thats a very good looking setup IDEFIXES but dont you think that your heat sink is way too much? does NMOS200 really required heatsink that big?but nice amp really.🙂
Yes it's overkill for NMOS200 but as i said previously, i don't pay for those heatsink, they are coming from industrial rubbish where i found 9 of them. They visualy a little bit damage but whith a little work on them and little bit paint they are good for diy project.
Marc
hi quasi...
I have build the nmos 200 with a +-25V rails and adjust some resistors values to suit up tha current feeds. It's a good amp but i need a more powerful version of the amp like the Nmos350 but my problem is the trafo that i have has a single secondary winding at 100vac, 1000VA.
So,how can we modify the nmos 350 to run on a single rail voltage of 140(just like +-70v) and put a output coupling capacitor. I am no designer just a builder.. your help is highly appreciated...
I have build the nmos 200 with a +-25V rails and adjust some resistors values to suit up tha current feeds. It's a good amp but i need a more powerful version of the amp like the Nmos350 but my problem is the trafo that i have has a single secondary winding at 100vac, 1000VA.
So,how can we modify the nmos 350 to run on a single rail voltage of 140(just like +-70v) and put a output coupling capacitor. I am no designer just a builder.. your help is highly appreciated...
My NMOS200
my NMOS200 is working without any problem, initial test indicate that amp is in good condition from offset voltage to idle current, audio is clear with input from a cd player without preamp or tone control, I used +- 50 volts on it,I will soon build the 2nd channel , my NMOS 350 is having a problem with idle current adjustment, my plan to change all mosfet with 2sk1530 instead of using the irfp450 just like what I used with my NMOS 200, attached is the picture of initial test.
my NMOS200 is working without any problem, initial test indicate that amp is in good condition from offset voltage to idle current, audio is clear with input from a cd player without preamp or tone control, I used +- 50 volts on it,I will soon build the 2nd channel , my NMOS 350 is having a problem with idle current adjustment, my plan to change all mosfet with 2sk1530 instead of using the irfp450 just like what I used with my NMOS 200, attached is the picture of initial test.
Attachments
3,264px × 2,448px (scaled to 1,123px × 842px)
according to my screen this schematic is legible after it is rescaled.
Why post that enormous pic? 6times as many pixels takes six times as long to download.
according to my screen this schematic is legible after it is rescaled.
Why post that enormous pic? 6times as many pixels takes six times as long to download.
Image fixed.
Some progress on my Nmos200.
I need to install RCA socket and screw rear and frant to main structure.
I need to install RCA socket and screw rear and frant to main structure.
Sorry for my english, i am from Russia. Can i use this circuit, or exist better?
An externally hosted image should be here but it was not working when we last tested it.
hi SaMaHa
this is the final sch you can check this on his site
http://sites.google.com/site/quasisdiyaudiosite/home
regards
ravs
be a vegeterian........
Ha-ha, yes, i am from KGB.
On yours that who from Russia that KGB? How to place drawing?
Second attempt:
RapidShare: 1-CLICK Web hosting - Easy Filehosting
On yours that who from Russia that KGB? How to place drawing?
Second attempt:
RapidShare: 1-CLICK Web hosting - Easy Filehosting
Nmos350 Mk2 mod
Hi everybody!
It’s my first post here. Don’t shoot to me…
I modified Quasi’s Nmos350 Mk2 scheme and made PCB for this mod.
Here it’s.
I use small 0,6 W metal film resistors. Bipolar transistors are the same like on original scheme (I have usable only BD139/140 in my EAGLE library) except T9 – there is BD139 (TO126) and MOSFET transistors are IRF640. JP1 is there because I wont to try an additionally power supply like Upupa Epops in his great MOSFET amplifiers DPA3XX (post #164).
What’s yours opinion? Is this PCB correct (ground and component location...)?
Thanks.
Hi everybody!
It’s my first post here. Don’t shoot to me…
I modified Quasi’s Nmos350 Mk2 scheme and made PCB for this mod.
Here it’s.
I use small 0,6 W metal film resistors. Bipolar transistors are the same like on original scheme (I have usable only BD139/140 in my EAGLE library) except T9 – there is BD139 (TO126) and MOSFET transistors are IRF640. JP1 is there because I wont to try an additionally power supply like Upupa Epops in his great MOSFET amplifiers DPA3XX (post #164).
What’s yours opinion? Is this PCB correct (ground and component location...)?
Thanks.
Attachments
Hello
The almost the same schematic has Pioneer A-9 (the new one that has USB DAC), except input transistors. They are field type, or so on. Wonna say that the guy who own it really disappointed by the sound =) But it is only my opinion.
Regards
The almost the same schematic has Pioneer A-9 (the new one that has USB DAC), except input transistors. They are field type, or so on. Wonna say that the guy who own it really disappointed by the sound =) But it is only my opinion.
Regards