There’s also Aavid 92FG. They’re a bit tricky to source though.
https://www.rapidonline.com/aavid-thermalloy-92fg-heat-sink-to92-brass-36-1-c-w-36-0258
https://www.rapidonline.com/aavid-thermalloy-92fg-heat-sink-to92-brass-36-1-c-w-36-0258
I've just run Mooly's sim with the pos and neg supply rails set to differing voltages ( I used 48V on pos rail, -35V on neg rail). The nominal voltage on the output is still 0V give or take a few uV. What offset do you mean?
Interesting, does it clip symmetrical?
Power out seems very unbalanced, one transistor is working much harder than the other. Output voltage is still symmetrical.
Power out seems very unbalanced, one transistor is working much harder than the other. Output voltage is still symmetrical.
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Clipping will depend on the mix of rails. If you split them all there are four rails. If the output rails are symmetrical and lower then the front end rails (which can be asymmetrical) then the clipping will always be symmetrical as it is limited by the output side.
If the output rails are higher then the front end (not recommended in any amp really) the clipping asymmetry is determined by the front end.
The servo will always correct the output to zero volts DC provided there is enough basic current available in things like the VAS stage and current source.
Plus 6 and minus 8 volt rails for the front end. Perfect.
Clipping with those rails:
If the output rails are higher then the front end (not recommended in any amp really) the clipping asymmetry is determined by the front end.
The servo will always correct the output to zero volts DC provided there is enough basic current available in things like the VAS stage and current source.
Plus 6 and minus 8 volt rails for the front end. Perfect.
Clipping with those rails:
I've never split them like that but I suppose it can have its uses. It should make for good clipping behaviour if the front end is higher than the outputs and it would lead to cooler running for the output stage for a given bias current.
The only time I would do it on an amp like this is to experiment with removing the current source and going back to the old bootstrapped resistor feed for the VAS stage. I bet that could be good sonically but this design would need higher power specced small signal transistors for the VAS as we've been talking about. Something -/+60 for the front end and -/+35 for the outputs could make for a really nice medium power amp.
The only time I would do it on an amp like this is to experiment with removing the current source and going back to the old bootstrapped resistor feed for the VAS stage. I bet that could be good sonically but this design would need higher power specced small signal transistors for the VAS as we've been talking about. Something -/+60 for the front end and -/+35 for the outputs could make for a really nice medium power amp.
This is basic electricity, take an unbalanced split rail and load them with the same resistance, the higher voltage will source more current. It is logical. I won't even argue about that.
Many designers run the driver stage at higher voltage, this is especially true driving Lat Mosfets so that you can drive the output closer to rails. There where many arguments in DIY regarding this in the Goldmund clones from probably 10 years ago. Anyway, this to me is unimportant, let the guy who wants to do it help himself.
If I remember correctly, for CFP output stages the drivers and output devices should be at the same voltage. I've tinkered with this in sims and did find this to be true.
You can see this in Mooly's sims. Only the IPS and VAS are run on higher rails.
Also, I seem to recall that clipping behavior can be adversely affected by higher IPS-VAS rails, depending on the circuit. Some topologies are sensitive to this.
You can see this in Mooly's sims. Only the IPS and VAS are run on higher rails.
Also, I seem to recall that clipping behavior can be adversely affected by higher IPS-VAS rails, depending on the circuit. Some topologies are sensitive to this.
I want the input , LT071 and Q2、 Q3 to be powered separately and use ±45v, and the CFP output use ± 38v。
±45V is double 17V, generated by voltage multiplier，This is the power supply circuit diagram
During the construction process, the -45V measurement was only -40V, which was unbalanced.
It is hoped that the performance of the amplifier will be improved by improving the power supply.
See 1802#
±45V is double 17V, generated by voltage multiplier，This is the power supply circuit diagram
During the construction process, the -45V measurement was only -40V, which was unbalanced.
It is hoped that the performance of the amplifier will be improved by improving the power supply.
See 1802#
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Why complicate an elegant and simple working design. Is there any indication that it would be markebly superior.
PSRR would likely improve. Not sure what else.
Not sure I understand the need for a voltage doubler. Are you trying to power this from the same transformer as the main PSU? If not, it seems overly complicated.
Not sure I understand the need for a voltage doubler. Are you trying to power this from the same transformer as the main PSU? If not, it seems overly complicated.
I am not sure either, if you want to drive the Lateral Mosfets to rail for the extra 4V swing, I suppose it is a valid arguement. But then you may as well use an overall higher voltage transformer with far less trouble.
I agree. Boosting rails to allow the mosfets to swing closer to the rails only makes sense to me when you're running a high bias and the extra few volts helps with dissipation.
I do see the benefit of increased PSRR. But I would approach it a different way.
Now... if the goal here is to tinker with a new idea, I totally get it. This is a hobby after all - do what makes you happy!
I do see the benefit of increased PSRR. But I would approach it a different way.
Now... if the goal here is to tinker with a new idea, I totally get it. This is a hobby after all - do what makes you happy!
I am content I guess, not that I need another amplifier, this was a seemingly interesting and practical thread for a while, but everything goes south when there is nothing positive to contribute after a while, I guess. All threads die in a similar way. So lets start a new one. I suggest a complete integrated amplifier constructed from members working projects with all the adjustable control thingies lights and switches.
What is the proper sequence of wiring the speaker output?
1. Amp board - Inductor Coil - Speaker Protection - Speaker Terminals
2. Amp board - Speaker Protection - Inductor Coil - Speaker Terminals
I noticed Vunce and others did it number 1 way and GeoffW1 did it number 2 way. Using GeoffW1 speaker protection board if it matters. Maybe it doesnt matter
1. Amp board - Inductor Coil - Speaker Protection - Speaker Terminals
2. Amp board - Speaker Protection - Inductor Coil - Speaker Terminals
I noticed Vunce and others did it number 1 way and GeoffW1 did it number 2 way. Using GeoffW1 speaker protection board if it matters. Maybe it doesnt matter
I think your answer is in your last sentence. As you pointed out, my amp is wired as per option 2. Its currently in use pretty well daily for long periods of time with no problems. Vunce and others have theirs in option1 and I don't hear any cries of woe from them about failures or poor sonics. I don't believe electrically there's any difference.