To emulate valve gear by using solid state technologies has not reach it´s goal in my opinion. The power amp in this clip is a Matrix Class AB one with SMPS but I think the front end is responsible for some consideration on my part.
Testing Out the Matrix NL12 Light Weight Cab - YouTube
Testing Out the Matrix NL12 Light Weight Cab - YouTube
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Sorry but no.
Grid rectification clamps the positive half cycle , check that the grid-cathode diode has the cathode directly connected or pointing to ground, while the negative half is unclamped.
The grid coupling cap averages that now unsymmetrical signal that into a negative voltage.
Besides, it can both be :
* seen : the output sinewave "kinks" at 0V (or zero crossing) showing the same shape as a cold (too negative) bias and
* measured: out of curiosity I connected a 1M resistor to the grid (as a separator) and a .1uF cap to ground on the other end.
When idle you measure roughly -bias voltage (the high value 1M resistor causes some loss) which gets more negative when you overdrive the amp.
Those mods which add a Zener and some extra parts to avoid that, are missing the point, in my view of course.
See Jadis... and others.
If all that ever happened is that tubes turned off, you'd not see tubes that cherry out, and not from parasitics. Perhaps we are talking about a somewhat different phenomenon, different name, taking place in the same area?
_-_-
If all that ever happened is that tubes turned off, you'd not see tubes that cherry out, and not from parasitics. Perhaps we are talking about a somewhat different phenomenon, different name, taking place in the same area?
_-_-
The MG transitors are used in this Elektor amp.
Now in Hearing Range: Elektor Q-Watt Audio Power Amplifier - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement
Now in Hearing Range: Elektor Q-Watt Audio Power Amplifier - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement
Free download as well
Q-Watt Audio Power Amplifier - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement
I thought that they should have laid it out for 2 pairs since the LME49811 can go up to +/- 100V rails.
Q-Watt Audio Power Amplifier - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement
I thought that they should have laid it out for 2 pairs since the LME49811 can go up to +/- 100V rails.
Just stumbled onto this thread and I have to ask, did anyone look at the data sheet?
For MG9413K this is what I read off the SOA Figure:
30V * 9A = 270W
50V * 5A = 250W
100 * 2.7A = 270W
These are not in any way 400W devices.
One member here posted that they would do 8A at 100V for 100 ms, NO that is the 10mS figure.
Given the thermal resistance I'm going to guess that they beat their spec, but the spec
does not support the claim of 400W.
Are these still available?
For MG9413K this is what I read off the SOA Figure:
30V * 9A = 270W
50V * 5A = 250W
100 * 2.7A = 270W
These are not in any way 400W devices.
One member here posted that they would do 8A at 100V for 100 ms, NO that is the 10mS figure.
Given the thermal resistance I'm going to guess that they beat their spec, but the spec
does not support the claim of 400W.
Are these still available?
Hey Pete,
I briefly glanced at the datasheet. I do not know how they can make that claim either. I did not do the math as you did.
I see that they seem to be available
Semelab - MG9413 - Transistor Audio PNP 260V/30A/400W TO264 - Allied Electronics
newark shows the MAG9412W but not the complement
If you do your analysis criteria, neither does a Onsemi MJW3281 meet its 200W rating with the 100ms or 1 Second curve.
I briefly glanced at the datasheet. I do not know how they can make that claim either. I did not do the math as you did.
I see that they seem to be available
Semelab - MG9413 - Transistor Audio PNP 260V/30A/400W TO264 - Allied Electronics
newark shows the MAG9412W but not the complement
If you do your analysis criteria, neither does a Onsemi MJW3281 meet its 200W rating with the 100ms or 1 Second curve.
Are you saying that they have to use a pulsed test to meet the MJW3281 spec? 1 sec is pretty good
sure DC would be better.
But if you follow the 15A flat part it does go out to about 13.3V making 200W, then also at
50V it does 4A also for 200W which is the end of the constant power slope, then SOA
issues take over and they are less than 200W. This is pretty normal.
I'm not sure why or when they went to a 1 sec test but not all their parts are rated this way.
Thanks for the tip about Allied. I might consider these in TO3 but not finding any.
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