I saw that too
Although I need to desolder the 5532s I've previously fitted I still need the BOM to finish, but at the same time I'm public-holiday DIYing the garden (laying concrete with sandstone on top, replacing arris rail fences etc).. so I'm too exhausted to figure out the final BOM lol.
I'm currently listening to the first RTZ Filter board that I've completed, using my Noir headphone amp again. The filter board is plugged into my own RTZ DAC board mentioned in the posts above.
This one is a build I'm doing for a friend and uses NE5532 opamps. Output caps are Mundorf ZNs - they're too big for the PCB so I've had to install them on the underside of the PCB and had to make the leads thinner to fit through the PCB pad holes - they're secured with adhesive foam pads to offer some strain relief and I also have a cable tie temporarily supporting the caps.
Anyway, it worked straight off the workbench and is sounding very good right from the start.
Later I'll finish assembling the RTZ DAC board that will go with this filter board and it shouldn't be too long before I build my own filter board with the OPA opamps.
This one is a build I'm doing for a friend and uses NE5532 opamps. Output caps are Mundorf ZNs - they're too big for the PCB so I've had to install them on the underside of the PCB and had to make the leads thinner to fit through the PCB pad holes - they're secured with adhesive foam pads to offer some strain relief and I also have a cable tie temporarily supporting the caps.
Anyway, it worked straight off the workbench and is sounding very good right from the start.
Later I'll finish assembling the RTZ DAC board that will go with this filter board and it shouldn't be too long before I build my own filter board with the OPA opamps.
No Mark, apart from using a Noble volume pot my Noir is built with the parts listed in the BOM on the DIY Audio store. The Mundorf ZNs used in the RTZ project were chosen and supplied by the friend I'm building it for, though I have used Mundorf ZNs in some tube amp projects - I've not been disappointed with them but to be honest I haven't spent time doing capacitor comparisons.
Marcel, I could use some of your wisdom please. I finished assembling the second RTZ board but I have a problem. The right channel sounds fine but I have no left channel at all. As the right channel is working and I'm assuming it is unlikely that I have faults in both sections of the DAC core for the left channel I'm assuming the trouble-shooting starting point is the left channel reference (U2A/Q30) and/or the left channel clock section. I don't believe there is an issue with the reference section as DACrefL_F and DACrefR_F measure the same (4.993VDC referenced to ground).
I've checked and reflowed the pins of U20 and U23 but that's not fixed the issue. Can you make any suggestions to help isolate the problem?
I've tried both your prototype filter board and the new one I completed this morning to make sure I hadn't revealed a fault with the new one when assembling/disassembling.
I've checked and reflowed the pins of U20 and U23 but that's not fixed the issue. Can you make any suggestions to help isolate the problem?
I've tried both your prototype filter board and the new one I completed this morning to make sure I hadn't revealed a fault with the new one when assembling/disassembling.
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Is the mute relay operating? (Forget that, it's the filter you've already tested)
What about the clock to the shift registers? That is also common to both. I found the measurement of the DAC core outputs with no filter connected to be the true health check. Even when I thought it was all working fine, in fact both channels had faults in solder connections and were down on level. Reflowing the shift registers cleared all the faults. Those SSOP20's are a bit picky. lol
What about the clock to the shift registers? That is also common to both. I found the measurement of the DAC core outputs with no filter connected to be the true health check. Even when I thought it was all working fine, in fact both channels had faults in solder connections and were down on level. Reflowing the shift registers cleared all the faults. Those SSOP20's are a bit picky. lol
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I have to say, I am still so pleased to have this DAC, it is without a doubt the best DAC I've so far had in my system. I've had a few, including some pretty special TDA1541A based ones. I thought non-oversampling ladder was the most realistic after going through loads of chip based delta sigma DACs over the years. However, this DAC, together with the "simple PCM2DSD" modulator has opened my ears to what is possible from 16 bit 44.1. I'm listening to old rips of CDs with a depth and realism I've never heard before. The 1541 gets close but still sounds a bit rough and wooley compared to analogue whereas this DAC does everything so well. Well done Marcel!
I've started to do some measurements.
U7, U9, U14 and U16 are all seeing 4.99VDC on pin20 and 1.19VDC on pin 11 (referenced to ground) so, as the right channel works, I'm surmising that the DAC reference/clock supply section is working correctly and the issue is in the left channel clocking section.
U7, U9, U14 and U16 are all seeing 4.99VDC on pin20 and 1.19VDC on pin 11 (referenced to ground) so, as the right channel works, I'm surmising that the DAC reference/clock supply section is working correctly and the issue is in the left channel clocking section.
Problem solved! It was a short under the left channel input UFL connector.
As the DAC will be used with input via the P1 header I've removed the UFL connectors - it was a devil to remove them because of the ground plane soaking up the heat and I managed to remove some pads but ultimately no harm done.
Now listening in stereo and everything is good.
As the DAC will be used with input via the P1 header I've removed the UFL connectors - it was a devil to remove them because of the ground plane soaking up the heat and I managed to remove some pads but ultimately no harm done.
Now listening in stereo and everything is good.
I'm feeling quite pleased with myself - I've now assembled three RTZ PCBs, two RTZ DAC and one RTZ output filter, and the only problem has been the UFL short so I'm pleased that the soldering of all those small ICs and transistors has been 100% successful first time (so far - I've probably just given the kiss of death to the next one).
I finished assembling one of ppy's DSD'it boards this morning and after initially testing it with a 'No-DAC' RC filter I've now installed it onto the RTZ DAC.
DSD'it is a hardware based solution (a Beaglebone cape) to deriving DSD256 from PCM data, using two coupled ASRC chips, (SRC4192 and AK4137). I've setup ppy's Beaglebone firmware (based on Botic) to run Roon RAAT and streaming PCM using the Roon interface. I'm not really doing critical listening but first impressions are extremely positive and I think very close to the HQPlayer/JLSounds input I have been using with the RTZ DAC builds.
https://www.diyaudio.com/community/threads/simple-dsd-src-for-beaglebone.358147/
The only config change I had to make was to set the Botic mute flag to be high for mute, to match the JLSounds arrangement.
I think I'll order an AntMiner (Beaglebone derivative) from AliExpress as ppy has said his firmware is compatible and they cost less than a Beaglebone.
https://www.aliexpress.com/item/1005003832749081.html?spm=a2g0o.cart.0.0.10a238dael9PgY&mp=1
DSD'it is a hardware based solution (a Beaglebone cape) to deriving DSD256 from PCM data, using two coupled ASRC chips, (SRC4192 and AK4137). I've setup ppy's Beaglebone firmware (based on Botic) to run Roon RAAT and streaming PCM using the Roon interface. I'm not really doing critical listening but first impressions are extremely positive and I think very close to the HQPlayer/JLSounds input I have been using with the RTZ DAC builds.
https://www.diyaudio.com/community/threads/simple-dsd-src-for-beaglebone.358147/
The only config change I had to make was to set the Botic mute flag to be high for mute, to match the JLSounds arrangement.
I think I'll order an AntMiner (Beaglebone derivative) from AliExpress as ppy has said his firmware is compatible and they cost less than a Beaglebone.
https://www.aliexpress.com/item/1005003832749081.html?spm=a2g0o.cart.0.0.10a238dael9PgY&mp=1
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Over the weekend I dropped off the RTZ DAC I built for my friend and last evening he hooked it up for a listen - this is the assessment;
"...the thing sounds amazing. Really brilliant. |'m sure it's theoretically possible that something else might sound better, but this is by far the best digital sound I've heard. I love it."
For context, he's a keen vinyl advocate with a really top-notch analogue system.
"...the thing sounds amazing. Really brilliant. |'m sure it's theoretically possible that something else might sound better, but this is by far the best digital sound I've heard. I love it."
For context, he's a keen vinyl advocate with a really top-notch analogue system.
I have one last set of PCBs (DAC and filter) for the RTZ DAC if anyone is interested?
If you are, but are daunted by the smd soldering it might be possible to bribe me to spend the time populating the boards - not something I want to make a habit off as it is pretty tedious but content as a one-off to give Marcel's wonderful DAC a bit more exposure - happy to discuss further.
I thought I would mention it here first but I'll advertise the PCBs on Swap Meet at the weekend if there's no interest. I will also be listing a spare Valve DAC PCB, populated with all the smd parts.
If you are, but are daunted by the smd soldering it might be possible to bribe me to spend the time populating the boards - not something I want to make a habit off as it is pretty tedious but content as a one-off to give Marcel's wonderful DAC a bit more exposure - happy to discuss further.
I thought I would mention it here first but I'll advertise the PCBs on Swap Meet at the weekend if there's no interest. I will also be listing a spare Valve DAC PCB, populated with all the smd parts.