Original FW products use one Antek 300VA psu transformer with two secondaires for 25 watt's stereo amplifiers
so I think Your ~ 10 watt's Vfet can do as well . My
Great Your are not in hurry to start build them today , patience Mr. Pass in the near future do design something Watt's New
: power stage(s) and super front end(s) for the single Sony Vfet amplifiers. Me look at on the FW radar every day
it's been a while i have not looked at amplifier anymore, focus on room treatment and speaker build. maybe 4 class a in my home should stop me because i can only use 1 at a time, even this situation forced to build 2nd speaker set 😀
i consider super front end will be ZM iron pre with jfet front end but the price is not my budget friendly
i consider super front end will be ZM iron pre with jfet front end but the price is not my budget friendly
knows what the cool Diyer friendly FE is for the SE Vfet , then Greedy Boyz can enjoy " the every last drop of the juicy music "Vfet Part 3
😀
that's having more sense 🙂
I know that prices are not too friendly,explanation is so simple - drekload of man-hours invested in each one.....
on the other hand , I'm not just proud of excuisite results overall,but also of excuisite bang for the buck -ratio....miles above anything on the market
I know that prices are not too friendly,explanation is so simple - drekload of man-hours invested in each one.....
on the other hand , I'm not just proud of excuisite results overall,but also of excuisite bang for the buck -ratio....miles above anything on the market
i know it 😀
my attention was caught by slagle avc but looking at tiny iron stopped me, i know your metglass is much more expensive and better
i just have too many items on my list, I consider your turtle on last row by sorting the prices 🙂
my attention was caught by slagle avc but looking at tiny iron stopped me, i know your metglass is much more expensive and better
i just have too many items on my list, I consider your turtle on last row by sorting the prices 🙂
There is also cobalt nanocrystalline and finemet, I know Pieter Treurniet of Tribute raved about it. 😀
with so small cores there can't be so dramatic difference in price - speaking of Slagle high-nickel core and Turtle Metglass
however , for same size core - Finemet is 4 times costlier than Metglass.....
however, best not to clutter this thread with I.P. ........ as I already wrote - I would be more than happy to help any Greedy Boy to make his own iteration - all you need is cheapest AVC on market , decent switches, few JFets and Good Gemini shunt reg - simple enough to make it on veroboard ....... yes , as with any reg - routing is tricky but we are here exactly to solve these tricks together
🙂
however , for same size core - Finemet is 4 times costlier than Metglass.....
however, best not to clutter this thread with I.P. ........ as I already wrote - I would be more than happy to help any Greedy Boy to make his own iteration - all you need is cheapest AVC on market , decent switches, few JFets and Good Gemini shunt reg - simple enough to make it on veroboard ....... yes , as with any reg - routing is tricky but we are here exactly to solve these tricks together
🙂
Advantage...hm. I believe that with the given architecture - involving screw terminal caps, point-to-point wiring, voltage regulators and significant distances between building blocks - it is actually easier to implement star grounding. And with quiescent currents of up to 3A, I'd rather have a separate current return path for each PSU cap.
Almost done 🙂
Almost done 🙂
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Alright, I finished the amp tonight and fired it up. Biasing went without a hitch, no smoke, no drama. Or so I thought. After hooking up some headphones I discovered that there's an awful lot of hum/buzz present. The scope showed a similar picture.
I'm suspecting the ground layout really. Currently all grounds meet at the star ground. I think I'll try and have the signal grounds and the bias supply ground meet at the VFET, and route it to the star ground from there.
Once I get the amp working quietly I'll pull some numbers from the circuit and mess around with finding the sweet spot.
I'm suspecting the ground layout really. Currently all grounds meet at the star ground. I think I'll try and have the signal grounds and the bias supply ground meet at the VFET, and route it to the star ground from there.
Once I get the amp working quietly I'll pull some numbers from the circuit and mess around with finding the sweet spot.
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Those light bulbs are awfully close to the V-Fets. Could they be inducing your hum/buzz?
Rush
also, might be helpful to have two star grounds... main one for PSU at chassis, and another star as floating amp circuit(s) ground, connected to PSU ground with/series a CL-60 thermistor. The resistance of the thermistor helps block any loops.
I did some light probing, and it looks like the output is mirroring whatever is coming out of the bias supply, and that ain't clean DC. At least I think I know where to start cleaning up.
I couldn't get the negative supply generator to work like intended, so I'm converting it to a proper negative bias supply with a dedicated transformer. I have this small-ish 12VA 40Vac (230V primary) transformer that I'll be running off the 44Vac secondary of the main transformer, which should give me something like 11Vac or about -14Vdc to work with. I have also found a cozy place for the little fella:
