can you put an signal generwtor audio signal into the grid and measure the output? That willtell you if there’s a problem with the tube etc.
Just wondering if there have been any more deliveries of RTZ PCBs?
https://docs.google.com/spreadsheets/d/1uKnO0GdXeRVG1_gdMzKvs1F0184cyWlzM4Ul6nbt7Io/edit#gid=0
https://docs.google.com/spreadsheets/d/1uKnO0GdXeRVG1_gdMzKvs1F0184cyWlzM4Ul6nbt7Io/edit#gid=0
My boards have arrived, many thanks @nautibuoy
Looking forward to assembling and testing as soon as parts arrive.
Looking forward to assembling and testing as soon as parts arrive.
Hi Ray,
Can I ask a few questions regarding your soldering techniques of the boards please? You can tell me to get lost and learn for myself but hopefully you can assist?
1. What temp and airflow do you tend to use for the resistors and caps?
2. What nozzle size? I have 3 with my kit, I have only tried the medium one so far (about 8mm dia, the smaller one is around 5mm)
3. How on earth do you manage to get the correct amount of solder paste on the pads!???! My stuff is yucky, very thick and not easy to place.
4. What is your technique with regard to the order of placing components? Do you go smallest to largest? Specific sections of pcb in batches? ICs/transistors after res/caps?
5. In what circumstances would you chose iron over air for the SMD components? Tacking down ICs prior to air?
I have some practice pcbs and I've been trying both iron and air station for a variety of package types and I have to say my results are not yet up to a standard that I feel I want to adopt for the DAC pcbs. Having watched numerous videos I'm not really much the wiser. lol.
Practice, practice I guess, I just thought I'd ask the expert and try to shortcut some failings.
Cheers,
Tony
Can I ask a few questions regarding your soldering techniques of the boards please? You can tell me to get lost and learn for myself but hopefully you can assist?
1. What temp and airflow do you tend to use for the resistors and caps?
2. What nozzle size? I have 3 with my kit, I have only tried the medium one so far (about 8mm dia, the smaller one is around 5mm)
3. How on earth do you manage to get the correct amount of solder paste on the pads!???! My stuff is yucky, very thick and not easy to place.
4. What is your technique with regard to the order of placing components? Do you go smallest to largest? Specific sections of pcb in batches? ICs/transistors after res/caps?
5. In what circumstances would you chose iron over air for the SMD components? Tacking down ICs prior to air?
I have some practice pcbs and I've been trying both iron and air station for a variety of package types and I have to say my results are not yet up to a standard that I feel I want to adopt for the DAC pcbs. Having watched numerous videos I'm not really much the wiser. lol.
Practice, practice I guess, I just thought I'd ask the expert and try to shortcut some failings.
Cheers,
Tony
Hi Tony. Just to dispel absolutely that I am by no means an expert but my smd soldering skills are slowly improving and I'm getting more confident but still have issues that need rework. My hands are pretty steady but my eyesight is past its best so I work with a USB microscope (about £30 on Amazon) - it takes a little getting used to the hand/eye coordination but is worth the effort.
I'm left-handed so to minimise the chance of disturbing anything I generally work from right to left across a board. I paste a section of the board then place the components, then repeat across the board. With squeezing a syringe of paste it is hard work so progressing in sections helps to rest my hand too - I'm going to get one of those paste application tools for next time. If it's cold the paste is more viscous and I sometimes keep it close to a radiator when I'm working.
I have found that the right paste makes so much of a difference and I use the ChipQuik one I linked to a few posts back - it also has a very long shelf-life and stores well without any special arrangements. Using a minimal amount of paste is critical and I apply with the amber/orange needle - there are finer needles but without a tool to drive the syringe this is the best I can use without getting blisters on my palm. I've learned that more paste is not good as you get too many bridges - you just need a tiny amount. For the sort of ICs on the RTZ board I don't use an iron to tack them down but just position them onto the pasted pads - it's sufficient to hold them in place unless you're careless. For round-bodied parts, like the diodes on my RTZ board, I do use a little extra paste to stop them rolling of the pads when you use the hot-air.
For a board I try to only use an iron for rework, generally with soe solder wick to address solder bridges. I'll use an iron though if I just need to solder a few parts, especially on an already populated board. The technique that works for me is to apply paste to the pads, place the part and hold it in place with something like a kitchen match while I touch one pad with a fine iron bit, then repeat for the other pad(s).
My hot-air station doesn't have variable flow - it isn't blasting air, seems a relatively gentle rate. I set the temperature to around 340°C. My nozzle is around 8mm square. I work one area and once the solder starts flowing I systematically move across the board in lawn mowing fashion.
I haven't tried doing parts on both sides of a PCB yet! I may resort to using an iron to solder the underside of the RTZ board?
As a last resort, for stuff that I think is just too difficult, I call on my mate and his reflow oven.
I'm sure there will be people that say I do it wrong but my success rate is improving so that'll do for me.
I'm left-handed so to minimise the chance of disturbing anything I generally work from right to left across a board. I paste a section of the board then place the components, then repeat across the board. With squeezing a syringe of paste it is hard work so progressing in sections helps to rest my hand too - I'm going to get one of those paste application tools for next time. If it's cold the paste is more viscous and I sometimes keep it close to a radiator when I'm working.
I have found that the right paste makes so much of a difference and I use the ChipQuik one I linked to a few posts back - it also has a very long shelf-life and stores well without any special arrangements. Using a minimal amount of paste is critical and I apply with the amber/orange needle - there are finer needles but without a tool to drive the syringe this is the best I can use without getting blisters on my palm. I've learned that more paste is not good as you get too many bridges - you just need a tiny amount. For the sort of ICs on the RTZ board I don't use an iron to tack them down but just position them onto the pasted pads - it's sufficient to hold them in place unless you're careless. For round-bodied parts, like the diodes on my RTZ board, I do use a little extra paste to stop them rolling of the pads when you use the hot-air.
For a board I try to only use an iron for rework, generally with soe solder wick to address solder bridges. I'll use an iron though if I just need to solder a few parts, especially on an already populated board. The technique that works for me is to apply paste to the pads, place the part and hold it in place with something like a kitchen match while I touch one pad with a fine iron bit, then repeat for the other pad(s).
My hot-air station doesn't have variable flow - it isn't blasting air, seems a relatively gentle rate. I set the temperature to around 340°C. My nozzle is around 8mm square. I work one area and once the solder starts flowing I systematically move across the board in lawn mowing fashion.
I haven't tried doing parts on both sides of a PCB yet! I may resort to using an iron to solder the underside of the RTZ board?
As a last resort, for stuff that I think is just too difficult, I call on my mate and his reflow oven.
I'm sure there will be people that say I do it wrong but my success rate is improving so that'll do for me.
Hi Ray,
Many thanks for your detailed reply - loads to think about and try out.
😎
I have made a start on the DAC board. I have started with the iron initially although I have some of the paste you recommended arriving tomorrow.
I find the resistors work well with the iron but these pesky little dual-transistor packs are tedious with the iron. I may try those using air for the rest. My eyesight (with magnifying headband) isn't too bad but this will strain it to the max!
It's going to take me weeks at this rate but it's the journey that counts!
I don't think there is right or wrong, just what works for you best. After watching loads of videos you come to realize that everyone has their own preferred techniques.
Cheers,
Tony
Many thanks for your detailed reply - loads to think about and try out.
😎
I have made a start on the DAC board. I have started with the iron initially although I have some of the paste you recommended arriving tomorrow.
I find the resistors work well with the iron but these pesky little dual-transistor packs are tedious with the iron. I may try those using air for the rest. My eyesight (with magnifying headband) isn't too bad but this will strain it to the max!
It's going to take me weeks at this rate but it's the journey that counts!
I don't think there is right or wrong, just what works for you best. After watching loads of videos you come to realize that everyone has their own preferred techniques.
Cheers,
Tony
No problem Tony, happy to try and help. I suggest you try using less solder - maybe the ChipQuik stuff will help - I'll be interested to see how you find it.
It took me all day, with some breaks, to do the top-side of one RTZ DAC board!
It took me all day, with some breaks, to do the top-side of one RTZ DAC board!
That is super-accurate! 
Mine looks a right dog's breakfast in comparison. I will try with the new paste and see how I get on.
Mine looks a right dog's breakfast in comparison. I will try with the new paste and see how I get on.How is everyone getting on with their builds?
I have about 85% of the SMD parts fitted to the DAC board but will not be able to complete it until I get the OPA2210 op-amps in late Feb. I did get some from AliExpress but I don't really trust them to not be fake so for only a wait until Feb for the Mouser ones it's not worth it since switching them out once the Rifa caps are fitted around them would be less than fun.
I'm getting my hand in now with the hot air method, I am slowly being converted to it. It is quite therapeutic in a way, placing all the tiny parts and lining them up! The only ones that really annoy me are the diodes though! Little b****s keep on rolling away!
I have about 85% of the SMD parts fitted to the DAC board but will not be able to complete it until I get the OPA2210 op-amps in late Feb. I did get some from AliExpress but I don't really trust them to not be fake so for only a wait until Feb for the Mouser ones it's not worth it since switching them out once the Rifa caps are fitted around them would be less than fun.
I'm getting my hand in now with the hot air method, I am slowly being converted to it. It is quite therapeutic in a way, placing all the tiny parts and lining them up! The only ones that really annoy me are the diodes though! Little b****s keep on rolling away!
I’ve yet to order the BOM (i have a second project I am designing in parallel). I’m almost ready with the order (the BOM for this is in a project so i can just add it).
The second project is a ADC for testing - so I hope this will connect nicely to give some numbers 🙂
I’ve always soldered at any angle however watching YT vid on SMT soldering - stay comfy, tack and solder then rotate the board (not done that for years with THT!) and finish the other side.
The second project is a ADC for testing - so I hope this will connect nicely to give some numbers 🙂
I’ve always soldered at any angle however watching YT vid on SMT soldering - stay comfy, tack and solder then rotate the board (not done that for years with THT!) and finish the other side.
@MarcelvdG - what’s the maximum current draw on the power rails?
I’m busy designing/plundering low noise regulator designs for my ADC clock and the ADC also needs a +/-15V & +5V supply so it makes sense be me to perhaps make some low noise shunt regulators at the same time for this project.
I’m busy designing/plundering low noise regulator designs for my ADC clock and the ADC also needs a +/-15V & +5V supply so it makes sense be me to perhaps make some low noise shunt regulators at the same time for this project.
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Ray you may have a solder bridge on U7 on the left side part way up.I had planned to progress my SLOB speaker project today but with the inclement weather that wasn't really on so I spend a few hours putting my first RTZ DAC board together - soldering was with my hot air workstation so most of the time was spent applying solder paste (oh for a solder stencil!) and placing the components. I've inspected the board under my USB microscope and I'm pleased with the results, I only had to deal with a couple of solder bridges - time will tell if everything survived the soldering 😟
Still some parts to do when I get them and there's the bottom of the board to do too.
Thanks Nick but I saw that previously when i did a close inspection - it was just bit of debris.
See post #88 for currents measured on my prototype, https://www.diyaudio.com/community/threads/return-to-zero-shift-register-firdac.379406/post-6999623 , and add 50 % or so to have margin for exemplaric spread.