anyway, to cut short this epopeia ............ if you ever try*** KB1 with different PSU, and have same problems - without seeing proper pics, can say just one way to fix it - replace Korg tube
if different PSU is enough to cure problems you have, then even better
***connect and listen/hear .............. you can't measure that hiss/whizz problem, with DMM
if different PSU is enough to cure problems you have, then even better
***connect and listen/hear .............. you can't measure that hiss/whizz problem, with DMM
https://www.digikey.no/no/products/detail/triad-magnetics/WSU240-0500/3094985
Maybe that first and then the tube. It is the most expensive and most hassle to replace. ZM will have the best advice.
agree, the build is tidy. Money is on the PSU and the tube.
Maybe that first and then the tube. It is the most expensive and most hassle to replace. ZM will have the best advice.
agree, the build is tidy. Money is on the PSU and the tube.
The B1 Korg's input impedance is roughly equal to its 50K volume pot. 50K Ohm is much, much higher than the typical TDA1541A I/V resistor value, so the value of the I/V resistor is not materially affected by the input impedance of the B1 Korg.
For instance, if your I/V resistor is 50 Ohm, the paralleled resistance with 50K is 49.95 Ohm.
By the way, I have a TDA1541A dac too and I also only have an I/V resistor at its output, and then it is connected to my preamp for voltage gain.
For instance, if your I/V resistor is 50 Ohm, the paralleled resistance with 50K is 49.95 Ohm.
By the way, I have a TDA1541A dac too and I also only have an I/V resistor at its output, and then it is connected to my preamp for voltage gain.
hello Ben Mah,
i am thinking of removing the input side of korg nutube preamp like volume pot, capacitor and resistor,
and directly feed them to the dac with iv resistors.
is that possible??🤔
Here it is a very interesting, thank you ZM,
KB1 for DAC, I think this can also be implemented for other current output dac's?
well, DACs are hardly subject of this thread 
yes, wherever you need gain stage like this one you can use it , I/V conversion appropriate for DAC in case
yes, wherever you need gain stage like this one you can use it , I/V conversion appropriate for DAC in case
I'm having a discrepancy between test points 7 and 8 on a just completed build. The voltage looks to be within a good range on TP7, but TP8 is about 18 V and the trim pot varies it only a volt or two. However the plate on the right does change in brightness. When researching the kit I thought I saw a video or post by someone with this problem, and of course now I can't find it. I double checked all component placement. The other test voltages seem fine. Any ideas?
Please measure the DC voltage across the 332K and R1 resistors for both channels.
Can you adjust the right channel pot so that the voltage across the right channel 332K resistor is the same as the voltage across the left channel resistor?
What is the value of R1? Was this a diyAudio kit of parts?
Can you adjust the right channel pot so that the voltage across the right channel 332K resistor is the same as the voltage across the left channel resistor?
What is the value of R1? Was this a diyAudio kit of parts?
