I'm developing a little power supply for my amp using Nelson's ideas with FET regulation. What I discovered, at least in the world of Sim, is that you can reverse phases on a center-tap transformer and cancel some of the unwanted noise in the power supply. Here's what I did:
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Magura said:Hmm, we can't have you talking to yourself all the time
So, have you actually built the amp?
Magura
Hahahahaaaaaa......... I do that a lot!
I'm in the process of gathering parts. I have most of them.
It's fun playing with the sim, but the time has come to make my boy's lab pay for itself.Happy holidays, Magura. Give the misses a hug from me as well--imagine having a mate sweet enough to play with your inductors on a cold winter evening.......chills.
I've finished designing the power supply...
but in the meantime:
I had my sweet "golden ears" wife give my amp a listen. I tried different voltages and pointed to the LU1014D performance graph--as if one look would explain everything.
She looked at me as if I'd been couped up in my lab too long.
Her conclusion is as follows: Higher voltage/lower amperage = clear, brilliant high notes with a narrowness in ambiance. Lower voltage/proper amperage = warmer sound, smoother. Overall, warm and smooth gets the nod.
She does like the sound, but four volts leaves room for precious little output signal.
I could always explore, perhaps discover a way to lower the source resistance...
For the moment--tweaking is a favorite pastime--I discovered that the secondaries on my Plitrons are 0.1 ohm and have 30mH inductance. 30mH is a far cry from 225mH, but what the hell.
Why not give it a try.
Ok, bottom end is weaker--to be expected--but the mids and highs are so lush, and this is a 500hz to 20K amp for my sound system, yes?
I bravely bumped the variac dial upwards...
No smoke...phew.
I ended the adventure with 5.88 volts out of the power supply which gave me 4 volts across the Jfet's drain/source. I have 0.53 volts across the transformer (per leg). With 0.1 ohms resistance I figure I've got roughly 5.3 amps available per leg... times 4 volts drain/source gives me 21.2 watts through the Jfet. Forgive me, dear Nelson...
until she blows.... I'll keep you guys posted.
but in the meantime:
I had my sweet "golden ears" wife give my amp a listen. I tried different voltages and pointed to the LU1014D performance graph--as if one look would explain everything.
She looked at me as if I'd been couped up in my lab too long.
Her conclusion is as follows: Higher voltage/lower amperage = clear, brilliant high notes with a narrowness in ambiance. Lower voltage/proper amperage = warmer sound, smoother. Overall, warm and smooth gets the nod.
She does like the sound, but four volts leaves room for precious little output signal.
I could always explore, perhaps discover a way to lower the source resistance...
For the moment--tweaking is a favorite pastime--I discovered that the secondaries on my Plitrons are 0.1 ohm and have 30mH inductance. 30mH is a far cry from 225mH, but what the hell.
Why not give it a try.
Ok, bottom end is weaker--to be expected--but the mids and highs are so lush, and this is a 500hz to 20K amp for my sound system, yes?
I bravely bumped the variac dial upwards...
No smoke...phew.
I ended the adventure with 5.88 volts out of the power supply which gave me 4 volts across the Jfet's drain/source. I have 0.53 volts across the transformer (per leg). With 0.1 ohms resistance I figure I've got roughly 5.3 amps available per leg... times 4 volts drain/source gives me 21.2 watts through the Jfet. Forgive me, dear Nelson...
until she blows.... I'll keep you guys posted.
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