A long overdue progress update.
I went with the Jan Didden TReg for my b+ supply.
I made a motherboard to accommodate the raw b+, the TReg board and the heater regulator section.
Having acquired a variac. I finally got to testing the power supplies over the last couple of evenings.
After trimming, the b+ is rock solid on 265vdc. The heaters are rock solid at 12.7vdc. No excessive heat from the heatsinks under load.
Not quite ideal on the heater voltage but I don't think 0.7% out is much to worry about. IIRC, datasheets typically specify +/-10%.
I also found an error on the silkscreen/bom. The resistor values used were the values that Broskie recommends for a headphone amp. So I changed the 4 or so resistors on each board to the slightly more optimal values for a lifestage. I don't think the difference would have been noticeable. But I had the resistors on hand so I figured why not?
Now that the power supply boards are tested and working. I can finally rig up a proper test of the smp boards.
It will probably take me a couple of weeks. I will rig up a basic setup in a scrap chassis and commence the next round of testing.
I went with the Jan Didden TReg for my b+ supply.
I made a motherboard to accommodate the raw b+, the TReg board and the heater regulator section.
Having acquired a variac. I finally got to testing the power supplies over the last couple of evenings.
After trimming, the b+ is rock solid on 265vdc. The heaters are rock solid at 12.7vdc. No excessive heat from the heatsinks under load.
Not quite ideal on the heater voltage but I don't think 0.7% out is much to worry about. IIRC, datasheets typically specify +/-10%.
I also found an error on the silkscreen/bom. The resistor values used were the values that Broskie recommends for a headphone amp. So I changed the 4 or so resistors on each board to the slightly more optimal values for a lifestage. I don't think the difference would have been noticeable. But I had the resistors on hand so I figured why not?
Now that the power supply boards are tested and working. I can finally rig up a proper test of the smp boards.
It will probably take me a couple of weeks. I will rig up a basic setup in a scrap chassis and commence the next round of testing.
Here's a mockup of what I'm going to do.
My test chassis will be an old Harman kardon receiver chassis because it's convenient and big enough.
A bit of metal working to cut a hole for the IEC socket and power switch.
Otherwise I just need to drill a bunch of mounting holes.
Volume pot and source selection will be on shift extensions.
Whack in a few rca sockets and then it's just wiring.
My test chassis will be an old Harman kardon receiver chassis because it's convenient and big enough.
A bit of metal working to cut a hole for the IEC socket and power switch.
Otherwise I just need to drill a bunch of mounting holes.
Volume pot and source selection will be on shift extensions.
Whack in a few rca sockets and then it's just wiring.