Excellent, ZM. Dug up 4k7s on hand replaced R1. Dialed back P1. Reset to 640mV, 32v rail at 64.1
Connected full range open baffle Betsy. Playing mono copy of Rolling Stones Now.
Time to start the power supply on mono block #2.
I applaud your circuit design skills 🫡
Connected full range open baffle Betsy. Playing mono copy of Rolling Stones Now.
Time to start the power supply on mono block #2.
I applaud your circuit design skills 🫡
Blame Pa, I'm just conduit
Strong and Omni one, but still just conduit
And, I don't know how to repair Porsche
Ha! A high throughput conduit. Don't know boxer motors, but can handle Fiat / Alfa. Will report on monoblock #2, it should go faster now that I have a working template.
Powered up monoblock #2. Rail is 63V loaded, good.
640mV across R4
Issue: C+ to grounds read .30V
Any thoughts on what to check?
It does make heat on both sinks.
640mV across R4
Issue: C+ to grounds read .30V
Any thoughts on what to check?
It does make heat on both sinks.
SIT PCB :
voltage across ZD4
voltage at JFet gate ref. to GND
voltage at SIT gate ref. to GND
voltage across R8
voltage across ZD4
voltage at JFet gate ref. to GND
voltage at SIT gate ref. to GND
voltage across R8
Across ZD4 = 2.6V
SIT Gate at PCB to GND = .63mV
Across R8 = 606mV
Where do I measure Jfet gate?
SIT Gate at PCB to GND = .63mV
Across R8 = 606mV
Where do I measure Jfet gate?
JFet gate voltage, ref. to GND - any side of R6
confirm that you have proper connection "thin wire to -60Vdc from lower pcb", meaning that you have -60V at -U pad
voltage at R7, other side (one is connected to U-), ref to GND
confirm that you have proper connection "thin wire to -60Vdc from lower pcb", meaning that you have -60V at -U pad
voltage at R7, other side (one is connected to U-), ref to GND
R6 - GND = 83.8mV
-U pad 89.9 mV to ground
89.6mV one side of R7 to GND, 96.7 mV the other side of R7 to GND
-U pad 89.9 mV to ground
89.6mV one side of R7 to GND, 96.7 mV the other side of R7 to GND
you don't have connection from -60V at lower (Mu) pcb through thin wire, soldered to -U pad on SIT pcb
practically - thin wire connecting "-U" pads, one on upper and second on lower pcb
edit: rule is - always take care of measuring and mentally differentiating and - if needed - writing exact polarity of voltages
in many cases/occasions that's irrelevant, but sometimes not doing it right can cost you ( or anyone) dearly
practically - thin wire connecting "-U" pads, one on upper and second on lower pcb
edit: rule is - always take care of measuring and mentally differentiating and - if needed - writing exact polarity of voltages
in many cases/occasions that's irrelevant, but sometimes not doing it right can cost you ( or anyone) dearly
sage advice in your edit.
I had neglected a jumper on the right side of the PS PCB, connecting the upper and lower sections to the negative rail. That's now installed.
Cooking now, seeing 63.6V PS loaded, 31.9V C* to GND (interestingly, unlike monoblock #1, I don't see that from C* to chassis - wonder if that's a problem)
629mV across R4 Mu PCB
edit: and measuring U- to chassis, 1.4V, U- to GND shows 63.4V
well, only in case you got two different gen of pcbs, but that's ZM - even with care and all mental concentration, ookoop is my middle name
care to post pics, so I can see where I did wrong?
as afar as I remember - differences between various gens of pcbs are mainly gilding the lily, no any substantial change
have you NTC from audio GND to chassis, or direct connection between those?
as you have monoblocks, feel free to make direct connection
NTCs are proper when building stereo amp with common PSU or dual mono (two monos in one case)
Thanks ZM! For ease an earlier pic of the four boards side by side so you can verify gens. (1st photo below)
I don't have audio ground from NTC to chassis. (2nd photo)
Also I neglected to run a wire from the 'chassis' via next to the NTC on the PS PCB. Shall I add those in both monoblocks?
I don't have audio ground from NTC to chassis. (2nd photo)
Also I neglected to run a wire from the 'chassis' via next to the NTC on the PS PCB. Shall I add those in both monoblocks?