Hi Toni,
Well, actually only for the fun of it. The N-Channel and P-channel doesn't seem to be that complementary so I thought it could be fun trying to see what could be obtained by using N-Channel output stage only.
In reality, any of your designs are more than good enough. But, there is always a new mouse-trapWe will see if and when I get this started.
Cheers,
Mogens
An idea for a quasi complementary N-Channel MOSFET output stage...
Have fun, Toni
Attachments
... but clipping behavior is catastrophic ...
You need to add some diode network, to avoid the strange clipping behaviour.
Sajti
SA2015 quasi complementary N-Channels MOSFETS only
One idea is to switch off upper half MOSFET if output rail is near negative supply. Attached a possible solution.
(Acceptable?) shoot through only when driven with overloaded square wave...
Performance 50W@8R output level better as expected.
BR, Toni
One idea is to switch off upper half MOSFET if output rail is near negative supply. Attached a possible solution.
(Acceptable?) shoot through only when driven with overloaded square wave...
Performance 50W@8R output level better as expected.
BR, Toni
Attachments
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I didn't following the development of the whole circuit, but if You have no place for the diodes, just build it! It was done by Mark Levinson, or by Mackie in the M1400...
Set about 1-2mA bias current over the transistors with R1 and R2, set the zeners to just limit under the limitation of the original circuit.
This is the simple solution, makes hard limit, but you can get even soft slipping if change D3 and D4 with diode+resistor network.
Sajti
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Seems to help a lot!
Simulation THD20k at 30Vrms on 8R load: 0.0018%
Now it's time to build and measure a test sample ...
BR, Toni
Attachments
SA2015 pcb
As can be seen a limited amount of fresh arrived SA2015 rev 1.4 pcb's are available...
Send an email to
sa2015 (at) aws-it.at
if you are interested in DIY building this MOSFET amplifier.
Price for one pcb is nearly my cost price ~ about 9,00 Euro.
Shipping costs are extra and are depending on the distance from Austria to your location.
Quality: FR4, 1.6mm, 2 oz copper, blue mask, white silk, HASL with lead
BR, Toni
As can be seen a limited amount of fresh arrived SA2015 rev 1.4 pcb's are available...
Send an email to
sa2015 (at) aws-it.at
if you are interested in DIY building this MOSFET amplifier.
Price for one pcb is nearly my cost price ~ about 9,00 Euro.
Shipping costs are extra and are depending on the distance from Austria to your location.
Quality: FR4, 1.6mm, 2 oz copper, blue mask, white silk, HASL with lead
BR, Toni
Attachments
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A quick iPhone pic of testing of Toni's SA2014. So far both channels have passed tests with +-30V bench PSU rails. No mistakes so far although I very nearly fried the output Zobel with a little over zealous input voltages. Scope shots of output with 100mVpp input square wave 100kHz and 200kHz respectively (+- 20V bench psu supply).
Tomorrow I will fire up the amp's PSUs for the first time and then couple them up on the bench.
Tomorrow I will fire up the amp's PSUs for the first time and then couple them up on the bench.
Attachments
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