Yes! pin 22 to +5V . not to GND, you can check PCb!
If all is ok!
you check CS 8414, it is die
If all is ok!
you check CS 8414, it is die
yes! 21 to GND:
I think Your CS8414 have problem, when you turn on, the LEd is on, that is ok.
you se circuit here:
DAC End 2 - the AD1865N-K with single ended vacuum output stage
Quanghao:
I agree that CS8414 may have problem.
I also tried a DIR9001 - CS8414 board that I had and with no signal it has LED off.
Can there be anything else?
Thank You
Bob
I agree that CS8414 may have problem.
I also tried a DIR9001 - CS8414 board that I had and with no signal it has LED off.
Can there be anything else?
Thank You
Bob
you are the second person the same way! you try to check whether the weld quality is not bad?
I'm trying to wire up the following R-core to acheive 8.15V..
R80-36 260-230-0-230-260(90mA). 2.5-0-2.5(3A).(3.15-0-3.15)X2(3A)
I read further back in the thread that I needed to use 2.5 + 2.5+ (3.15) parelled, I dont really want to guess what this means and would rather ask the best way to wire it up.. As If I were to guess I'd connect the 2.5 and 2.5 and join the 3.15 wires together, which is most likely wrong?
R80-36 260-230-0-230-260(90mA). 2.5-0-2.5(3A).(3.15-0-3.15)X2(3A)
I read further back in the thread that I needed to use 2.5 + 2.5+ (3.15) parelled, I dont really want to guess what this means and would rather ask the best way to wire it up.. As If I were to guess I'd connect the 2.5 and 2.5 and join the 3.15 wires together, which is most likely wrong?
Quanghao:
You were right. I put together another CS8414 and placed it in DAC. Now the LED is lit without anything plugged into the SPDIF. Turns off when I plug signal in.
Problem - still no music
The jumper is in place.
6.21V on filaments.
285V on tubes.
Where should I look next?
Best
Bob
Thanks for your help
Did you use inductors on the dac board, if you didn't, don't forget to bridge that gap!
Do you have access to a scope?
Do you have access to a scope?
Cool, check for a wave output across the DAC board then, eliminating that. If you still get nothing through that then follow it back, through to the other side of the inductors, past the 200r's to pics 21 and pin 4 of the ad1865.
If you get nothing there, then i have no idea, as i don't understand the digital side.
If you get nothing there, then i have no idea, as i don't understand the digital side.
Thanks
I'll get the scope on it during the next couple of days. I was optimistically 😉 hoping for something that I could just use the DVM to do.
Ok then... without scope, check voltage after plate resistors on the I/V board, check voltage onto the actual pins of the tubes.
Check for any DC and AC voltage across the DAC outputs.
You said all voltages were good onto the Ad1865?
Check for any DC and AC voltage across the DAC outputs.
You said all voltages were good onto the Ad1865?
Thanks again.
I will follow your first suggestion and follow the digital signal with a scope.
Voltages to the AD1865 are as specified.
I have 107V on anodes and 6.21 on filament.
Relay shows a short to ground when off and 9k out to ground when on.
Best
Bob
I will follow your first suggestion and follow the digital signal with a scope.
Voltages to the AD1865 are as specified.
I have 107V on anodes and 6.21 on filament.
Relay shows a short to ground when off and 9k out to ground when on.
Best
Bob
Hi
I'm no expert, but would have thought the following.
FAO apelizzo
a few pages back (post#2119740) you posted an alternative i/v stage. Any chance of a bit more info (better schematic/external links) on this for who might be interested ?
Obviously, don't want to spoil this thread too much.....
TIA
Attachments
I have a question regarding the power supply for the for the filament.
What is the purpose of C12 and C13?
Also what is the purpose of D6 and D7?
/ David
What is the purpose of C12 and C13?
Also what is the purpose of D6 and D7?
/ David
The alternative I/V stage I posted was a single ended differential circuit with cathode follower output buffer. The gain of the circuit is not enough unless you increase the value of R23-24 from 200R to a little more enough to obtain 2Vpp output. I don't think 200R value is critical here. If you want I can post more info.
LC Filter
I would like to know why the LC filter (like the AudioNote DAC) has been adopted in this project to roll off frequency before 20KHz. I know that's an option, but what is the benefit other the short to floor residual digital noise?
Did anyone tried with and without it?
I would like to know why the LC filter (like the AudioNote DAC) has been adopted in this project to roll off frequency before 20KHz. I know that's an option, but what is the benefit other the short to floor residual digital noise?
Did anyone tried with and without it?
Last edited:
SSHV upgrade
It would be good idea to upgrade the power HV supply in this project.
Quanghao is this in your to do list?
In my previous DAC I used shunt PSU instead of expensive Jensen cap. I guess it makes the difference
Heater power supply also needs to be improved. Perhaps constant current on heater with different arrangement.
It would be good idea to upgrade the power HV supply in this project.
Quanghao is this in your to do list?
In my previous DAC I used shunt PSU instead of expensive Jensen cap. I guess it makes the difference
Heater power supply also needs to be improved. Perhaps constant current on heater with different arrangement.
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