Thanks, found a cold solder joit in the 0.1 ohm resistor on the output side. The resistace over the resitor was over 500 ohm. Quick resolder and it seems like the problem was fixed!
Attachments
Last edited:
at last I could complete assembling my DAM 1021. I tested it with coaxial connection from CD player with an integrated amp. The output is very very low. I had to crank up the volume all the way to full to get some sound. There is no extra noise, but the sound very low. Also, the I2S output is not working, the indicator keep on blinking when source is i2s. I am using Amanero module and rpi3 B+, through a 2 to 1 i2s switch. I am controing the DAM by AZ lite kit. Volume of AZ lite is full and volume can be controlled by AZ lite. Do I need any driver to be installed to PC? Once I connect usb to PC there is a message in pc that driver is installed. I need your kind help to fix it, I have very limited knowledge on electronics. I dont have a pc with serial port. Can I use rs232 to USB converter to connect DAM with pc? Looking forward to getting support. Regards
While waiting for replies, be sure to thoroughly search the thread. For thorough results using keywords with three characters or less I use this format in google: 'site:diyaudio.com "reference dac module" [search term]'
Yes you can use rs232/usb. Like this one.
Thank for the suggestion, I have tried my best to get a solution through this forum, and google, but ciuld not find. May be I am missing something. One more thing to say, I have made the vref mod with 1500 uf capacitor and my board is v4. Please help.
Try to get your board back to original. Your issue might be a power supply issue so roll back your mod(s). If you’re able to you should measure with a multi meter
My 2c
Thanks agsin, I have started disassembling vref. I am using a 10 volt .7 Amp power supply. If I use 12 volt then should I use any heat sink anywhere ( I saw some suggestion in this thread about ovet heat problem with12 volt). Can you please suggest what sould be the supply voltage and amperage. Regards
I’m using 9V +/- so 10V should be ok. I’m running the dam for around 1,5 years in this config so should be ok.
The current needed is in the spec sheet of the dam and is uneven for + and -
I use a 1amp psu
Spec from sheet: 7-8V AC or +-7-15V DC max 5W
P=U*I
5=10*0.5
I=0.5Ampere
That’s should be ok
So, my PSU is ok, I'll check disassembling vref. Is there any oither thing I need to check. I'll also check it with 12 volt 1 amp PSU, if if works. Regards
I think you should measure some voltage reference points. They’re mentioned in the dam1021 user manual. I think you can find it on Soekris website. Unfortunately I’m not at home so don’t have that info available.
But disassemble that vref first and try if it’s working then. Also you should try to figure out when was the last time that it did work and what did you change after that.
I have got the reference, I'll check the voltage as described. Thank you for your kind response. I was really worried as I was going through the trouble shooting.
I have got the reference, I'll check the voltage as described. Thank you for your kind response. I was really worried as I was going through the trouble shooting.
You’re very welcome. I don’t know so much but it’s an awesome DAC so it would be a pity when you cannot use. Good luck
Disassembled all vref cap. Measured the voltage at reference point - J2 and J3, all looks good. I am now using 11 volt 1 amp PSU. I connected RPI using I2S connection. Volume level is ok but it is creating some distortion. I used normal jumper cable for testing only, may be that is the reason of distortion . I need to reduce the cable length. Do I have to use shielded cable for i2s connections? Sound from the Coaxial connection source is still weak, I think there must be some kind of mistake that I have made . I am using DA101C pulse transformer. is there any orientation of this transformer? The dot mark is connected with the RCA + side. Need your kind suggestions please.
Can you show some pics of the wiring? Where is the + attached on the other side of the transformer?
This is how I connected
Attachments
It is ok now, everything working perfectly. I disassembled everything, including vref cap. Reconnected again without vref mod. Made the i2s cable as short as possible and shielded.