The LM317 is a series type chip reg. If you ask it no work, it does not create any. If you ask it less than those mA current, its internal voltage reference will not function.
The Ultrabib is a constant current source biased parallel regulator. Big part of load current in this shunt reg is the high bias current burned in its output Mosfet already.
In other words it works like loaded even when its client load is in standby mode i.e. works on itself. That is why its sinks are always warm or even hot.
The Ultrabib is a constant current source biased parallel regulator. Big part of load current in this shunt reg is the high bias current burned in its output Mosfet already.
In other words it works like loaded even when its client load is in standby mode i.e. works on itself. That is why its sinks are always warm or even hot.
What values should i use for Cx, Cs, Rs for UB1.3? I could not find the values in the build guide.
Thanks.
Thanks.
Those are experimental values based on specific model transformer and diode bridge type resonance. They counteract that resonance. A "Quasimodo" tuning device and an oscilloscope is used to arrive at Cx Cs Rs proper values for each occasion. It triggers the ringing hence named after the famous Hunchback of Notre Dame story's church bell ringer. You can search about it in DIY Audio. Else skip those parts.
I see the BC560 and PF5102 can be had on reverb from teabag but not the FQP3P20. It is obsolete. Can anyone recommend suitable replacements? I have found these but not sure
FQPF7P20
IRF9610PBF
And FQP3N30 is also obsolete. Would these work in place?
FQP4N20L
IRF610PBF
FQPF7P20
IRF9610PBF
And FQP3N30 is also obsolete. Would these work in place?
FQP4N20L
IRF610PBF
IRF9620 IRF620 should work.
IRF9610 IRF610 not as strong as the originals but as fast. Should work reliably for up to 750mA CCS setting.
IRF9610 IRF610 not as strong as the originals but as fast. Should work reliably for up to 750mA CCS setting.
Hi Salas,
I've acquired three excellent sets of +/- 1.3 UBib w/ mini kits from Tea. Use case is Miro AD1862 DAC with Pass D1 I/V.
First question please: for R1 for the 5V digital side, I think 3.9 ohm on the + R1? In reading this thread I saw for the Soekris a smaller value for the neg side. Does that hold true for Miro's also? What value for neg R1? Here's Miro's post for reference:
I did read your build guide and followed your recommendations for transformers, respectively 9V for the 5V supply, 15V for the 12V supply, and 32V for the 30V (D1) supply.
Many thanks in advance for all you do,
Jim
I've acquired three excellent sets of +/- 1.3 UBib w/ mini kits from Tea. Use case is Miro AD1862 DAC with Pass D1 I/V.
First question please: for R1 for the 5V digital side, I think 3.9 ohm on the + R1? In reading this thread I saw for the Soekris a smaller value for the neg side. Does that hold true for Miro's also? What value for neg R1? Here's Miro's post for reference:
Expect this as "safe minimum" with LM6171 in the I/V:
+-40mA for digital (+-5V)
+-60mA for analog (+-12V)
The real consumption will be less (perhaps half of that).
Schematic examples in datasheet are for both "high performance" and "high resolution" on +-5V digital supply. I would say, the larger the voltage difference between analog and digital (analog > digital), the less the possibility of digital interference - but that's a humble theory unless we see the internal diagram of the AD1862
+-40mA for digital (+-5V)
+-60mA for analog (+-12V)
The real consumption will be less (perhaps half of that).
Schematic examples in datasheet are for both "high performance" and "high resolution" on +-5V digital supply. I would say, the larger the voltage difference between analog and digital (analog > digital), the less the possibility of digital interference - but that's a humble theory unless we see the internal diagram of the AD1862
I did read your build guide and followed your recommendations for transformers, respectively 9V for the 5V supply, 15V for the 12V supply, and 32V for the 30V (D1) supply.
Many thanks in advance for all you do,
Jim
Just received ultrabib v1.3 circuit boards from teabag. Does anyone know which PCB house manufactures these boards and the other boards on the diyaudio store. They are all such high quality like from oshpark but they aren't purple.
Well, I'm back. Sorry, I've been having some health issues, which is why I'm only posting now.
So, like Salas showed me, I made this little bridge rectifier board. So far, so good.
On the other hand when I carried out the wiring of the ultrabib to this rectifier bridge I made (again) a wiring error which burned R1 but not only that, because the negative side of the card no longer works.
What I noticed is that the LEDs no longer light up even after changing R1.
When I try to measure M1 the LEDs light up a little.
I would actually like some guidance on how to troubleshoot my card, what should I check first and how to do it.
Hi, no worries, we do worse all the time. Good health to you.
First check with the DMM in diode mode that every bridge diode is still healthy. Then off course replace R1, next check and replace M1 if needed. Also check Q2.
First check with the DMM in diode mode that every bridge diode is still healthy. Then off course replace R1, next check and replace M1 if needed. Also check Q2.
Best is to pull from PCB and put them on a component tester. Simpler is to check VGS voltage for MOSFET or Vbe voltage for transistor while working. Few volts for VGS or less than 1V for Vbe. For transistor when not working it is also easy to check diode voltage between base and the other two legs. DMM diode mode, red probe for P type on base pin or black probe for N type on base pin.
Asking for a friend, 🙄
He and I are using your wonderful UltraBiB regulator to power our ECDesings 5V DAC. Sounds great.
We can't leave well enough alone, though! He has suggested adding a pair of 100F 2.7V ultra caps, in series, to the output to lower ESR. (Similarly to what Ian Canada does for the Raspberry Pi: PurePi II.)
Is this safe to do or should there be a soft start prior to the UntraBib? Or is there another way?
Thank you for your help as usual,
Rush
He and I are using your wonderful UltraBiB regulator to power our ECDesings 5V DAC. Sounds great.
We can't leave well enough alone, though! He has suggested adding a pair of 100F 2.7V ultra caps, in series, to the output to lower ESR. (Similarly to what Ian Canada does for the Raspberry Pi: PurePi II.)
Is this safe to do or should there be a soft start prior to the UntraBib? Or is there another way?
Thank you for your help as usual,
Rush
Its an experiment. If you can easily restore a failure, go ahead. There's always room for failure in an experiment. The current limiter moderates the risk but it doesn't eliminate it. The ultra caps may backfire for instance.
@Salas - Currently building 3 shunts for a DAC + D1. I got the first one, 5VDC working.
Struggling with the second shunt: Positive side appears good based on first power up. Negative side, LED's not illuminated, and R1 immediately started smoking. I went through the components, they look like they are all in the right places and oriented correctly. I observed MI reads shorted so I pulled it out. Tested it, and it's fine. I do observe the vias read shorted across the M1 pads. What might this indicate I check next?
Thanks much in advance!
Jim
Struggling with the second shunt: Positive side appears good based on first power up. Negative side, LED's not illuminated, and R1 immediately started smoking. I went through the components, they look like they are all in the right places and oriented correctly. I observed MI reads shorted so I pulled it out. Tested it, and it's fine. I do observe the vias read shorted across the M1 pads. What might this indicate I check next?
Thanks much in advance!
Jim