With 12V AC you can calculate the average and max/min ripple voltage after your rectifier.
Then you know the voltage input on your regulator and you already know the current draw and voltage out and power is easily determined. Spending a few minutes scratching on a piece of paper or in a spreadsheet to work these things out is very much worthwhile. You really should do this anyway so that you know your ripple voltage won't drop below the regulator's output voltage. This will allow you to select the correct transformer. You may then find that you would be better with a 5, 7 or 9V AC secondary. You also might want to calculate full load and no load voltage on your transformer, considering your actual loads not just the max/min voltage that is based on the transformer rating.
If you have that many transformers to include in one case then I'd really start thinking about getting a custom toroid made. I have one that has 6 secondaries. qusp's have how many secondaries? More than that again though. They don't come cheap but save you on enclosure space...
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way too high, thats an LDO, it can probably survive on 100mV drop at these currents (look it up) it will die instantly being asked to supply 100mA and swallow what 7V? with NO heatsink?
hey we all rush ahead sometimes with new toys, but you need to make sure the system is locked down before you add something new, its much easier to predict and notice problems if you know what to expect under normal operation.
the NTD1 is going to be a test, not a complicated build really, but if malfunctioning....
hey we all rush ahead sometimes with new toys, but you need to make sure the system is locked down before you add something new, its much easier to predict and notice problems if you know what to expect under normal operation.
the NTD1 is going to be a test, not a complicated build really, but if malfunctioning....
10 secondaries, I have 2 hehe. each secondary current is different, designed to feed a specific pre-regulator for a specific regulator for a specific dac pin.... $140 ea for high quality potted custom toroids, saving this much space and taking the place of 4-5 transformers it works out not too bad
All wise advices. I think with these digital circuits, power supply is the biggest task one has in construction. Separating power lines for analog, digital and clock, for DAC, than add FIFO, than add separate lines for source, in my case USB to I2S with separate, again, clock 7.5 V and 5V supply, than Arduino supply, and again in my case separate supply for VCF display...
If I was starting now, it would be much easier and I would definitely go for custom Tr. since I could forsee all of the elements. Problem is when things evolve during construction, and plans change.
As for the LDO regulators, I like Linear Systems LT3080. If space allows, sometimes having pre regulation and than another regulator is a good way of solving higher step down voltage. By all means, it is better to have the right transformer, but if you are stuck for some reason, having two regulators is not bad ether. And that is before it hits boards, that in almost all cases have their own on board regulators. That is definitely better than burning one reg with too high voltage dropout.
One reason why this TI TPS7A4700 is so attractive is because selecting voltage is so easy. I could see a nice project - board with several of these regs where user could select voltages with terminator blocks. One bigger board, but still smaller than if all is done separately. And by following very important advice from Hochopeper, heat calculation before hand will save a lots of agony.
If I was starting now, it would be much easier and I would definitely go for custom Tr. since I could forsee all of the elements. Problem is when things evolve during construction, and plans change.
As for the LDO regulators, I like Linear Systems LT3080. If space allows, sometimes having pre regulation and than another regulator is a good way of solving higher step down voltage. By all means, it is better to have the right transformer, but if you are stuck for some reason, having two regulators is not bad ether. And that is before it hits boards, that in almost all cases have their own on board regulators. That is definitely better than burning one reg with too high voltage dropout.
One reason why this TI TPS7A4700 is so attractive is because selecting voltage is so easy. I could see a nice project - board with several of these regs where user could select voltages with terminator blocks. One bigger board, but still smaller than if all is done separately. And by following very important advice from Hochopeper, heat calculation before hand will save a lots of agony.
sure quality SMPS are very good these days, but can you point to one with 10 outputs? SMPS are IMO starting to become a good option for high current circuits because you can have regulated output for a poweramp, which would be very impractical and inefficient for a poweramp normally.
here we are talking about fairly efficient linear low dropout regulators, I really dont see the value in it and I doubt it would even be cheaper. only top quality switchmode supplies are worth a look IMO, I would think twice about using one for a low level low noise circuit.
here we are talking about fairly efficient linear low dropout regulators, I really dont see the value in it and I doubt it would even be cheaper. only top quality switchmode supplies are worth a look IMO, I would think twice about using one for a low level low noise circuit.
I think DQ828 was suggesting, as a starting point, for prototyping only, not necessarily for the final implementation. He's got a point powering each new part of the circuit from a lab supply or a smps and measuring its real current requirements before designing each reg and specifying a transformer, would be quite a neat approach.
Though this method may leave you taking a lot longer to complete each stage it would give you a bit extra protection ...
Though this method may leave you taking a lot longer to complete each stage it would give you a bit extra protection ...
sure, but thats just part of the design decision, they can be designed for very low noise output and emissions, see the tests of opc's 'the wire' with the DPS600 PSUs hochopeper, me and a number of others are using, far lower noise than your dac noise floor and very high current regulated output.
you also need to consider what they can spill back onto the mains for other components, but these are all covered in a good design. its about time people got over that, the cliches nolonger hold true, but for here I just dont see the benefit.
its funny how long it takes audiophiles to leave some 'truths' behind sometimes, like how some still believe SMD parts are going to render all their music lifeless somehow, finding all sorts of justifications for it...
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ive heard its more a flat sound, the soundstage loses all depth and microdetail/dimensionality (haha you like that?) is..erm..squashed?
btw BPHK, not taking the **** out of you mate in case you personalize it, not in the slightest
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Maybe the SMPS could cover what you see as the non critical items like the Arduino, mine runs fine from a SMPS, you can alway add some regulation & filtering after it if need be.
The Linkwitz ASP runs from a SMPS but has filtering circuits after the SMPS & before the crossover section, the much acclaimed Hypex amps run from SMPS & people rave about them.
Why do you need 10 outputs!
Do you have a drawing of the Amanero board, all I can find is the overall dimension, I want to draw it to put in my Sketchup model & knowing the exact sizes can be important.
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10? lol if only.. have you seen a modern ESS dac with all the bells and whistles these days? well multiply that by 2 and you have my 4 channel dac
I mean for the transformer
SecondariesDont worry about the Amanero measurements Hifiduino had a great photo that solved that problem.
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