I cannot read values on 3982 & 4.
Post it bigger.
Give me some starters.
peak output current, peak output voltage. min Vds at maximum output.
device data.
BTW,
I am not an amplifier designer, don't rely on my simplified guesstimating methods.
Post it bigger.
Give me some starters.
peak output current, peak output voltage. min Vds at maximum output.
device data.
BTW,
I am not an amplifier designer, don't rely on my simplified guesstimating methods.
Last edited:
Thanks Andrew your help is appreciated. I have mailed you the needed info, maybe the schematic will be better now. Any assistance is better than what I know. 🙂
I do not know enough about the AC theory to design analogue amplifiers and other analogue circuits.
Compensation is just one area where I know that I lack the knowledge.
There are many other areas
I know enough to recognise that I am not an amplifier designer.
Compensation is just one area where I know that I lack the knowledge.
There are many other areas
I know enough to recognise that I am not an amplifier designer.
Major Life Events
Hello Vrystaat,
Thank you for yourpost "30th June 2013, 06:54 PM". I saw your post by chance, good chance, as this is my first time looking at this thread since 2007.
As a result of a work related injury my life has been a mess since November 2007. Some improvement as of December 2013. I hope I did not loose all the parts I was had gathered to build the amps. I am still having some struggles from the fallout of the injury and a number of challenges that have flowed from since.
I was to the quasi "site" the last few days and for a bit today, but the schematic for the soft start power on link goes to the PCB and the PCB link goes to the PCB. ummmm, looks like I need to find time (do not have yet really) to catch up on much that has transpired in last 7+ years here. The upset of my life was such that I could not even look at the site or this thread I liked so much as I did not know if and when I ever be able to resume my goal of building about 21 of these amps for an active crossover system 5.1 or 7.1 (7.1 again existed back in early 1980's with unique processor of time and still to this day.)
The "journey" has me at a place where it is going to be still a challenge to build, and I have no space even for speakers now. I lost my apartment of 31 years as part of this mess that was a food since and able to handle 5.1 I had long before, early 1980's. I know I saved some of my parts, I just do not know if was able to for all of them.
Now the best store in the city for parts for over 50 years is closing in a couple days so I am struggling with that loss for parts when I need them as a source of so many good parts like caps, small heat sinks, and many others things you just do not find that easy. One of those stores that had everything electronics including the electronic version for the toilet as well as the toilet! This the store I picked up my 44-0-44 1100 VA toroids for $25.00 each.
I hope I can be here again more often soon, but it is still going to take some time. This is one project very near and dear to me I have thought about since my life got flipped to a mess. Many were so helpful before as I worked on finding the parts, some so kind to send me some parts I was having difficulty finding. It hurts in more ways than one. Sorry I better go before I really hurt more.
Again Vrystaat, thanks so much for asking. Very much appreciated.
John L. Males
Toronto, Ontario
Canada
27 September 2015 12:45
27 September 2015 13:12 (typo corrections, learned how to add links in posting text again)
Official Quasi Thread Researcher (Formerly, maybe one day I can resume the work I was doing nobody was aware of to create a guide for the many of this project and then some)
Hello Vrystaat,
Thank you for yourpost "30th June 2013, 06:54 PM". I saw your post by chance, good chance, as this is my first time looking at this thread since 2007.
As a result of a work related injury my life has been a mess since November 2007. Some improvement as of December 2013. I hope I did not loose all the parts I was had gathered to build the amps. I am still having some struggles from the fallout of the injury and a number of challenges that have flowed from since.
I was to the quasi "site" the last few days and for a bit today, but the schematic for the soft start power on link goes to the PCB and the PCB link goes to the PCB. ummmm, looks like I need to find time (do not have yet really) to catch up on much that has transpired in last 7+ years here. The upset of my life was such that I could not even look at the site or this thread I liked so much as I did not know if and when I ever be able to resume my goal of building about 21 of these amps for an active crossover system 5.1 or 7.1 (7.1 again existed back in early 1980's with unique processor of time and still to this day.)
The "journey" has me at a place where it is going to be still a challenge to build, and I have no space even for speakers now. I lost my apartment of 31 years as part of this mess that was a food since and able to handle 5.1 I had long before, early 1980's. I know I saved some of my parts, I just do not know if was able to for all of them.
Now the best store in the city for parts for over 50 years is closing in a couple days so I am struggling with that loss for parts when I need them as a source of so many good parts like caps, small heat sinks, and many others things you just do not find that easy. One of those stores that had everything electronics including the electronic version for the toilet as well as the toilet! This the store I picked up my 44-0-44 1100 VA toroids for $25.00 each.
I hope I can be here again more often soon, but it is still going to take some time. This is one project very near and dear to me I have thought about since my life got flipped to a mess. Many were so helpful before as I worked on finding the parts, some so kind to send me some parts I was having difficulty finding. It hurts in more ways than one. Sorry I better go before I really hurt more.
Again Vrystaat, thanks so much for asking. Very much appreciated.
John L. Males
Toronto, Ontario
Canada
27 September 2015 12:45
27 September 2015 13:12 (typo corrections, learned how to add links in posting text again)
Official Quasi Thread Researcher (Formerly, maybe one day I can resume the work I was doing nobody was aware of to create a guide for the many of this project and then some)
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Can somebody explain one thing, and correct me if I'm wrong:
with +/- 50V rails, power on 8Ohm speaker will be limited to 80-90 Watts, regardless of how many pairs of MOSFETS I use, is that right (assuming 1 pair can deliver 80W, which in case of NMOS200 - it can) ?
Extra pairs are added because of thermal/cooling issues, NOT to increase the power, right?
If we need more power, we have to increase rails voltage, and maybe add extra pairs if we need to extract more power than 1 pair can provide).
I've built two NMOS200 amps with single pairs, they run and sound great; not sure if it make sense to build the same thing with 2 pairs - it's not likely it will get me more watts, will it?
Thanks,
Minek
with +/- 50V rails, power on 8Ohm speaker will be limited to 80-90 Watts, regardless of how many pairs of MOSFETS I use, is that right (assuming 1 pair can deliver 80W, which in case of NMOS200 - it can) ?
Extra pairs are added because of thermal/cooling issues, NOT to increase the power, right?
If we need more power, we have to increase rails voltage, and maybe add extra pairs if we need to extract more power than 1 pair can provide).
I've built two NMOS200 amps with single pairs, they run and sound great; not sure if it make sense to build the same thing with 2 pairs - it's not likely it will get me more watts, will it?
Thanks,
Minek
Yes, supply rail voltage determines maximum output voltage.
mosFET outputs will get around 80 to 90W into 8ohms from +-50Vdc when wired as Source followers. A bit more, ~100W when wired as common Source. BJTs as EF are also ~100W
mosFET outputs will get around 80 to 90W into 8ohms from +-50Vdc when wired as Source followers. A bit more, ~100W when wired as common Source. BJTs as EF are also ~100W
Thanks Andrew.
So how much power I can reasonably squeeze out of 1 pair when increasing voltage?
Say from IRFP260? They can do 200V and dissipate over 200W per one device.
I bet they will die at half of these values, but still, that's a lot of power...
I guess extra pairs are only added because that one pair would run too hot to cool
it efficiently?
Thanks,
Minek
So how much power I can reasonably squeeze out of 1 pair when increasing voltage?
Say from IRFP260? They can do 200V and dissipate over 200W per one device.
I bet they will die at half of these values, but still, that's a lot of power...
I guess extra pairs are only added because that one pair would run too hot to cool
it efficiently?
Thanks,
Minek
The guide for maximum power output of mosFETs is easy.
Find the total output device power rating.
divide by 4.
eg for a 1pr output stage using 200W devices.
Total Power rating = 400W
max output = 100W
Therefore 2pr will be 200W and 3pr will be 300W
Find the total output device power rating.
divide by 4.
eg for a 1pr output stage using 200W devices.
Total Power rating = 400W
max output = 100W
Therefore 2pr will be 200W and 3pr will be 300W
I'll leave the details for the "how-to" for the experts like AndrewT.
Double*, triple, etc**, the number of finals should increase safe current*** output*** by half* again or more**. May have a desirable affect on output impeadence increasing damping factor. Of course to fully realize that*** likely require "more PS."
My $.02, Tony
Double*, triple, etc**, the number of finals should increase safe current*** output*** by half* again or more**. May have a desirable affect on output impeadence increasing damping factor. Of course to fully realize that*** likely require "more PS."
My $.02, Tony
Damping factor?
What damping factor?
http://www.crownaudio.com/media/pdf/amps/damping_factor.pdf
OK, got it.
What damping factor?
http://www.crownaudio.com/media/pdf/amps/damping_factor.pdf
OK, got it.
Here is my finished nmos200, and its board.
IRFPs are mounted using Keratherm Red insulators, all smaller transistors with mica and goo.
Smaller transistors are screwed to the radiator using polyamide screws, that don't melt until 150 degrees Celsius. Easier to isolate them from the heatsink this way.
IRFPs are mounted using Keratherm Red insulators, all smaller transistors with mica and goo.
Smaller transistors are screwed to the radiator using polyamide screws, that don't melt until 150 degrees Celsius. Easier to isolate them from the heatsink this way.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Two more cents - Rod Elliot has designs using MOSFETs & Bi-Polaris on his site.
Both use a single pair of finals rated safe into 8 ohms. Into 4 ohms they're good for between 60%* to ~100%** power increase but that comes w/a price. Either drop the rail voltage from 50V to 42V* or increase the #** of finals**.
Tony
Both use a single pair of finals rated safe into 8 ohms. Into 4 ohms they're good for between 60%* to ~100%** power increase but that comes w/a price. Either drop the rail voltage from 50V to 42V* or increase the #** of finals**.
Tony
https://www.flickr.com/photos/90060286@N03/22621200176/in/dateposted-public/
https://www.flickr.com/photos/90060286@N03/22024544084/in/dateposted-public/
Son has to build his own Chassis. Has got some coloured sound but it is sweet on the ear. Was worth the effort !
https://www.flickr.com/photos/90060286@N03/22024544084/in/dateposted-public/
Son has to build his own Chassis. Has got some coloured sound but it is sweet on the ear. Was worth the effort !
NMOS200
Please upload updated schematic of NMOS with all modifications whosoever have achieved perfection relating to different positive and negative clipping. Also what is the distortion level and slew rate of the amplifier.
Please upload updated schematic of NMOS with all modifications whosoever have achieved perfection relating to different positive and negative clipping. Also what is the distortion level and slew rate of the amplifier.
Hi ,
From a good friend i receive , six PCB for NMOS 200 . I start to plant one of these and in thes evening I finish . Tomorrow I will start to make some tests .🙂
hi
can i get circuit diagram of thise amp