It's true that this threat in not for sales, but this is the right place to trade UBibs.
So please allow me to do make a proposition :
A negative UBib, new, never used, assembled with a 4700μf/40V, new from Philips.
I wish I could tweak it to make a positive shunt. Does anyone need one?
Looking to trade for a positive one, assembled or not.
I can install the trimmer and the R1 for the needs of the new owner...
and even the heat sink, beautifully sanded, shining.
Of course, USA and China are to far for this. I am in France.
Please PM me.
So please allow me to do make a proposition :
A negative UBib, new, never used, assembled with a 4700μf/40V, new from Philips.
I wish I could tweak it to make a positive shunt. Does anyone need one?
Looking to trade for a positive one, assembled or not.
I can install the trimmer and the R1 for the needs of the new owner...
and even the heat sink, beautifully sanded, shining.
Of course, USA and China are to far for this. I am in France.
Please PM me.
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A quick question, i built the 1.3 version for setting a +/-18vdc to power my Wayne's line stage boards. The transformer rated is 0-18v @1A and 0-18v @1A with the values used on the bib boards as per the kit with a 10K trimmer and 75k resistor for Vrr on both the positive and negative boards. Also used 10R 5W resistor on both the boards for R1. Now when I power it up the positive board shows up fine with output DC of 18v but the negative is stuck at max of 8.6v and the trimmer is out of turns. I need the same set of CCS usage on both the positive and negative as per the Wayne's line stage hence using 12R 5W is fine? As i had this Dale's wire wound resistor used the same. Do I need to change the Vrr to get the right voltage?
Thanks
Thanks
The R1 values you used are for very little CC current. 0.6V/10R=60mA only. It sounds like the negative rail current limits already and its output voltage naturally falls. Calculate R1s for max load's consumption in each rail plus 100mA spare. By using that formula. Those values will surely come out smaller than what you use now.
Thanks Salas, got to know that it could be a max of 50mA per channel on the Wayne's preamp boards. So 2 channels comes to 100mA and as per your suggestion of having a buffer of 100mA makes it to 200mA. I have some 3.3R 5W resistors spare got for my Soekris DAC build with the same Ultra boards. Will use them and see otherwise I need to order new ones.
Hi! I have a bunch od NF034 diodes. Can anyone tell me if I can use it in the UBib boards? I guees I can, but I am not sure... and don't find any datasheet in the internet. Thank you!
Another question. I am feeding the Soekris with one +/-5V and one +5V, using two Elpro (flat) transformers. I wonder if I have better sound with a Talema or Toroidy.
The Soekris board has the same ground circuit for both channels AND both dig and analogue circuits. I think that it would be better to use just one transformer with 3x9V, for both dig and analogue. Why to ad two different earth "lines" to the circuit if in the soekris there is only one? Two lines may add noise... the dac circuit will not like to "cope" with two lines...Any comments?
Thank you!
Another question. I am feeding the Soekris with one +/-5V and one +5V, using two Elpro (flat) transformers. I wonder if I have better sound with a Talema or Toroidy.
The Soekris board has the same ground circuit for both channels AND both dig and analogue circuits. I think that it would be better to use just one transformer with 3x9V, for both dig and analogue. Why to ad two different earth "lines" to the circuit if in the soekris there is only one? Two lines may add noise... the dac circuit will not like to "cope" with two lines...Any comments?
Thank you!
I replaced the R1 from 12R 5W to 3.3R 3W resistor on the negative board but still the output DC is stuck at max of -7.6v. I also tried with a spare 2.2R 3W resistor in the R1 position. Then I removed the Vrr 75K resistor and still the same issue unable to dial in more than 7.6v.
Then I rechecked all the transistors and they are exactly as per the schematic without any orientation problem and no shorting. Rechecked the M1 and M2 for any shorting and they are fine with the insulation pads on the bottom plate mounting. So all the parts seems to be fine with my trimmer being Bourns W103 which is 10K 0.5W. Any pointers where to look for the issue now.
Thanks
Maybe someone has an opinion to offer but those things are down to trial for personal observation usually. There are dual bridges so no mid point transformer return lines anyway.
Hmm ok let me try and do that verification. By the way I see that the LEDs when powered on glow bright and immediately reduce the intensity, so looks like something is draining the voltage and the current down. Let me do the debugging.
Thanks
I replaced the Vrr with 47K instead of 75K and did the below test.
I just did the test with power on and M1 & M2 give between 3-6v vgs (pins 1 & 3). So the mosfets are fine.
Checked all the BC (Q1,2,3,4 series) transistors and all seems to give voltage of around 0.56-0.58v except Q4 which is around 0.35v.
Thanks
I just did the test with power on and M1 & M2 give between 3-6v vgs (pins 1 & 3). So the mosfets are fine.
Checked all the BC (Q1,2,3,4 series) transistors and all seems to give voltage of around 0.56-0.58v except Q4 which is around 0.35v.
Thanks
You mean remove this one and use another BC337-40 transistor?
Also I replaced R7 with 470R resistor instead of the 270R and having R1 as 3.3R 3w for the above test.
Unfortunately I do not have any spare BC337 transistor, so need to order and wait for some days. I hope any genuine BC337 should be fine or should I look for specific vgs or hfe values?
Will replace R7 back to 270R when I replace Q4.
Thanks