I will try all of those suggestions
Regarding 1) I thought I could lower the caps because the circuit is now seeing 1 Meg as opposed to 10k or 20k.
I misread your values of R8,R16. Sorry.
You could use 100k for those and then 1u for the caps.
Patrick
You could use 100k for those and then 1u for the caps.
Patrick
> Or pick some bigger Jfets.
> Hint: Look at some of the switches.
You mean bigger in terns of package size than TO92 ?
Patrick
> Hint: Look at some of the switches.
You mean bigger in terns of package size than TO92 ?
Patrick
The only thing I can think of that Nelson might be suggesting here is the Power Jfets from Semisouth. So it would have to be a D1 circuit.
I will have a look around and see what I can find.
I will have a look around and see what I can find.
It's worth noticing that such a buffer is topologicaly a push-pull and its' sound character is somewhat different. Its' input capacitance is significantly higher too. That's the price to be paid for higher drive capability...
All correct, except that before I put a 4.7n at the output of the IV stage, I am not too worried about 41p at the input of the complementary follower.
A push-pull buffer stage has less distortion and lower output impedance.
But use what you fancy. All matter of taste.
Patrick
A push-pull buffer stage has less distortion and lower output impedance.
But use what you fancy. All matter of taste.
Patrick
so biasing source at AVCC/2 (or close enough, the exact V doesnt seem to matter all that much) is no problem due t o being Vground right? for sabre users input Z really should be quite a bit lower, i'm not even sure paralleling the jfets will get us there for best DNR; but the sound is another matter I guess. I have DCB1 PCBsready and waiting for a reason and this seems like a good one, but I need to tick a few more boxes yet. BTW this would be for ackodac not buffalo II. same diff though as far as numbers that matter here.
linear systems JFETS would seem the logical choice here no?
linear systems JFETS would seem the logical choice here no?
Hello
To use the Zen I/V Converter with a TDA1541A, do it need any modification ?
Thank
Bye
Gaetan
To use the Zen I/V Converter with a TDA1541A, do it need any modification ?
Thank
Bye
Gaetan
Hello
I can't find any 2SK170 and 2SJ74 here arround.
Do it need to be very low noise jfet ?
Bye
Gaetan
I can't find any 2SK170 and 2SJ74 here arround.
Do it need to be very low noise jfet ?
Bye
Gaetan
That's too bad. There are lots of DIYdac's using that chip. We should focus on making it optimal, or better than resistor I/V
Can someone well versed in dac's, present a list here that would be a reasonable match with this circuit.
How do I determine whether 5 Ohms to 15 Ohms is going to be a problem for a particular dac?
How do I determine whether 5 Ohms to 15 Ohms is going to be a problem for a particular dac?
Do you have any data on that? The manufacturer does not
mention voltage degradation in the data sheet.
😎
TDA1541A datasheet (page 7) says:
"Notes to the characteristics
1.To ensure no performance losses, permitted output voltage compliance is ±25 mV maximum."
I made 3 DACs with that chip, tried various I/V solutions and found out that it really sounds best with DAC's output as close to 0V as possible.
Snap from datasheet:
Attachments
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Hello
Normally, for the TDA1541A, wen using a resistor I/V, you need your resistor to be arround 30 ohm.
How much ohm impedance are the ZEN I/V ?
Anyone compared the ZEN I/V to the D1 ?
Thank
Bye
Gaetan
Normally, for the TDA1541A, wen using a resistor I/V, you need your resistor to be arround 30 ohm.
How much ohm impedance are the ZEN I/V ?
Anyone compared the ZEN I/V to the D1 ?
Thank
Bye
Gaetan