sub-chassis is necessary because the housing's of rigidity and assembly power supply. Also, it is implemented because used components are available for fix or upgrade.
You have probably thought about "white capacitors". They are not electrolytes already they are motor-run 50uF capacitors.
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As I previously said, when I grow up I wanna be Zocky 🙄
Engineering precise, smooth, beautiful, precise 😎
Engineering precise, smooth, beautiful, precise 😎
Thanks. This is my build. Problems before were in someone else's build. Although I helped cause a problem with p2, it did weed out other existing issues.
I call that breaking even cosmicly. 😀😀
I'm not afraid of breaking my amps. Not happy when I break someone else's gear.
I call that breaking even cosmicly. 😀😀
I'm not afraid of breaking my amps. Not happy when I break someone else's gear.
Aleph J in new chassis
Because I like the Aleph J much and it deserved to be biased higher, I made a new chassis. Old chassis was a standard 3U 300mm.
It uses 4 x 0.4K/W heatsinks, which can handle the heat of the Aleph J when the MOSFETs are biased around 30 Watt each.
I removed R27: the 68k2 and the 100k trimpot. so they are fully biased now around total of 2.5 Ampere class A 🙂
Also upgraded some components, MPC74 source resistors, 1837 type 100nF bypass of the 220uF and new better European NTC's in series in the softstart.
The originals blew in my F5T build.
For the power supply I used the BYW99-200 diodes from Jacco 😀, boards from Teabag and Nichicons in the last row of the PSU.
Next is to design a nice front plate and top plate.
I'm listening to it now and it is a good overall amplifier, but at this moment I like my CSX-1 Sony VFET the most... maybe Aleph J needs some more hours of burn in.
Next amp is again with Sony VFETs, if Pa publishes new article with a matched pair in output stage 😀
Because I like the Aleph J much and it deserved to be biased higher, I made a new chassis. Old chassis was a standard 3U 300mm.
It uses 4 x 0.4K/W heatsinks, which can handle the heat of the Aleph J when the MOSFETs are biased around 30 Watt each.
I removed R27: the 68k2 and the 100k trimpot. so they are fully biased now around total of 2.5 Ampere class A 🙂
Also upgraded some components, MPC74 source resistors, 1837 type 100nF bypass of the 220uF and new better European NTC's in series in the softstart.
The originals blew in my F5T build.
For the power supply I used the BYW99-200 diodes from Jacco 😀, boards from Teabag and Nichicons in the last row of the PSU.
Next is to design a nice front plate and top plate.
I'm listening to it now and it is a good overall amplifier, but at this moment I like my CSX-1 Sony VFET the most... maybe Aleph J needs some more hours of burn in.
Next amp is again with Sony VFETs, if Pa publishes new article with a matched pair in output stage 😀
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Congratulation WalterW!!! 
Another stunning outcome!!! Now I am really curious to see the final result with the front panel 🙂
All the Best,
Enrico
Another stunning outcome!!! Now I am really curious to see the final result with the front panel 🙂
All the Best,
Enrico
just be sure to not make any sort of short between two Donuts central screws
I pressume they're on chassis bottom - non isolated- and I see red pcb on some sort of platform
I pressume they're on chassis bottom - non isolated- and I see red pcb on some sort of platform
You are right, haven't really thought about that..... but there is around 5mm between the donut metal plates and the aluminum platform.
It gives no sparks during start-up 😀
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Walter:
Beautiful work, as usual. In fact, it's insanely well organized and neat. Is your therapist concerned about your OCD?
Regards,
Scott
Beautiful work, as usual. In fact, it's insanely well organized and neat. Is your therapist concerned about your OCD?
Regards,
Scott
buy two adequate sized Rotring radierer gummi , and glue them in between Donuts and platform
ya know how gummi is important for safety ....
