Anyone know which of these tubes is the left and the right ?
Trying to figure out because I have a pair of 12AX7 that are the same and one different. So I’d like to install the pair as left and right...
Thx
Trying to figure out because I have a pair of 12AX7 that are the same and one different. So I’d like to install the pair as left and right...
Thx
Attachments
It does not matter to the tube whether you use it for the left or the right channel. Both halves of the tube are the same.
Looks like each half of the 12AX7's is used for one channel, so non of the 12AX7's is used for only one channel.
The 12AX7 at the bottom of the picture contains the first stage (one half per channel), the middle the seconds stage (one half per channel) , and the upper one (no surprise) the last stage (one half per channel).
The 12AX7 at the bottom of the picture contains the first stage (one half per channel), the middle the seconds stage (one half per channel) , and the upper one (no surprise) the last stage (one half per channel).
Hmmm,i've been looking at that very preamp.Based on the Marantz 7.I saw it on Aliexpress but they say no shipping to Canada? May I ask where you got yours?I think it was listed as $110-$145 U.S. plus $57 shipping to the U.S.I built a LTspice sim of the circuit,it has low distortion,dominant 2nd harmonic,positive phase.
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At the fear of causing a worldwide argument as to different countries dogma on this seemingly touchy subject I will put forward the British industries ( when it existed ) Valve Standard Nomenclature --registered with the Pro-Electron body that existed in Europe (at least ) back in my day and used by EVERY British tube manufacturer including Mullard --and yes I have the Mullard industrial valve books where this is officially stated at the beginning .
This agreement also covered the alphabetical designations after the valves .
Anode one =pin 6.
Grid one =pin 7.
Cathode one=pin8.
As I said this is 2020 and times change but think on-- many early Japanese copies of valve design were "borrowed " from the UK just like the early motorbikes which complete r**-off,s of the Triumph Twin,
and I can prove that .
Valve=Tube .
Anode=Plate.
This agreement also covered the alphabetical designations after the valves .
Anode one =pin 6.
Grid one =pin 7.
Cathode one=pin8.
As I said this is 2020 and times change but think on-- many early Japanese copies of valve design were "borrowed " from the UK just like the early motorbikes which complete r**-off,s of the Triumph Twin,
and I can prove that .
Valve=Tube .
Anode=Plate.
True, but that would apply to European made ECC83.
This one is 12AX7 the American version so American designations would apply.
To boot, 12AX7 was *invented* by an American company (RCA) so they hold seniority 😀
This one is 12AX7 the American version so American designations would apply.
To boot, 12AX7 was *invented* by an American company (RCA) so they hold seniority 😀
What about Brimar/STC?
I’m not quite sure what you mean by this, but what about the ECC32, ECC33, ECC34, ECC35, ECC40, E80CC, ECC87, ECC807 and ECC8100?
Cant argue with that JMFahey --"different strokes for different folks "-
Muhammed Ali --November -1966 -- yes again an American .
I do have some American tube equivalent books including the great USA -Radio troubleshooters Handbook -1943 by American -Alfred A. Ghirardi -third revised edition by Technical Division -Murray Hill Books Inc.-232 Madison Avenue -NY 16.
Not only does this large book cover all USA tube radios it covers old US record players and more importantly all USA automobile radios and a complete tube equivalent and spec. range ( up to 1943 ) .
Its full of great info including the dial lights used so for American viewers I can quote RCA etc tube specs including cathode resistors just the job for that multi millionaire on TV who buys very old US autos.
Muhammed Ali --November -1966 -- yes again an American .
I do have some American tube equivalent books including the great USA -Radio troubleshooters Handbook -1943 by American -Alfred A. Ghirardi -third revised edition by Technical Division -Murray Hill Books Inc.-232 Madison Avenue -NY 16.
Not only does this large book cover all USA tube radios it covers old US record players and more importantly all USA automobile radios and a complete tube equivalent and spec. range ( up to 1943 ) .
Its full of great info including the dial lights used so for American viewers I can quote RCA etc tube specs including cathode resistors just the job for that multi millionaire on TV who buys very old US autos.
PCL200- do you mean the ORIGINAL Brimar company or the new(ish ) -
Brimar Thermionic Valves --not the same companies .
The old --ECC32/33/34/35/40 all have the same designation in Wireless World -1964/66 editions ( I have both in paperback and downloaded ) .
E80CC is UK military spec .
ECC807 has different pinouts ( no heater centre tap ) but is -
Anode one =pin 8.
Grid one=pin 9.
Cathode one=pin 1
Dont have - ECC87 but do have ECC88 which is the same pinout as -
ECC85/189-
Anode one=pin 6.
Grid one=pin 7.
Cathode one=pin 8.
Okay I hold my hand up never heard of ECC8100--looked it up --aha ! its German - Telefunken --looks like an HF ( VHF ) RF amplifier tube .
Brimar Thermionic Valves --not the same companies .
The old --ECC32/33/34/35/40 all have the same designation in Wireless World -1964/66 editions ( I have both in paperback and downloaded ) .
E80CC is UK military spec .
ECC807 has different pinouts ( no heater centre tap ) but is -
Anode one =pin 8.
Grid one=pin 9.
Cathode one=pin 1
Dont have - ECC87 but do have ECC88 which is the same pinout as -
ECC85/189-
Anode one=pin 6.
Grid one=pin 7.
Cathode one=pin 8.
Okay I hold my hand up never heard of ECC8100--looked it up --aha ! its German - Telefunken --looks like an HF ( VHF ) RF amplifier tube .
I mean the original Brimar.
I probably still don't understand what kind of rule you are referring to. It looked to me you were pointing out a rule holding that a perticular triode section in a double triode is called system one (and the other system two) and that this has to do with the pin-out of the tube. I never heard of that rule (but there's a lot I don't know). I just knew that there are many European double triodes that don't seem to follow that rule.
I probably still don't understand what kind of rule you are referring to. It looked to me you were pointing out a rule holding that a perticular triode section in a double triode is called system one (and the other system two) and that this has to do with the pin-out of the tube. I never heard of that rule (but there's a lot I don't know). I just knew that there are many European double triodes that don't seem to follow that rule.
The original Brimar kept to the same standard as Mullard .
Pro Electron - Wikipedia
I think you have got the wrong idea PCL200 ,your question originally was -- "what is the first section " well according to Pro-Electron its the one I mentioned and as most European tube manufacturers ( Mullard is Philips ) registered with Pro-Electron they used the same technical designations.
Look at a Mullard ( small ) data book scroll down to ECC81/82/83 and you will see what I mean -- one tick is one --two ticks is two.
https://www.rsp-italy.it/Electronics/Databooks/Mullard/_contents/Mullard%20Databook%201965%201966.pdf
This might interest you Mullard Audio Valves data -
https://www.rsp-italy.it/Electronic...ntents/Mullard Valves for Audio equipment.pdf
Pro Electron - Wikipedia
I think you have got the wrong idea PCL200 ,your question originally was -- "what is the first section " well according to Pro-Electron its the one I mentioned and as most European tube manufacturers ( Mullard is Philips ) registered with Pro-Electron they used the same technical designations.
Look at a Mullard ( small ) data book scroll down to ECC81/82/83 and you will see what I mean -- one tick is one --two ticks is two.
https://www.rsp-italy.it/Electronics/Databooks/Mullard/_contents/Mullard%20Databook%201965%201966.pdf
This might interest you Mullard Audio Valves data -
https://www.rsp-italy.it/Electronic...ntents/Mullard Valves for Audio equipment.pdf
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The original Brimar also sold tubes (also in the UK) while not using the coding that was mostly used in Europe (this was before Pro Electron, which according to your was formaly establihed in 1966, so very late in the 'old' tube era). An example is the 6BR7, but there are many more.
Well, my question was: How come there are so many double triodes with codings mostly used in Europe that don't follow the rule you say exists (see post #7). I don't have an answer yet. The link to the Wikipedia page doesn't provide an answer either. If the rule was only established in 1966, than it is of little practical value anyway; most double triode types date from before that time.
Well, my question was: How come there are so many double triodes with codings mostly used in Europe that don't follow the rule you say exists (see post #7). I don't have an answer yet. The link to the Wikipedia page doesn't provide an answer either. If the rule was only established in 1966, than it is of little practical value anyway; most double triode types date from before that time.
When a Standard ruling is proclaimed in engineering ( of any sort ) previous years of intense study by engineers has already taken place it is logical that a reason for this numbering of separate triode sections in a single tube is given.
The reason is to conform to an established tube base pin connections so that a schematic diagram conforms to a Standard Pattern as far as wiring is concerned .
This aids stability and conformity so that recommendations can be used as to correct circuit design .
In the days of the early tubes there wasn't a fixed standard for wiring up twin triodes/twin pentodes so to find out what was the input section you either had to be a dealer with a "blueprint " ( early circuit diagram ) or if DIY public you had to open it up and look under it to see how it was wired .
Thats one reason early tube radios/amplifiers etc had screw off plates I removed 100,s to do a quick check .
Philips usually had a cardboard one .
The reason is to conform to an established tube base pin connections so that a schematic diagram conforms to a Standard Pattern as far as wiring is concerned .
This aids stability and conformity so that recommendations can be used as to correct circuit design .
In the days of the early tubes there wasn't a fixed standard for wiring up twin triodes/twin pentodes so to find out what was the input section you either had to be a dealer with a "blueprint " ( early circuit diagram ) or if DIY public you had to open it up and look under it to see how it was wired .
Thats one reason early tube radios/amplifiers etc had screw off plates I removed 100,s to do a quick check .
Philips usually had a cardboard one .
Still no answer. As long as you don't prove the existence of the rule you say is there (where exactly is this rule described? since when is it in force?), I don't buy it.
You don't need to buy it its a fact of life that early electronic circuits for the public didn't conform to industry standards .
In the 30,s many innovations took place which resulted in many patents , unusual circuits where motorisation took place / multiple push buttons /multiple stages etc all non standard .
By the way the USA had /has its own system of conformity so are you going to criticize that too ?
In the 30,s many innovations took place which resulted in many patents , unusual circuits where motorisation took place / multiple push buttons /multiple stages etc all non standard .
By the way the USA had /has its own system of conformity so are you going to criticize that too ?
Still no proof.
And by the way: I didn't criticize any system. I just doubt the existence of the rule you described.
And by the way: I didn't criticize any system. I just doubt the existence of the rule you described.
