The problem with those may be the Ciss at min 2300 pF
be nice if same one more expert than me could clirify pro and con of this as far as (I think I know) this may efect the sound signature
The TO3P is certanly a bonus
be nice if same one more expert than me could clirify pro and con of this as far as (I think I know) this may efect the sound signature
The TO3P is certanly a bonus
EUVL,
In the simulations you posted, the response of the 2sk1530 looks a lot like that of a tube. Am I looking at this graph incorrectly or from the wrong perspective
In the simulations you posted, the response of the 2sk1530 looks a lot like that of a tube. Am I looking at this graph incorrectly or from the wrong perspective
Tanks Papa
The TO3P is very attractive.
And more current more voltage is certainly good.
But what would be the sound signature?
F5 sound really good and small compromise against above bonuses may be ok.
Why those are not used by Papa Pass is the big question.
Let me guess the answer.😀
Get a few and try...
Next big question
Naughty naughty little Alex want the F6.
Could you please titillate our soldering buds and give as a taste of what it would be like?
Many tanks
Al
With a bunch of lateral MOSFETs on hand, I am going to build a couple of these -- although my Thors don't seem to have any volume deficit running bi-amped with F5's.
Nelson, help! Where the am I supposed to find the JFETs and MOSFETs to build this beautiful beast? It is even difficult to find SPICE models so I can simulate this in my "wet dreams".
Biased with some care, it actually delivers are reasonably smooth transition.
In any case, if you want this kind of current, you will have some mild
transitions unless you want to run 20 amps or more of bias.
😎
The train left the station...but LinearSystems is, hopefully bringing it back....those dreaded high Idss knock-off P-channel switching JFETs aren't necessarily dog-dreck, or you can use GR devices which work well in F5's. The knock-offs are about 20dB noisier. N-channel devices are readily available from Mouser.
...and SPICE models are generally available for the IRF and Fairchild MOSFETs, the JFET models are easily available, and Bob Cordell's book belongs right next to your copy of the Bible as it explains how to make MOSFET models.
Lateral MOSFETs have half the input capacitance of the vertical ones but less than a quarter of the steady state current carrying capacity.
Thanks,
It would seem they're drop-in replacements for the Toshiba JFETS. I was just wondering if they will sound as good the Toshiba since the Toshiba are obsolete and becoming rare. I wonder why Toshiba themselves didn't replace them with something better?
> In any case, if you want this kind of current, you will have some mild transitions unless you want to run 20 amps or more of bias.
I don't mind the transition that much, I do care that it is too close to bias (normal listening).
If I were you I would keep the bias voltage across the R_source at say 0.3V.
That I know the diode won't kick in till I almost leave Class A anyhow.
But why not try 3497/681 ?
Patrick
I don't mind the transition that much, I do care that it is too close to bias (normal listening).
If I were you I would keep the bias voltage across the R_source at say 0.3V.
That I know the diode won't kick in till I almost leave Class A anyhow.
But why not try 3497/681 ?
Patrick
Balanced Rail Voltage Choices - more Class A
NP -
When I built my Balanced Cascoded F5, I chose the lowest rail voltages that had a flat transconductance plateau for the MOSFETs (2SK1530 and 2SJ201 at 16V). I did this so I could crank up the current and have more power in Class A at a given wattage for each output device.
I noticed you were recommending higher rail voltages and paralleling devices for more power, but wouldn't more current help with Class A?
NP -
When I built my Balanced Cascoded F5, I chose the lowest rail voltages that had a flat transconductance plateau for the MOSFETs (2SK1530 and 2SJ201 at 16V). I did this so I could crank up the current and have more power in Class A at a given wattage for each output device.
I noticed you were recommending higher rail voltages and paralleling devices for more power, but wouldn't more current help with Class A?
You could substitute FQP12P20 which is a TO-220 device -- the transconductance is a tiny bit lower and the device has a higher thermal impedance...
Ah, but even at 1S to 1.5S, the power diode trick would save a couple of volts.
With oldy 600mW JFET cans at the entrance, 4 laterals in parallel would be near equivalent.
- Status
- Not open for further replies.