Maybe a linear regulator instead of a shunt?
Goldmund's was very much simpler, but they did increase the voltage to those stages.
Goldmund's was very much simpler, but they did increase the voltage to those stages.
Yes, Goldmund has separated power rails and front-end's rail.
Try to use series regulator for front-end like capacitance multiplier.
Try to use series regulator for front-end like capacitance multiplier.
Maybe something like the kmult from kean........ http://www.diyaudio.com/forums/power-supplies/177516-keantokens-cfp-cap-multiplier-33.html
Not to lose much time over this, but on this paper there are some effective and simple regulators, which control noise quite well.
https://www.google.com.br/url?sa=t&...b2D7vPaDxO8A4CGUBDJMeg&bvm=bv.136593572,d.Y2I
https://www.google.com.br/url?sa=t&...b2D7vPaDxO8A4CGUBDJMeg&bvm=bv.136593572,d.Y2I
If you are interested in increasing feedback then you are losing a lot of gain to Early effect and B-C leakage of the VAS transistors. At the same time it is quite possibly this distortion source that gives the Goldmund and other similar amps their specific colorations, so changing it might be counterproductive if that was what you are after.
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Well in reality I would like to minimize feedback and stay with enough gain so I could drive this amp with a passive preamp.
As for colourations I would like to avoid them.
I am searching for a powerfull machine able to drive 4ohm speakers (and less) providing full bass very detailed but retaining a very fluid trebble.
Please have a look at my latest sch and redo what should be altered....
As for colourations I would like to avoid them.
I am searching for a powerfull machine able to drive 4ohm speakers (and less) providing full bass very detailed but retaining a very fluid trebble.
Please have a look at my latest sch and redo what should be altered....
I can say what may be causing measurable distortions, but I can't say what may be causing coloration. This is an uncomfortable situation because that means the only way to figure that out is to build it and test it. To be honest I think you will get the best results if you immediately build a reasonably stable prototype, because making so many changes in the simulator without hearing the difference leaves you with little actual experience to guide your choices. Even if that means making fewer changes and slower progress, there is at least a good chance you will end up with something you really like. A working prototype is worth a hundred simulations (I have thousands of simulations, not enough prototypes!).
My computer is still dead so I can't open the schematic. Can you post a bigger schematic?
My computer is still dead so I can't open the schematic. Can you post a bigger schematic?
I do intend to build it but I would really appreciate your comments on the schematic for the main amp....
Now I am trying to implement the kmult on both rails but am experiencing difficulties setting the symmetric voltages because both rails seem to be drawing different currents...
Now I am trying to implement the kmult on both rails but am experiencing difficulties setting the symmetric voltages because both rails seem to be drawing different currents...
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Two things:
1) If your regulate the voltages, then different currents will not be a problem.
2) There's a Luxman design from the '80s. model 5M20, which still has a fantastic sound. The stages of your amp follows the Luxman's quite a lot, even if the output stage is bipolar. Low current stages regulated to +/- 67v, and the high current stages have separate secondaries, unregulated, +/- 61v.
1) If your regulate the voltages, then different currents will not be a problem.
2) There's a Luxman design from the '80s. model 5M20, which still has a fantastic sound. The stages of your amp follows the Luxman's quite a lot, even if the output stage is bipolar. Low current stages regulated to +/- 67v, and the high current stages have separate secondaries, unregulated, +/- 61v.
in this case I am not regulating the IPS rail voltages because the Kmult is more like a special cap multiplier.
I use 45vac secondaries followed bz a voltage doubler .... then I reduce voltage with a CRC .... This R must be different in the positive and negative rails due to differences in current pull.
After that I have the kmult smoothers.
I use 45vac secondaries followed bz a voltage doubler .... then I reduce voltage with a CRC .... This R must be different in the positive and negative rails due to differences in current pull.
After that I have the kmult smoothers.
now I added the luxman style reg before the kmult and it seems to work.
I am wondering if I can use the same secondaries to power the input and output stages without loop issues...
I am wondering if I can use the same secondaries to power the input and output stages without loop issues...
You will not have any problems, as long as it all connects to the same star ground.
Nelson Pass used a doubler on his A75 class A power amp, same secondaries, followed by a Kit Ryan discrete regulator.
I suggested the Luxman because a prestigious amp used that reg on an expensive commercial product.
IMHO you can go simpler than that and use a chip regulated supply, just protecting it for higher voltages with a zener.
Nelson Pass used a doubler on his A75 class A power amp, same secondaries, followed by a Kit Ryan discrete regulator.
I suggested the Luxman because a prestigious amp used that reg on an expensive commercial product.
IMHO you can go simpler than that and use a chip regulated supply, just protecting it for higher voltages with a zener.
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