What's the power supply voltage to Kubelik? The TP7 and TP10 voltages are strange, I haven't been able yet to figure out how they've been arrived at.
l use the LM 317 board from you. From memory , it is very close to 20V. I will measure again when reach home this evening.
The other functioning channel 's measurement for TP6 ,9 are about 10.5v
The other functioning channel 's measurement for TP6 ,9 are about 10.5v
Running through this morning's list of TPs, the issue between TP4 and TP6 has now gone away. So either there was an error in the first list with TP4 and TP6 voltages or the fault is intermittent.
Would you be able to measure the voltages on U8 pins 1,2 and 3? The left side of the opamp might be faulty.
U8 voltage measurement without i2s input.
I did notice an intermittent short at C9 capacitor. Taken out to check and resolder back this morning
I did notice an intermittent short at C9 capacitor. Taken out to check and resolder back this morning
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Ah from that it looks like the opamp may still be working fine. Perhaps the problem is in the transistors making up U8's output stage. What are the voltages on either side of R34 and the Q10 side of R32?
On both sides of R32, it measures 0v.
R34-side nearer to Q10 measures 0.639v and the other side 16.46v
R34-side nearer to Q10 measures 0.639v and the other side 16.46v
I'm fairly sure there's at least one spare PNP transistor (BC856B) in the kit yes.
If you can't find a spare transistor you can get it working by putting a 0R for R34.
If you can't find a spare transistor you can get it working by putting a 0R for R34.
Replace Q9. I have 2 BC856 left over.
New measurements on both ends of R34 are 9.86v and 10.46v
On both sides of R32, l have 9.36v now
New measurements on both ends of R34 are 9.86v and 10.46v
On both sides of R32, l have 9.36v now
Thanks to Richard for the excellent support. Kubelik is singing beautifully now.
I wish l have the skill of Richard to troubleshoot!!
BTW, the new version is a even better singer?
I wish l have the skill of Richard to troubleshoot!!
BTW, the new version is a even better singer?
A new version of Kubelik? Do you mean Toscanini? I haven't compared them but should be a bit lower noise as its overclocking the DAC chips by 50%.
Unfortunately, after playing for few minutes, notice this noise that sounds like static coming from same channel. Will try to upload audio recording later