So going to finally put my dac together, looking at the regs.
Based on the datasheet, the lt3042 has a ground pad under the chip.
Ian's board has little holes and a pad to match.
Were you guys able to solder the chip pad to the board pad?
I don't have a hot air gun at home, so wondering if anyone was able to do it with an iron?
Any hints here would be appreciated.
Randy
Based on the datasheet, the lt3042 has a ground pad under the chip.
Ian's board has little holes and a pad to match.
Were you guys able to solder the chip pad to the board pad?
I don't have a hot air gun at home, so wondering if anyone was able to do it with an iron?
Any hints here would be appreciated.
Randy
Hi Randytsuch
I did a couple of them. I could not imagine doing it with an iron.
The LT3042 was my incentive to finally buy a hot air station. Picked one at Amazon. About $60 CAD. Best buy investment in DIY hobby. They work really well.
Second best investment was magnifying thingy with a light you wear on your head. I use this for everything now.
The LT3042 went on with no issue but use very little solder paste.
I did a couple of them. I could not imagine doing it with an iron.
The LT3042 was my incentive to finally buy a hot air station. Picked one at Amazon. About $60 CAD. Best buy investment in DIY hobby. They work really well.
Second best investment was magnifying thingy with a light you wear on your head. I use this for everything now.
The LT3042 went on with no issue but use very little solder paste.
Thanks, that's what I suspected.
I've used a head band type magnifier for years now, I can't work without it.
Randy
@bigpandahk,
I'm not sure what 12nF caps you mean. I see the optional 3.8n caps to ground before the summing stages, but I don't see the 12nF caps. What am I missing?
In any case I am using the IVStd balanced output into a balanced amplifier, so I am not even installing an opamp into the U3 position.
Sorry!
Greg in Mississippi
P.S. I think @Markw4 tried caps in that position and they may have been 12nF. BUT he had oscillation there. I don't know if that wouldn't have happened if he used the specified value (I know he didn't use that, but don't remember for sure what he used... sorry, no time to search tonight). BUT as I say above, I don't even use that stage in my current implementation.
I'm not sure what 12nF caps you mean. I see the optional 3.8n caps to ground before the summing stages, but I don't see the 12nF caps. What am I missing?
In any case I am using the IVStd balanced output into a balanced amplifier, so I am not even installing an opamp into the U3 position.
Sorry!
Greg in Mississippi
P.S. I think @Markw4 tried caps in that position and they may have been 12nF. BUT he had oscillation there. I don't know if that wouldn't have happened if he used the specified value (I know he didn't use that, but don't remember for sure what he used... sorry, no time to search tonight). BUT as I say above, I don't even use that stage in my current implementation.
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@bigpandah,
Thanks. I had forgotten that Ian had posted the IVStd schematic with the Rasmussen Filtering changes.
I'm attaching the schematic Joe Rasmussen had originally posted as the 3rd picture in the first post of this thread:
Practical Implementations of Alternative Post-DAC Filtering
Joe's comment about the 12nF caps:
"The 2 x 12nF caps can be finely tweaked to restore response to 'flatness' "
BTW, note the added .33F/5V supercaps, a technique adopted by Allo. Kewl that Ian provided positions for our DIY experiments along those lines!
Actually I have only used the pre-IV R-C filtering and not the 'equalization' caps. So no, I did not. At the tender young age of 63, I know I do not hear a db or so frequency droop at 20k.
Greg in Mississippi
P.S. IF one wants to argue the merits for or against the Joe Rasmussen pre-IV filtering regime, please refrain from posting here and feel free to start a new thread so it can devolve into name-calling and get closed as all of the other ones did. I WILL NOT ENGAGE in such discussion here. What I have said, that I'm really enjoying my Ian GB setup with a lower IVStd IV stage filter cutoff, using the Rasmussen pre-IV filtering, sporting NDK SDA clocks, and powered by Ian's LiFePO4 supply, is as far as I'll go.
Thanks. I had forgotten that Ian had posted the IVStd schematic with the Rasmussen Filtering changes.
I'm attaching the schematic Joe Rasmussen had originally posted as the 3rd picture in the first post of this thread:
Practical Implementations of Alternative Post-DAC Filtering
Joe's comment about the 12nF caps:
"The 2 x 12nF caps can be finely tweaked to restore response to 'flatness' "
BTW, note the added .33F/5V supercaps, a technique adopted by Allo. Kewl that Ian provided positions for our DIY experiments along those lines!
Actually I have only used the pre-IV R-C filtering and not the 'equalization' caps. So no, I did not. At the tender young age of 63, I know I do not hear a db or so frequency droop at 20k.
Greg in Mississippi
P.S. IF one wants to argue the merits for or against the Joe Rasmussen pre-IV filtering regime, please refrain from posting here and feel free to start a new thread so it can devolve into name-calling and get closed as all of the other ones did. I WILL NOT ENGAGE in such discussion here. What I have said, that I'm really enjoying my Ian GB setup with a lower IVStd IV stage filter cutoff, using the Rasmussen pre-IV filtering, sporting NDK SDA clocks, and powered by Ian's LiFePO4 supply, is as far as I'll go.
Attachments
There is something I don’t understand.
Why would supercapacitors be better than a good quality capacitor like the Silmic, black gate or Oscon (my favourite for digital).
I have been trying Maxwell supercapacitors 1,5f/5v on the rpi input and fifopi (on input and on the designated positions on the board) I did not find them to be better than a standard cap value.
The big capacitance has some disadvantages, it takes a while to charge (with high current), big capacitors have higher esr by design.
The supercapacitor will never be completely discharged while in operation. When using it on the input of the fifipi it takes like half a minute or longer to discharge after power down. So the most part of the capacitance will never be used.
The better choise will be to use a good quality cap with a standard value.
Why would supercapacitors be better than a good quality capacitor like the Silmic, black gate or Oscon (my favourite for digital).
I have been trying Maxwell supercapacitors 1,5f/5v on the rpi input and fifopi (on input and on the designated positions on the board) I did not find them to be better than a standard cap value.
The big capacitance has some disadvantages, it takes a while to charge (with high current), big capacitors have higher esr by design.
The supercapacitor will never be completely discharged while in operation. When using it on the input of the fifipi it takes like half a minute or longer to discharge after power down. So the most part of the capacitance will never be used.
The better choise will be to use a good quality cap with a standard value.
Depends what someone would consider an upgrade. OPA1612 will produce the least distortion. Bursons will add a little perhaps euphonic distortion that some people like. Such distortion can be used to mask other distortion in the dac system that has not be otherwise corrected. On the other hand, if the dac has been cleaned up well by doing things such as adding Ian's shield board, and maybe the output stage filter mod, then maybe less remaining distortion to mask.
D
Deleted member 537459
Ultra capacitor has the best low noise performance. As well, it also has super low internal resistance. So that it can deliver huge demand current in a very sort time to get best dynamic performance than any other power supplies. However the smaller ones have much higher ESR, so the performance will be very limited. Your feel is correct. (But still can provide some kind of compensations)
To make use of the advantages of the high current power ultra capacitor, it needs a special designed power supply. The scheme could be very complicated. I'm working on it but have no update so far.
Or, you can try LifePO4, it's not as difficult as ultra capacitor.
Regards,
Ian
Couple more questions.
Anybody try an Allo Sparky SBC for this?
Wondering if it would be better for audio than a Pi. Seems closer to a pi2, no wifi.
Its just too bad shipping to US is so much, list price for card is low enough.
Anybody try the Allo Dietpi Web gui image?
DietPi - Allo.com Web GUI Image - DietPi / Fuzon
I need to setup my pi and found this today.
Anybody try an Allo Sparky SBC for this?
Wondering if it would be better for audio than a Pi. Seems closer to a pi2, no wifi.
Its just too bad shipping to US is so much, list price for card is low enough.
Anybody try the Allo Dietpi Web gui image?
DietPi - Allo.com Web GUI Image - DietPi / Fuzon
I need to setup my pi and found this today.
Thanks! Board design was heavily inspired by your boards
I/V transformers are custom made by my technical partner here in Germany. I will send you the board for evaluation once we finished the initial testing and are confident with the design.
Greetings,
Denis
This thread is mostly by users of his new ESS dual mono 9038 dac, but should have been clear.
Most use his fifo pi too.
The allo software only supports allo products, which makes sense.
I found a used sparky, so going to try it.
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Let us know about your finding/tests as second-hand Sparky-ies may pop up more frequently due to the advent of RPi 4 and Allo's RPi CM-based DAC platform...