Much better for EMI/RFI. Such things can radiate and couple to cables and tube elements no matter if you electrically filter them through the power feed. Select 20MHZ bandwidth limit too on the scope's channel when measuring any PSU. Also keep in mind not to near the probe or its cable to the scope's screen because some emit enough digital noise that it can pick up.
Hi Sir
What is the combination of c101 and 103 or that gives a more tuby character. Can I use a paper in oil for 103?
I had burnt the mosfet and now using 2x irf 9540. The result is not very good. The sound shrunk and the vp to p increased to 20mv from 2 to 3mv. Waiting for the fairchild from ebay. I cannot imagine.. Such a vast effect
Lastly is it OK to use twisted solid core for v and current sense jumper to the pcb. Since it's about 30cm away from the heater. What method is the best? I do not have enough position to place it close.
What is the combination of c101 and 103 or that gives a more tuby character. Can I use a paper in oil for 103?
I had burnt the mosfet and now using 2x irf 9540. The result is not very good. The sound shrunk and the vp to p increased to 20mv from 2 to 3mv. Waiting for the fairchild from ebay. I cannot imagine.. Such a vast effect
Lastly is it OK to use twisted solid core for v and current sense jumper to the pcb. Since it's about 30cm away from the heater. What method is the best? I do not have enough position to place it close.
C103 is for electrolytic and R107 jumper scenario, for C104 and R107 Zobel scenario you can also use PIO.
The 9540 has much input capacitance so its normal for the open loop response to close in. Parts from ebay... Good luck. Are you located in Europe? If those parts will prove suspicious see in Element14 (Farnell UK).
You can use solid core. For 30cm which is not close at all, also try two wire classic mode with 12 AWG cable to compare. See post one here, there is a link explaining how to convert the mode. Its very easy.
The 9540 has much input capacitance so its normal for the open loop response to close in. Parts from ebay... Good luck. Are you located in Europe? If those parts will prove suspicious see in Element14 (Farnell UK).
You can use solid core. For 30cm which is not close at all, also try two wire classic mode with 12 AWG cable to compare. See post one here, there is a link explaining how to convert the mode. Its very easy.
Finally got it stable
I'll take that result considering long cable run
I added a capacitor 220uf and up at the receiving end near the heater and that took care of the final ripple 2hifh is around 200mv. Below that value start to oscillate like mad 600 mv VP. Yikes. Finally settle on 1000uf. Cheapo cap. Like the sound best.
Up the reservoir cap to 10000 uf that further reduced some ripple. Just a standard smh. Since I'm going for 900 ma.
4 wire run around 30cm is better for my case. 2 wire I got those huge sine wave curve in the oscilloscope.
Didn't use pio. Too much ripple for long cable run since wire is longer . But instead use 220uf silmic in the middle and kept the rest , helps to roll off and thickened the sound some to get it more tubey sound.
Using 2x 9530 again. Waiting for fairchild. 2x 9540 did not work, unstable wave and ripple . Sound awful as well. Hope 9530 holds well and dont overheat again before the fairchild FQP3P20 arrives.
Very very huge different when the ripple is tamed. Flat sounding became huge, rounded, bodied. Bass became bottomless without being out of control. back in black when properly implemented will not sound sterile, yet musical. It could sound sterile detailed and compressed when it's not done right.
Since I see nobody tried Bib on tube filament thought I share some of what I tried.
Thanks for help and suggestion Nick.
I'll take that result considering long cable run
I added a capacitor 220uf and up at the receiving end near the heater and that took care of the final ripple 2hifh is around 200mv. Below that value start to oscillate like mad 600 mv VP. Yikes. Finally settle on 1000uf. Cheapo cap. Like the sound best.
Up the reservoir cap to 10000 uf that further reduced some ripple. Just a standard smh. Since I'm going for 900 ma.
4 wire run around 30cm is better for my case. 2 wire I got those huge sine wave curve in the oscilloscope.
Didn't use pio. Too much ripple for long cable run since wire is longer . But instead use 220uf silmic in the middle and kept the rest , helps to roll off and thickened the sound some to get it more tubey sound.
Using 2x 9530 again. Waiting for fairchild. 2x 9540 did not work, unstable wave and ripple . Sound awful as well. Hope 9530 holds well and dont overheat again before the fairchild FQP3P20 arrives.
Very very huge different when the ripple is tamed. Flat sounding became huge, rounded, bodied. Bass became bottomless without being out of control. back in black when properly implemented will not sound sterile, yet musical. It could sound sterile detailed and compressed when it's not done right.
Since I see nobody tried Bib on tube filament thought I share some of what I tried.
Thanks for help and suggestion Nick.
Attachments
See to have better air circulation around the sink and/or better thermal pass from Mosfets to the sink. Low insulation and contact heat resistance in other words. 0.9A is not much for those Mosfets you use. Try not to have excess input voltage vs output voltage and/or too not too much CCS spare current vs what the heater draws so to avoid excess heat.
After diode is 15.75v to 12.6 v
R301 is 1 ohm to get 1A. According to calculator. Using 1.7 v diodes led x6
Heat sink is pretty beefy. Weight 300g schedule to chassis as well and and extra 50 g heat sink glued to it
Most of time is slightly warm. But out of sudden it could get hot. Asia room temperature I guess
The tube is 0.45 a X2
Should I try 1.5ohm?
R301 is 1 ohm to get 1A. According to calculator. Using 1.7 v diodes led x6
Heat sink is pretty beefy. Weight 300g schedule to chassis as well and and extra 50 g heat sink glued to it
Most of time is slightly warm. But out of sudden it could get hot. Asia room temperature I guess
The tube is 0.45 a X2
Should I try 1.5ohm?
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Good outcome. You can measure the voltage drop directly across the current setting resistor (or a combination's) no need to measure its input and output pin vs GND and then subtract numbers.
You should also remember to check the voltage drop across the current setting resistor with each Mosfet sample replaced and even more importantly when you make a CCS Mosfet model type change. Because they differ in VGS. So to know if the current limit remains enough for the load, and if it is, the spare portion also remains logical for heat. Else readjust as you did.
You should also remember to check the voltage drop across the current setting resistor with each Mosfet sample replaced and even more importantly when you make a CCS Mosfet model type change. Because they differ in VGS. So to know if the current limit remains enough for the load, and if it is, the spare portion also remains logical for heat. Else readjust as you did.