Because between the different manufacturers there are many differences in the physical construction and materials used to arrive at (theoretically) the same electrical performance. And tubes wear out with use.
Also, nobody could measure back then like you can today... When those tubes were designed, the best research lab in the world didn't have access to the information you can get off your basic digital scope.
Also, nobody could measure back then like you can today... When those tubes were designed, the best research lab in the world didn't have access to the information you can get off your basic digital scope.
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filament starving is for sissies 
same as in case when using CCS heating for voltage oriented filaments , where you need to fine tune CCS observing voltage - for each tube separately - you also need to fine tune starving filament voltage not for every brand , but even for every batch of tubes in same brand
so - every old toobster will tell ya - leave it kiddoe - that hassle is nothing else than trouble - feed them as intended , and then you'll have expected behavior across entire
life span
same as in case when using CCS heating for voltage oriented filaments , where you need to fine tune CCS observing voltage - for each tube separately - you also need to fine tune starving filament voltage not for every brand , but even for every batch of tubes in same brand
so - every old toobster will tell ya - leave it kiddoe - that hassle is nothing else than trouble - feed them as intended , and then you'll have expected behavior across entire
life span
That doesnt really explain the differences in frequencys to me. My wild guess is that I'm looking at a combination of filament interference and microphony planting from the mains tranny. Maybe. Wild guess, but can be tested.
filament starving is for sissies
same as in case when using CCS heating for voltage oriented filaments , where you need to fine tune CCS observing voltage - for each tube separately - you also need to fine tune starving filament voltage not for every brand , but even for every batch of tubes in same brand
so - every old toobster will tell ya - leave it kiddoe - that hassle is nothing else than trouble - feed them as intended , and then you'll have expected behavior across entire
life span
Old toob guy. Those fellows are intended for stuff that cant reproduce any 50 Hz and also as noice cancelling push pull output toobies configs. Then 6,3 AC is fine, even as it would have been a DHT. But we're in a different area now. Suggestions?
clarify "those fellows"
too many threads in same time , too many posts ........ and I couldn't cope with all mistakes you made in measurements ( taking in account that you were in good company ) .
so - what's the problem now ?
Those fellows is the 6V6es. In a push pull output tube config its ok with several voltages of ripple and it cancels out in the OPT. In an SE preamp config millivolts apperantly makes differences to the result.
I am aware of that this is not their intended use, as I am of my faulty measures (I'm here to learn) but I really think this is a perfect example of learning to both tackle the problems and use the tools to analyze it.
If you dont agree please say so.
Look at the last 3 pics. They are taken with the same config, same environment just 3 different fellows. Explain the differences.
I am aware of that this is not their intended use, as I am of my faulty measures (I'm here to learn) but I really think this is a perfect example of learning to both tackle the problems and use the tools to analyze it.
If you dont agree please say so.
Look at the last 3 pics. They are taken with the same config, same environment just 3 different fellows. Explain the differences.
differences as result of different physical/electrical virtues of each toob
you still need to learn that each tube is result of hundreds of small very precise steps in manufacturing procedure and that there are hardly two same tubes in existence
but - as I wrote already - heating of tube is fundamental , most important condition for exploitation ; heat them as they intended to be heated , but in most proper way you can make it .
that way differences and spread of electrical characteristics will be minimized
CCS based heating is my choice ;
edit : few mishaps :
- I'm not here to not agree with learning , steepness of someone's learning curve etc. ...... just said that I didn't had time/energy to follow or even help , in case that I can and know how to help
- SE came historically before PP , so that was their intended use - especially in time when each uF was golden
you still need to learn that each tube is result of hundreds of small very precise steps in manufacturing procedure and that there are hardly two same tubes in existence
but - as I wrote already - heating of tube is fundamental , most important condition for exploitation ; heat them as they intended to be heated , but in most proper way you can make it .
that way differences and spread of electrical characteristics will be minimized
CCS based heating is my choice ;
edit : few mishaps :
- I'm not here to not agree with learning , steepness of someone's learning curve etc. ...... just said that I didn't had time/energy to follow or even help , in case that I can and know how to help
- SE came historically before PP , so that was their intended use - especially in time when each uF was golden
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Apperantly heating is one thing that needs to be investigated using those kinds of tubes for this intention. My first try was AC, second elevated AC and now some other ways.
Note that I have yet not listened to the different configs. I got stuck on measurment results and interpretation of the same.
I agree with both 6L6 and ZM that the tube charm is much about their individual charachteristics. Im still puzzled about the differences in curves frequencys tho. I think I can gather around 50-100 different 6V6es without going to far. A stupid thing would be to measure them all.
Hey ho, captain Ahab!
Note that I have yet not listened to the different configs. I got stuck on measurment results and interpretation of the same.
I agree with both 6L6 and ZM that the tube charm is much about their individual charachteristics. Im still puzzled about the differences in curves frequencys tho. I think I can gather around 50-100 different 6V6es without going to far. A stupid thing would be to measure them all.
Hey ho, captain Ahab!
heater PSU must be rock solid stable , same as anode PSU
make first one in quality as you have second one , and result must be good ;
if you have trouble/disturbance from dirty (input) side of any PSU , only cure is to make it more remote , while keeping final reg elements near load ( tube itself)
choke in anode PSU is on dirty side - ringingzingingspitting creature , exactly intended to do these nasty things , instead of tube itself
make first one in quality as you have second one , and result must be good ;
if you have trouble/disturbance from dirty (input) side of any PSU , only cure is to make it more remote , while keeping final reg elements near load ( tube itself)
choke in anode PSU is on dirty side - ringingzingingspitting creature , exactly intended to do these nasty things , instead of tube itself
From the bottom:
My linear PSU dont get any more stable then it is now I think. We're talking uV in ripple here. I could stabilize it to mains variations and tempdrifts but I think that is to chase shadows atm. I could maybe harvest some uV ripple by decoupling the last filtercap. I will try that.
I have no regs atm, all is linear.
Thing is, measures lead me on another path. The path that tubes are individual and in this config they need individual treatment.
My linear PSU dont get any more stable then it is now I think. We're talking uV in ripple here. I could stabilize it to mains variations and tempdrifts but I think that is to chase shadows atm. I could maybe harvest some uV ripple by decoupling the last filtercap. I will try that.
I have no regs atm, all is linear.
Thing is, measures lead me on another path. The path that tubes are individual and in this config they need individual treatment.
Hey Bas, what's up? Long time no see.
Still using the 6V6 pre in that clever wooden enclosure regularly?
By the way as we speak I'm exporting a dxf for a friend to cnc a plate for the Salas 6v6. (He just completed a diy cnc machine) So I'm curious to see how well it will turn out...Smallest bit he has is 2mm..hence the font and thickness. Still it should look nice.
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