I did some changes in quasis design with additional devices but not tested...
Nmos with Class B output stage, reduces Heat and increase efficiency
T10 and T14 with additional devices is VI Limiter and short circuit protection.
BC560/2SC1845 is changed to MPSA42 and 92 because impossibile to get by local supplier, another option is Toshiba 2SA970/2 SC2240 available by local supplier, IRFP 460 is cheap and easy to get
Rail: +/-80 V
Could this work ?
Nmos with Class B output stage, reduces Heat and increase efficiency
T10 and T14 with additional devices is VI Limiter and short circuit protection.
BC560/2SC1845 is changed to MPSA42 and 92 because impossibile to get by local supplier, another option is Toshiba 2SA970/2 SC2240 available by local supplier, IRFP 460 is cheap and easy to get
Rail: +/-80 V
Could this work ?
quasi said:
Quasi, it is not yet correct. It seems like you posted the old schematic. You could also correct the -ve connection of C5 from Gnd to -vee.
Quasi,
I like it. It's a fine amplifier, solid as hell.
Congratulations!
Have a great year, hope the 44C weather is treating you OK.
Cheers,
Hugh
I like it. It's a fine amplifier, solid as hell.
Congratulations!
Have a great year, hope the 44C weather is treating you OK.
Cheers,
Hugh
Hello,
@ quasi,...thanks for your great project and share experience
I have add your last improvents in modified NMOS with Class B Output Stage + VI/CLIP limiter and Short circuit protection, could this features work stable ?
how does NMOS sounding compare to BJT amplifiers ?
I dont have build nmos since today but want do it the next time with this additional features
regards
@ quasi,...thanks for your great project and share experience
I have add your last improvents in modified NMOS with Class B Output Stage + VI/CLIP limiter and Short circuit protection, could this features work stable ?
how does NMOS sounding compare to BJT amplifiers ?
I dont have build nmos since today but want do it the next time with this additional features
regards
power amplifier under devlopment
hi qsa
greetings what would its power output be in 4 ohms can
limiter circuit below power amp circuit be used for other amplifiers
thanking you
andrew lebon
hi qsa
greetings what would its power output be in 4 ohms can
limiter circuit below power amp circuit be used for other amplifiers
thanking you
andrew lebon
@andrew lebon
This design is for 80 V +/- but not tested, actually I prepare sample PCB,
output power should be about 600 W RMS @ 4 OHM
I have add CLIP/Short VI limiter circuit + Class B Output Stage in nmos design from PA Amplifier with similar output power
The Benefit for Class AB + B Output Stage compare to Class AB is more effiency and and a lot of less heat
below left in schematic is DC detect and turn on delay from quasi for 24 V DC, below right is from PA Amplifier and need 15 V DC
For high output Power we need +/-130 V Rail, more mosfets, small changes in design and can get about 1500 W RMS @ 4 OHM
I want share and add my ideas for constructive and destructive critics to improve nmos design
Waiting for replys....
This design is for 80 V +/- but not tested, actually I prepare sample PCB,
output power should be about 600 W RMS @ 4 OHM
I have add CLIP/Short VI limiter circuit + Class B Output Stage in nmos design from PA Amplifier with similar output power
The Benefit for Class AB + B Output Stage compare to Class AB is more effiency and and a lot of less heat
below left in schematic is DC detect and turn on delay from quasi for 24 V DC, below right is from PA Amplifier and need 15 V DC
For high output Power we need +/-130 V Rail, more mosfets, small changes in design and can get about 1500 W RMS @ 4 OHM
I want share and add my ideas for constructive and destructive critics to improve nmos design
Waiting for replys....
power amplifier under development
hi qsa
greetings thanks for the reply circuit looks interesting any pcb
pattern any replacement transistor for 2sd669 waiting to try it the
gut feeling is will sound great bye
thanking you
andrew lebon
hi qsa
greetings thanks for the reply circuit looks interesting any pcb
pattern any replacement transistor for 2sd669 waiting to try it the
gut feeling is will sound great bye
thanking you
andrew lebon
AKSA said:
Hi Mate,
Yes this weather is passed the "enough is enough" stage. It's been over 40 for more than a week and we even had a 45.9 a few days ago. Of course this is temperature in the shade, probably a few degrees warmer when moving about. And I can't remember when it rained last. I think South Australia (Australia?) has got a few ecological problems at the moment. Coupled with a confused state government, the outlook is quite bleak.
The main purpose of the design changes is to increase the speed and linearity of the second stage and to add better control and symmetry to clipping. I've also adopted recent discussions about the ccs for the first and second stages.
Nice to hear from you again Hugh, I hope things are better in Vic.
Cheers
Q
Hi Quasi,
Minor question :
How thick is the material for the 'U' channel that you used? and what are the measurements (I mean how wide is the outside of the 'U'). The height and length are arbitrary for they can be adjusted but the width can affect its mounting holes. I am doing pcb for the nmos350 and the U channel may be useful for other projects of mine too. 2 (or more) for the price of 1. So just want to make sure what I am looking for before I start doing so.
Minor question :
How thick is the material for the 'U' channel that you used? and what are the measurements (I mean how wide is the outside of the 'U'). The height and length are arbitrary for they can be adjusted but the width can affect its mounting holes. I am doing pcb for the nmos350 and the U channel may be useful for other projects of mine too. 2 (or more) for the price of 1. So just want to make sure what I am looking for before I start doing so.
Hi Bigpanda,
The U-channel is 12mm wide. The uprights on the length I have are about 2mm thick.
Cheers
Q
The U-channel is 12mm wide. The uprights on the length I have are about 2mm thick.
Cheers
Q
Quasi,
Thanks for the info. mmmm... 2mm seems to be too thin for working as bracket for output transistors.
Thanks for the info. mmmm... 2mm seems to be too thin for working as bracket for output transistors.
bigpanda said:
No man, I was talking about the 2nd and 3rd stage heatsink for the Nmos350. 2mm would be too thin for an output stage bracket for sure.
Cheers
Q
Sorry Quasi,
I know the U channel is for 2nd and 3rd stage. I was planning it for another project that use it for output trans. I guess I just have to find something thicker, I guess 4mm should be good enough.
Thanks
I know the U channel is for 2nd and 3rd stage. I was planning it for another project that use it for output trans. I guess I just have to find something thicker, I guess 4mm should be good enough.
Thanks