Primarily the input diamond buffers and some small contribution from the TIS - hFE and delta Vbe.
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hFE and Vbe both depend on Tj.
Thermal coupling of thermally matched diamond buffers would probably help with drift of temperature and drift of differential temperature.
Not sure what can be done about TIS. Maybe keeping Tj lower will reduce the warm up drift.
Any further thoughts from yourself?
Thermal coupling of thermally matched diamond buffers would probably help with drift of temperature and drift of differential temperature.
Not sure what can be done about TIS. Maybe keeping Tj lower will reduce the warm up drift.
Any further thoughts from yourself?
It's already low and the thermal coupling would not mske much difference with TO-92 packages.
AC coupling the feedback would almost certainly remove warm up drift, but that would not be acceptable in this design IMV - for started the low gain setting resistor would mean a very large cap.
The drift is due to second order effects - so thermal coupling wont make it go away.
AC coupling the feedback would almost certainly remove warm up drift, but that would not be acceptable in this design IMV - for started the low gain setting resistor would mean a very large cap.
The drift is due to second order effects - so thermal coupling wont make it go away.
Since Bonsai put so much effort to bring us this amazing NX Amp, it is only fair that I start posting some pictures of the final build which I'm doing now.
Here's the Amp module and PSU side by side. I wanted to minimize cable length and optimize it so not too much cabling would show up.
Here's the capacitors I'll be using, the other ones in the above picture was just to test the PSU. I'm configured in a dual mono setup so I will have two PSUs and two transfos or a single transfo with quad secondaries.
BTW, this amplifier sounds really good!
Ciao!
Do
Here's the Amp module and PSU side by side. I wanted to minimize cable length and optimize it so not too much cabling would show up.
Here's the capacitors I'll be using, the other ones in the above picture was just to test the PSU. I'm configured in a dual mono setup so I will have two PSUs and two transfos or a single transfo with quad secondaries.
BTW, this amplifier sounds really good!
Ciao!
Do
Second module mounted! I'm on a roll!!! 😀
I have two 500VA transformers to tuck in the chassis, it will be really tight fit, probably will have to stack them. I did not buy them specifically for this application, I had them on inventory so I'm using them. Should be pretty quiet!
Ciao!
Do
I have two 500VA transformers to tuck in the chassis, it will be really tight fit, probably will have to stack them. I did not buy them specifically for this application, I had them on inventory so I'm using them. Should be pretty quiet!
Ciao!
Do
Here's the chassis shot! I like it a lot and it also does cut down on visible wires which I always try to hide the best I can.
Ciao!
Do
Ciao!
Do
So many great builds..... what suggestions are there to obtaining pre-punched chassis with heat sinks.... best sources are...........?? Mechanicals are my weak spot. I need as much of the mechanicals done for me as possible or I never get it built.
Chassis, heat sinks, punched holes, loaded pcb.... I do the assembly and test well. Not too much of the DIY.
THx-RNMarsh
Chassis, heat sinks, punched holes, loaded pcb.... I do the assembly and test well. Not too much of the DIY.
THx-RNMarsh
DIYaudio offer a range of ready made chassis kits.
All pre-punched, drilled and tapped with all the hardware to assemble.
We occasionally see a report of some missing hardware, but that gets sorted once the problem is reported back to DIYaudio.
All pre-punched, drilled and tapped with all the hardware to assemble.
We occasionally see a report of some missing hardware, but that gets sorted once the problem is reported back to DIYaudio.
Wow Thimios - that's quite a build!
I trust you are happy with the sound, and will get lots of pleasure listening to your sx-Amp (I am listening to mine now -a coustic music via Spotify!)
Thanks for posting your build pics.
Hi Bonsai i wish you a happy new year .
Thanks for sx amp.
I and my son, listening to mine continually from yesterday (always this is in on function, day and night since 30-12-14).
It is a wonderful amplifier.
Best Regards.
Thimios.
Some other photos
Attachments
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Since Bonsai put so much effort to bring us this amazing NX Amp, it is only fair that I start posting some pictures of the final build which I'm doing now.
Here's the Amp module and PSU side by side. I wanted to minimize cable length and optimize it so not too much cabling would show up.
Here's the capacitors I'll be using, the other ones in the above picture was just to test the PSU. I'm configured in a dual mono setup so I will have two PSUs and two transfos or a single transfo with quad secondaries.
BTW, this amplifier sounds really good!
Ciao!
Do
Pinnocchio
Seem like you finish your nx amp. Could you compare it to the first one. I would like to build CFA but don't know which one to build.
Bonsai.. NX question?
L1=0.6uH as per specification..
I wind exactly as prescribed and I get 0.4uH
My meter is very accurate.. should I wind to 0.6uH
What is the tolerance? I suppose some builders are out a little here..
L1=0.6uH as per specification..
I wind exactly as prescribed and I get 0.4uH
My meter is very accurate.. should I wind to 0.6uH
What is the tolerance? I suppose some builders are out a little here..