I tried down to 8 boards but still had the distortion, so I gave up on the project for now and stuck with the older boards.
Do you mean the noise is only happening while you turn the volume knob? Or is it happening continuously if the volume pot is set to something less than 100% volume?
What kind of noise is it? Crackling, buzzing, scratching, hum, white/pink/red noise like?
Can you send a schematic of how things are wired up (DDDAC output state, connection to pre amp, input stage of pre amp)?
It's a "popping" like sound only when the volume knob is around 10 and two o'clock if there is a music signal or not. Playing music after the volume is set works like a dream.
The "popping" is present with or without Cinemags transformers on output. I have checked the wiring and all seems fine.
It's not a big deal for me, but maybe for some others ?
The "popping" is present with or without Cinemags transformers on output. I have checked the wiring and all seems fine.
It's not a big deal for me, but maybe for some others ?
When you were testing without the transformers, was this direct/DC coupled to the amp input or was there a blocking capacitor? A schematic showing your DDDAC output and pre-amp input stage would be useful.
Hello,
I am using the dddac and i have an LCR filtre designed for cd player output 20? 30 years ago by Jean Hiraga.
Of course digital audio at that time was rather poor.
I did ask Doede if i should remove the filter because his dddac is designed in a peculiar way. Probably he is enjoying holiday.
So anyone has an idea?
Greetings, Eduard
I am using the dddac and i have an LCR filtre designed for cd player output 20? 30 years ago by Jean Hiraga.
Of course digital audio at that time was rather poor.
I did ask Doede if i should remove the filter because his dddac is designed in a peculiar way. Probably he is enjoying holiday.
So anyone has an idea?
Greetings, Eduard
Attachments
Hi folks,
I am using a RPI+KALI combo which is fed to my i2s DAC. At present I power the Kali using the standard wall wart power supply by Allo and that indirectly powers on the RPI too.
I have just received an Isolator board by Allo and am not clear as to how to power each components now? I have also received the battery pack from Allo. Question:
RPI-->ISOLATOR-->KALI
If I power on the isolator using the lifepo 18650 batteries, will that power on the RPI too? (maybe that defeats isolation then). If the isolator doesnt power on the RPI, do I buy a separate power supply for the RPI?
Then coming to KALI, it will require a second power supply for itself?
If someone can clarify quick, I can get these going asap.
Cheers
Kartick
I am using a RPI+KALI combo which is fed to my i2s DAC. At present I power the Kali using the standard wall wart power supply by Allo and that indirectly powers on the RPI too.
I have just received an Isolator board by Allo and am not clear as to how to power each components now? I have also received the battery pack from Allo. Question:
RPI-->ISOLATOR-->KALI
If I power on the isolator using the lifepo 18650 batteries, will that power on the RPI too? (maybe that defeats isolation then). If the isolator doesnt power on the RPI, do I buy a separate power supply for the RPI?
Then coming to KALI, it will require a second power supply for itself?
If someone can clarify quick, I can get these going asap.
Cheers
Kartick
I'd guess that Allo should be the best source of information on that. You could also try the Kali thread.
Without seeing a schematic of the filter it's impossible to say. I would remove it in order to get a good fix on the stock sound of the DAC. Depending on how the filter is designed it may cause problems with the output of the dddac. Keep in mind that if you are using a dc coupled preamp you need to use coupling capacitors on the outputs of the DAC unless you have the output transformer option.
Hello,
I asked Doede himself by email and i will act according to his answer.
This filter is designed to filter the '' negative side effects " caused by the AD converter. There is a coil in series and then a small cap in series with a resistor in parallel. I did send Doede the actual values but it might be illegal to put the actual values on the internet for all to see.
I did reread the dddac info. There is no digital filtering used so probably there will be no need for this lcr unit!!
Greetings, Eduard
Eduard, Have you tried the DDDac with and without the filter? I’m still using mine without any filtering. I have never been a big believer in break in but I must admit that the DAC did seem to improve greatly after about 50 hours or so of playing time. I am using it single ended right now into an Aikido tube preamp and it sounds very good but different then it did with the balanced output going into an Aleph P. The Aleph P had some issues so I am now considering transformers to convert balanced to single ended or perhaps eventually building a balanced tube preamp.
Happy Listening, Brian
Happy Listening, Brian
Hello Brian,
I am using the Sowters Doede is using too.
Removing the filter is time consuming! If it would have been easy i could just try it. If Doede tells me my dac will sound better without filter i will remove it next time i will open my preamp.
Will have to be opened soon because i bought an AVC volume control.
greetings, Eduard
I am using the Sowters Doede is using too.
Removing the filter is time consuming! If it would have been easy i could just try it. If Doede tells me my dac will sound better without filter i will remove it next time i will open my preamp.
Will have to be opened soon because i bought an AVC volume control.
greetings, Eduard
Sounds like a straight forward LC filter with a loading resistor. Since this filter would pass dc to the preamp you would still need a series capacitor when using the filter, unless your preamp has ac coupled inputs. It is worth trying it to see if you like the sound. As long as the shunt resistor value is not too low it should not load down the outputs of the DAC.
I would be worried that the filter LC circuit might oscillate in combination with the transformer. Do you have a scope to check this?
With the transformers on the output the filter is more of an unknown. The transformer itself forms a 2nd order low pass filter that you tune using the load resistance on the transformer output. With the filter as a load who knows what the interaction will be. I would definitely try it without the filter.
I checked the Hiraga filter in combination with a 4-deck DAC and it does not look good. See Graph. I would recommend to not use filters like this. To be honest, most of the HF junk is filtered anyway by the Sowter Transformer.
Without transformers there is still the option to use the optional filter capacitors on the mainboard....
