Because of some project at work unfortunately I am fully booked these weeks. I haven't fully done yet my CFP homework and so far I do not know what questions are really important.
So far, still very happy with your schematic using 317 (1BJT equivalent).
However, concerning the CFP,option coming from the 2BJT world, can you recommend a schematic to beat the THD+N of 317 by 20dB ?
What level is the optimization work involved for stability vs performances? Advanced/experts, or accessible also to guys like me?
We are talking line level, hence keeping the margin to +12dBu is appreciated.
I am considering this CFP option because the 317 might have a signature: as a personal remark I think that with some 15ips hot tapes it does loose a bit of transparency (compared to Fostex R8's line amp, I am sure sure if I understand it correctly but it seems to be the Pin9 of IC2.U2 CX20187).
Explanation could be also this: I have recently upgraded my A77 to 15ips, but still using the previous NAB EQ for 7,5ips (no time and no Ref tape for 15ips). Therefore the program is a bit modified, but despite Tone control adjustments it might also be the reason for the allegedly losing a bit of transparency.
I know, A77 EQ on 15ips is a must for comparing apples with apples. Until this happens, I am trying to prepare a CFP option just in case.
Hi thank you very much again
I will do it for sure because for instance i like also Toshiba bjts a lot Mostly because i have seen them used in very expensive units
I guess that they tend to use the best when they want to make the best quality products. And they are not that expensive as well. Great parts.
If i understand well there is no way to import these models in the LTSpice library ?
Nevertheless to be able to pick them up directly from the library would be very handy
I missed this extremely elegant circuit
Thanks so much for suggesting this. I only have two questions
1) will any LM317 provide good results? (the component used here is quite rare and difficult to get)
2) is the dissipated power given by (Vin -Vou) multiplied by the current Iout? up to what power will there be a need for a heat sink?
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With 2Bjt's, the CFP is really the best possible. You can tweak the resistors values, for example to increase the bias current, to make it much larger than the peak current in the load, but this won't fundamentally change the character of the circuit.
The CFP will have a lower noise than the 317, but the THD of the 317 will be lower.....
Hi ! sorry again but i cannot find this file on the pc
I have searched and found nothing This is the biggest issue now
I understand that once the file is found i can just copy and paste the model and save the updated file
But again the file seems missing
Maybe it is hidden ? i am getting mad
The previous version was so much more straightforward I have seen tutorials and the library showed up very easily
They have complicated the sw imho
To add a new model to the library should be the easiest thing to do I guess
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Hi thank you so much again The folders were hidden and i could not see them Now i see all the folders/files
I have then added some bjt models taken from the Cordell's file but the program cannot let me to save the mods I mean i edit the standard.bjt file > i save the mods > when i open it again the mods do not show up And when during the sim i pick the bjt the added models of course do not show up in the list
Maybe there is some kind of protection of the original file I will try again soon
The folders were hidden and i could not see them Now i see all the folders/files I have then added some bjt models taken from the Cordell's file but the program cannot let me to save the mods I mean i edit the standard.bjt file > i save the mods > when i open it again the mods do not show up And when during the sim i pick the bjt the added models of course do not show up in the list
Maybe there is some kind of protection of the original file I will try again soon