them. "VEB Röhrenwerke Anna Seghers" is one that springs to mind. ("VEB" being "Volkseigener Betrieb" - essentially "Publicly owned operation" - what us Wessis would call a nationalised industry.).

I once bought some valves which came from the Anna Seghers factory: they had used rolled-up local newspapers to pack the space between the valves and the boxes. The German-master at my school was most intrigued and asked me where I'd got them!

[vidjoman]

Originally Posted by trickie_dickie

Just found this. American $129.99.

Cheap as chips. There is a pair (no mention of NOS) of ECC83 Mullard's on eBay @ £281 tested, and they must be secondhand and claim to be from 1956. Still time to bid if you're silly enough.

[daviddeakin]

Thought this might be relevent. I just measured the distortion in my best set of ECC83s (checked for health on a curve tracer). They were run with a 900uA constant current source, -1.4V bias, 300V HT, fully buffered so the load on the valve was tens of megohms, 10k grid stopper. The rise at low output levels is the noise floor, not distortion. They clip at about 50Vrms output because the constant-current source runs out of voltage.

For a start 300V HT won't matter if you are using a constant current source (until the output gets that far), most amplifiers have a resistive load on such valves and there is a significant load on the output. Never the less, it is an interesting result.

It would be interesting to repeat the measurements with, say, a 100k anode resistor and a 1M ohm 20pF load. Maybe at various HT voltages too.

[GrimJosef]

It would also be interesting to pick a few valves which were nominally all of the same type (say all Mullard I62's or I63's) and to check what the spread between nominally identical valves is. Your graph as shown could mean that Sovteks really are generally better than yellow print Mullards. Or if the spread of Mullards is larger than the difference between your particular Mullard and your particular Sovtek then all it shows is that all ECC83s are pretty much the same and it's more important just to pick a 'good' one, not to worry about who manufactured it.

I think it's noteworthy that back in the day, when the valve business was huge and the resources would easily have existed to have done it, manufacturers never seemed to advertise their valves with graphs showing how much better theirs worked than the competition's. Instead they concentrated on longevity, or ruggedness, or the quality of service you would get. I take it that this was because in fact all ECC83s measured pretty much the same and there was no mileage in trying to convince buyers that yours would work any better than anyone else's.

Cheers,

GJ

[daviddeakin]

Originally Posted by GrimJosef

It would also be interesting to pick a few valves which were nominally all of the same type (say all Mullard I62's or I63's) and to check what the spread between nominally identical valves is.

Yes that would be very interesting. Unfortunately, I don't have a collection of the same type!

[k_yller]

Originally Posted by cmjones01

As I understand it, the communist economies didn't really have brands in the way we'd understand them - all the companies in a particular industry tended to be brought together under a single umbrella 'brand'. In the GDR, electronics was all under the RFT 'brand'. It's probably possible to track down which factory RFT valves were made in, with enough research. I guess the exported valves didn't use the RFT marking because it didn't mean anything to people in the western world.
Chris

to clarify
RFT= Rundfunk und Fernsehenstechnik -broadcasting and television technic
yes it was one single "umbrella" brand
VEB=Volkseigenerbetrieb its means something like people-owned enterprise (in reality state-owned)
its quite simply to trace down specific manufacturer
for valves was:
VEB werk fur fernsehelektronik berlin
VEB funkwerk erfurt
VEB rohrenwerk anna seghers neuhaus (old RWN logo)
VEB rohrenwerk anna seghers neuhaus (new logo -better quality)
VEB rohrenwerk muhlhausen
valves for domestic market and for eastern block countries was always (?) marked with specific "VEB"
exported to west was only marked as RFT
worst GDR valves are el84, el86, ecc85