True, but still the newer version will have new stuff. That's what I meant. As for the prices....let's just not open the subject again.....(See posts about money hunters like elsevier)
Yes, This for example!
I say this tongue-in-cheek (I plan on building your amp, and have been Googling around)
Well it's being delivered by the 24th and I'm going on a holiday. So I will have a new book to read ! 😉
I notice a few pages (p. 224/225) down that he conflates shot noise with thermal/Johnson/Nyquist noise, a tradition since RDH4. Seems there's no fixing this; it's in the (Big Red) Bible.
Thanks,
Chris
Thanks,
Chris
As soon as you have significant space charge smoothing it is strange how the charge on the electron fades out of the picture but the temperature of the space charge appears instead. Shot noise ought to go like sqrt(eI), thermal noise like sqrt (kT). The latter is what occurs in normal valve 'shot noise'.
So Much Noise
My hat is off to DF96 in regard to understanding noise in valves. I believe the seat of knowledge regarding valve noise is in London.
Remember to mention Schottky when speaking of valve noise.
Reading The Big Red Bible I found a reference to a 1938 publication which is now consumed and full of postit notes, I could not come to mark in it. I also found a 1959 London Physics Society publication that says much the same as the 1938 book.
After reading the WWII volumes my impression of the treatment of noise goes like this: valve noise is, like poop is, there is not much we can do about it. As a result much of it is lumped in together and treated in a shorthand sort of way.
The radio designers discount flicker noise because it is an ailment in the audio frequencies. For radio frequencies the shorthand in valves the shorthand is to calculate noise as if it is from an equivalent value resistor. Also in the mix is the rule of thumb that states that flicker noise fades as the space charge and transconductance becomes larger. I believe, related to space geometry in the valve, tubes sort of follow the assigned rules. The radio designers post a list of usual suspect valves that they use that follow the rules. Some Valves like the 6J4 do not follow the rules as well.
I think that Mr. Jones follows the shorthand rules when speaking of valve noise. I do not think that this too far south.
My copy of edition #4 is on a slow boat from the UK and is due at my door July 25th.
DT
My hat is off to DF96 in regard to understanding noise in valves. I believe the seat of knowledge regarding valve noise is in London.
Remember to mention Schottky when speaking of valve noise.
Reading The Big Red Bible I found a reference to a 1938 publication which is now consumed and full of postit notes, I could not come to mark in it. I also found a 1959 London Physics Society publication that says much the same as the 1938 book.
After reading the WWII volumes my impression of the treatment of noise goes like this: valve noise is, like poop is, there is not much we can do about it. As a result much of it is lumped in together and treated in a shorthand sort of way.
The radio designers discount flicker noise because it is an ailment in the audio frequencies. For radio frequencies the shorthand in valves the shorthand is to calculate noise as if it is from an equivalent value resistor. Also in the mix is the rule of thumb that states that flicker noise fades as the space charge and transconductance becomes larger. I believe, related to space geometry in the valve, tubes sort of follow the assigned rules. The radio designers post a list of usual suspect valves that they use that follow the rules. Some Valves like the 6J4 do not follow the rules as well.
I think that Mr. Jones follows the shorthand rules when speaking of valve noise. I do not think that this too far south.
My copy of edition #4 is on a slow boat from the UK and is due at my door July 25th.
DT
Just so there is no confusion: the fact that valve 'shot noise' is expressed in terms of an equivalent noise resistance in the grid circuit says nothing at all about whether the origin of that noise is due to real shot noise (due to charge coming randomly in lumps of one electron at a time) or real thermal noise (e.g. from the hot cathode). It is just a convenient way of saying how much noise there will be in the anode circuit.
The actual calculation of 'shot noise' is complicated and involves some assumptions. It starts with the charge on the electron, as you would expect, but somewhere in the middle of the calculation when space-charge-smoothing is included the 'e' disappears and 'kT' appears, as estimates are made of the statistics of electrons leaving a hot space charge. IIRC this is before the point in the calculation where the anode noise current is transformed into an equivalent noise resistance. Hence my suspicion that 'shot' noise in a normally biased valve actually arises from thermal noise in the cathode space charge. I may be wrong.
You get true shot noise from a noise diode. No space charge means no smoothing, so the anode noise current comes just from sqrt(eI). I guess you could even use this to measure the charge on the electron!
Similarly, pentode partition noise truly arises from the discrete nature of charge. The sqrt(eI)-like term persists right through the calculation until it is converted into an equivalent thermal noise by using e/kT (room temperature thermal energy in eV) as a conversion factor.
The actual calculation of 'shot noise' is complicated and involves some assumptions. It starts with the charge on the electron, as you would expect, but somewhere in the middle of the calculation when space-charge-smoothing is included the 'e' disappears and 'kT' appears, as estimates are made of the statistics of electrons leaving a hot space charge. IIRC this is before the point in the calculation where the anode noise current is transformed into an equivalent noise resistance. Hence my suspicion that 'shot' noise in a normally biased valve actually arises from thermal noise in the cathode space charge. I may be wrong.
You get true shot noise from a noise diode. No space charge means no smoothing, so the anode noise current comes just from sqrt(eI). I guess you could even use this to measure the charge on the electron!
Similarly, pentode partition noise truly arises from the discrete nature of charge. The sqrt(eI)-like term persists right through the calculation until it is converted into an equivalent thermal noise by using e/kT (room temperature thermal energy in eV) as a conversion factor.
My copy is arriving three days early ......... tomorrow ! With all I'm reading about it , it has built up excitement before it's delivery. 😀
I got mine Monday (finally!). Been going through it to see what's new. I like that chart of distortion measurements for 6S45P vs. MOSFET used as a cathode/source follower. Lots of other good stuff too. Well worth it.
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Not sure if anyone wants to turn this into a discussion about the book or whether that needs a new thread? Thought I would start anyway...
I've been really enjoying it, it flows a lot better than the 3rd edition and it also seems to be more complete.
I thought I would build a couple of the low cost regulators into an Altec compressor to see how it performs, nearly complete so I am looking forward to the results. I bought a range of different caps for the supply, one of which was the Kelvin cap that MJ used from Supression Devices.
Although what arrived in the post wasn't exactly what I was expecting! Not sure what anyone would do with 5 leads per side....?🙄
New ones in the post so looking forward to trying them out. Has anyone else had some good or bad experiences with the new regulator?
Charlie
I've been really enjoying it, it flows a lot better than the 3rd edition and it also seems to be more complete.
I thought I would build a couple of the low cost regulators into an Altec compressor to see how it performs, nearly complete so I am looking forward to the results. I bought a range of different caps for the supply, one of which was the Kelvin cap that MJ used from Supression Devices.
Although what arrived in the post wasn't exactly what I was expecting! Not sure what anyone would do with 5 leads per side....?🙄
New ones in the post so looking forward to trying them out. Has anyone else had some good or bad experiences with the new regulator?
Charlie
Attachments
I am about to build an Aikido PP and haven't yet had time to start reading the book. Just did a cursory glance and decided that I would like it ! Looking forward to the month end . Holiday time has moved. 🙂
I just ordered the 4th Edition, a very belated Christmas present from last Christmas from my wife. (They cancelled the order months after Christmas..) 😀
Nineteen copies left at Amazon.. 😛
Nineteen copies left at Amazon.. 😛
I grabbed number 19 about 2 minutes after Kevin posted. I checked Amazon about an hour later and it still showed 19 left. They now show 14 left. I never got very far trying to read the Kindle version on my phone.
I have the Kindle version on my laptop and didn't get very far with it either, had I the Kindle Fire I suspect it would have been a different matter, it works quite well as a reader - my wife who swore ebooks were not for her now reads a couple of books that way a week. Looks pretty good to me too.
Mine should be here by the 20th..
The phone screen is just too small for my 60 year old eyes to read without constantly zooming in and out.
I recently got the new Google / Asus Nexus7 tablet. I think that it puts out the Fire. Same price, runs the Kindle reader, has the full Android 4.1 feature set, plays HD video too. The screen resolution is great, but the speakers suck. I think a vacuum tube docking station is in order....but that is a different thread.
I have read more of MJ4 in the week that I have used the tablet than the months that I had it on my phone.
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