that link takes me to the preceding post (14061).
Where did you intend that link to point?
best value
Merlin there is standard value 360 Ohm, no problem, and for other non-standard values there are solutions (parallel resistors etc).
Merlin there is standard value 360 Ohm, no problem, and for other non-standard values there are solutions (parallel resistors etc).
Yes, thanks, i saw that, and I have looked at that other thread, but not read all of it. My question, though, is "How does the resonance of the secondary vary with the value of the resistor?". That is, how critical is the resistor value to the amount of ringing? How far from optimum still gives an improvement, and how much improvement do we lose as we vary from optimum?
I also realize those questions belong in the other thread, and I thank you for posting your measurements. Really helpful stuff!
Hi Felipe,
One more opportunity to thank you. It wouldn't be possible without you.
I glad I have that jig. Requested data is coming soon.
You are asking subjective opinions, overdamped sounds bad and at this point I prefer without snubber, I can tell you the sounds improve more when more near is well damped the transformer without overdamp, I had a lot of fun playing with the jig.
He is not asking for "subjective" opinion.
He is asking for measurements when the damping resistor is less than optimum.
He is asking for measurements when the damping resistor is less than optimum.
For all friends who use Antek "AS-1236 - 100VA - 36V" for FSP.
Cx=10nF, Cs=150nF and Rs=7.4R
Attachments
Hi all, hi Salas,
I am assembling one pre, I am looking forward to switching it on!
I have a question, by no means a critic, I just would like to learn more.
The problem arise when I try to select 4 red leds for the riaa: I can't find a set that gives 7,75V. I reach less than 7V (more like 6,9V) when measured with a BF245A with Idss of ~4,7mA. Ok, I think I can replace one (or more than one) red led with a green one. But...
If I look at the curves for a standar led, in order to reach a "linear" region, where the voltage changes only a little varying the current, I should use a higher current than 4-5mA. Is there any reason for not doing so?
Thank you for your great design, I will let you know my feelings after the realization!
I am assembling one pre, I am looking forward to switching it on!
I have a question, by no means a critic, I just would like to learn more.
The problem arise when I try to select 4 red leds for the riaa: I can't find a set that gives 7,75V. I reach less than 7V (more like 6,9V) when measured with a BF245A with Idss of ~4,7mA. Ok, I think I can replace one (or more than one) red led with a green one. But...
If I look at the curves for a standar led, in order to reach a "linear" region, where the voltage changes only a little varying the current, I should use a higher current than 4-5mA. Is there any reason for not doing so?
Thank you for your great design, I will let you know my feelings after the realization!
The prototype's Leds were strong. Were giving more Vf than some other reds. If you got other to test or green or want to drive those you got with higher Idss Jfet so to push their Vf up the curve, its alright. 7.4V in total will also do. The voltage delta of each brand's type curve is not of interest because constant current is used.
thank you Salas.
So I assume that in your experience using the led string with an higher current gives no benefit since they are fed with constant current, correct?
So I assume that in your experience using the led string with an higher current gives no benefit since they are fed with constant current, correct?
Not to rely on a straighter portion of a VF-IF curve (which is not absolutely steep anyway), we eliminated the IF variability by using a CCS to feed the Leds. Just VF alone can't vary on its own, wherever on the curve.