Am I getting very nerdy when I ask if it would be better to put Non Magnetic resistors in de Paradise? Would go for the Vishay CMF 55 143 series... Or is the normal CMF55 good enough? I think in the MC input, non magnetic can work, because of the tiny signals flowing here. Or Nerd??
why not... for the 33ohm resistors in the input stage that may make sense, although i never tried and regular CMF55 worked fine for me.
Hi,
Now how would it be called?
Maybe "Calvin in Paradise"?
Of course could I sympathize more with that than Rev. B or MK2
jauu
Calvin
Ps. It was great to see you guys, Joachim, Alfred, Jonathan and all the other nice 'nerds' at the show.
yes, it was great to see you although very brief, sorry for that!
Calvin in Paradise sounds good to me, and I will see what I can do about that. Hey Calvin, are you actually listening to Vinyl? Just curious...
It is really a pleasure to work with these PCB's ... I enjoy every single step in the build
Not very sure though about matching of the J310 in the output buffer. As I haven't read about them in the guide, I could assume I can pick them straight out of the bag. Still I remember reading some directions from Joachim or Alfred, but can't get that post. Should I get them with Vp bigger than 3V if I remember correctly? I have a custom matching device and I get in my batch only very few transistor with Vp bigger than 3 V (I know, actually it is negative, so it should be lower than -3V).
i suppose this rationale should apply only for the upper J310, that works as a cascoded voltage controlled current source with 2SK170. And the idea should be to offer sufficient voltage for 2SK170, also if I remember correctly.
I know, everybody is excited about the new old Calvin buffer but it will be highly appreciated if someone can point me to that post, or if somebody can bring more details to the requirements of the J310 parameters in the old/new output buffer
Not very sure though about matching of the J310 in the output buffer. As I haven't read about them in the guide, I could assume I can pick them straight out of the bag. Still I remember reading some directions from Joachim or Alfred, but can't get that post. Should I get them with Vp bigger than 3V if I remember correctly? I have a custom matching device and I get in my batch only very few transistor with Vp bigger than 3 V (I know, actually it is negative, so it should be lower than -3V).
i suppose this rationale should apply only for the upper J310, that works as a cascoded voltage controlled current source with 2SK170. And the idea should be to offer sufficient voltage for 2SK170, also if I remember correctly.
I know, everybody is excited about the new old Calvin buffer
but it will be highly appreciated if someone can point me to that post, or if somebody can bring more details to the requirements of the J310 parameters in the old/new output buffer Hi metallicus69, the actual VTH of the J310s is not very important, values between 2.5V to 3V are just fine. Ideally, the upper and lower transistor should be roughly the same but it doesnt matter much.
The thresholds of the 2SK170s matter more, they should be close. If they are not, the buffer will exhibit a DC offset voltage, measurable between "RIAA EXT" connector and the output connector. But, the servo will regulate that away no problem.
hope that helps!
The thresholds of the 2SK170s matter more, they should be close. If they are not, the buffer will exhibit a DC offset voltage, measurable between "RIAA EXT" connector and the output connector. But, the servo will regulate that away no problem.
hope that helps!
Thanks hesener, it helps indeed!
In the end I picked enough J310 with Vp around 3V (+/- 10mV).
What is confusing in your post is "thresholds of the 2SK170s", as this is only one in that stage. What exactly is important in those thresholds? (related to J310?)
I imagined that the servo will take care of reasonable amounts of parameters spread, but I prefer that it's doing less work. For this, I matched everything very tight (also between channels), and even the input and mirror transistors will be thermally coupled and as much as possible isolated from the air movements (I hope).
Only this output buffer gave me some question marks regarding the way I should pick/match the correct components/pairs but if it's not very important, I will try to pick the pairs between channels (close Idss for 2SK170BLs). I will explore the Calvin buffer for sure in the future, but as of now, I will build it as it is.
Cheers!
In the end I picked enough J310 with Vp around 3V (+/- 10mV).
What is confusing in your post is "thresholds of the 2SK170s", as this is only one in that stage. What exactly is important in those thresholds? (related to J310?)
I imagined that the servo will take care of reasonable amounts of parameters spread, but I prefer that it's doing less work. For this, I matched everything very tight (also between channels), and even the input and mirror transistors will be thermally coupled and as much as possible isolated from the air movements (I hope).
Only this output buffer gave me some question marks regarding the way I should pick/match the correct components/pairs but if it's not very important, I will try to pick the pairs between channels (close Idss for 2SK170BLs). I will explore the Calvin buffer for sure in the future, but as of now, I will build it as it is.
Cheers!