I did put a jumper on, but that’s one of those things that are hard to confirm deep in the case. I’m trying to remember if I waited the 20s in case the jumper is not actually closing the contacts. I will try some bright light, and try again, waiting more time for the relay to release. I know it was on long enough to adjust the OS trimmers, without hearing the relay click.
Remove board from chassis, disconnect all wires from all Euroblox. Install jumper in 5 second slot. Clean back side of PCB with alcohol as written on schematic. Connect to lab power supply (+36V, GND). Or MacGyver a way to get (+36V, GND) from your meanwell brick to the Tuba board.
Check the MOSFET gate voltage. Does it ever go high enough to turn MOSFET on? Does it ever go low enough to turn MOSFET off?
Listen for relay click.
Be creative, be resourceful, be thorough. As Christian Soriano from Project Runway advised, be fierce.
Check the MOSFET gate voltage. Does it ever go high enough to turn MOSFET on? Does it ever go low enough to turn MOSFET off?
Listen for relay click.
Be creative, be resourceful, be thorough. As Christian Soriano from Project Runway advised, be fierce.
Congratulations, please share a few photos of the completed unit. And, if you feel like it, any sonic changes you noticed before vs. after Tuba.
I flipped the diode today, and I was glad I managed it. Replacements wont be here until Tuesday.
Re-installing now. Next up is debugging one output board.
This is the only PS board I have. I have a franken-VFET v1 amp. Special chassis (boy is that a challenge working inside that) OS2 kit from store, and Version 1 boards from NP, with only the diodes installed.
I figured that if I had to order boards from gerbers, and source the parts, I would start with the Tuba board.
Re-installing now. Next up is debugging one output board.
This is the only PS board I have. I have a franken-VFET v1 amp. Special chassis (boy is that a challenge working inside that) OS2 kit from store, and Version 1 boards from NP, with only the diodes installed.
I figured that if I had to order boards from gerbers, and source the parts, I would start with the Tuba board.
This is my only filter for the Vfet. I have not hooked it up as yet since I am having some trouble getting it adjusted. CH1 only goes down to 2.53VDC (between TP1 and TP2) and give an output of 35VDC. CH2 starts at 3.1VDC (between TP1 and TP3) and drops to 2.3VDC when the relay operates. I can adjust CH2 to 2VDC. CH2 gives an output of 34.4VDC at 2.3VDC between TP1 and TP3.
Connect three 1K resistors in series (giving a 3K resistor with 3 times greater power handling) and connect the two ends of the 3K between CH1_V+ and CH1_GND. Adjust the trimmer and attempt to get 2.0V from regulator input to regulator output. Repeat for CH2.
Math: power dissipation = V*V/R = 36*36/3000 = 0.43 watts total; each 1K resistor dissipates a third of that, namely 0.14 watts. Warm but not hot.
If you don't have three 1K resistors, post a table of the resistors you do have (Rvalue, quantity you've got) and maybe an alternative arrangement might work.
Math: power dissipation = V*V/R = 36*36/3000 = 0.43 watts total; each 1K resistor dissipates a third of that, namely 0.14 watts. Warm but not hot.
If you don't have three 1K resistors, post a table of the resistors you do have (Rvalue, quantity you've got) and maybe an alternative arrangement might work.
Hi Mark thanks, I am away all this week so I will have to work on this on Saturday. I should have a number of 1K resistors.
I just finished building and testing my second Tuba. This one works just fine, I am able to adjust both CH1 and CH2 to 2V between the test points with the 3K load.
I will try to work on the other Tuba over the weekend.
