deadwood83
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- Sep 1, 2022
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I am not a fan of linear supplies. I will get that rout of the way now.
However, I find myself in need of something approaching such a supply. I have a janktastic DAC (with some promising attributes) which takes 5VDC because it has basically no power conditioning whatsoever. The whole path to AVCC is Wallwart -> Barrel Jack -> Cap -> Relay -> Cap -> Ferrite Bead -> LDO.
See below for the map I made.
I'm more used to seeing a buck/boost chip somwhere in there operating in the hundreds of kHz or even MHz, making a linear or otherwise exceptionally clean supply a moot point. In this case, no such thing exists. The wall wart goes through two caps and a ferrite bead before hitting LDOs for AVCC, VCCA, and DVCC. It also travels directly underneath the LVDS port which defeats half the point of having the freaking shield attached to the PCB.
I have seen linear CN kits on ebay, MeanWell medical rated PSUs (though not sure if that actually has any stricter standards for PSU noise), and some DIY ' Denoiser' boards which I do not fully understand because they use older parts with lower switching frequencies. I have some TI TPS7a20 LDOs on order (to swap for the step from 5V to 3.3V) for their 20+dB higher PSRR compared to ST/Richtek SOT-23-5 but that won't help my poor LVDS which I actually plan to use for stealing I2S from my AVR.
I am looking for recommendations which are not both stupidly large and stupidly expensive.
Basic DAC spec is an XU208 and LVDS de-plexer passing through some TI isolators into the ESS chips; initialized/controlled via an STM32 which, oddly, is not isolated. OPA1612's for I/V stage and parallelled Nichicon 100uF KW (SMPS) caps (with .47uF film paralleled on board bottom). Lots of inductors and caps after the Monolithic boost for the opamp rails but jack squat for the AVCC, VCCA, and DVCC. I removed the useless HP amp board and BT; which can be handled by my AVR since it pipes data through the HDMI flow so I can steal its I2S.
This will be feeding a driverack PA2 (already adjusted I/V stage gain) which will in turn feed bi-amped (one stereo amp per channel) DIYSG Fusion 10 Pure speakers. The 'Easy' answer would have been JBL 708Ps on a Topping DX7 Pro/+ but I've had these speakers for the past decade + and I like them well enough (though I need a sub after trying the JBL 308P MK2s in my home office).
Can anybody make some sub-$200 USD recommendations? Needing to build with a kit is a bonus, as I am always a fan of hot, molten metal gluing legos together. Needing to source individual components and order PCBS from a MFG.... not as much of a bonus.
This is just for my HTPC which might be a tad overkill but hey, this money was stuck with a taobao agent who always found an excuse not to refund me for.... over two years. I do have a closet Gustard X20 but it's just sooooo honking big and would eat up valuable space in my low-profile multimedia cabinet. Still not sure where to use said Gustard since it lacks the USB card but that's a different topic.
Thanks in advance!
However, I find myself in need of something approaching such a supply. I have a janktastic DAC (with some promising attributes) which takes 5VDC because it has basically no power conditioning whatsoever. The whole path to AVCC is Wallwart -> Barrel Jack -> Cap -> Relay -> Cap -> Ferrite Bead -> LDO.
See below for the map I made.
I'm more used to seeing a buck/boost chip somwhere in there operating in the hundreds of kHz or even MHz, making a linear or otherwise exceptionally clean supply a moot point. In this case, no such thing exists. The wall wart goes through two caps and a ferrite bead before hitting LDOs for AVCC, VCCA, and DVCC. It also travels directly underneath the LVDS port which defeats half the point of having the freaking shield attached to the PCB.
I have seen linear CN kits on ebay, MeanWell medical rated PSUs (though not sure if that actually has any stricter standards for PSU noise), and some DIY ' Denoiser' boards which I do not fully understand because they use older parts with lower switching frequencies. I have some TI TPS7a20 LDOs on order (to swap for the step from 5V to 3.3V) for their 20+dB higher PSRR compared to ST/Richtek SOT-23-5 but that won't help my poor LVDS which I actually plan to use for stealing I2S from my AVR.
I am looking for recommendations which are not both stupidly large and stupidly expensive.
Basic DAC spec is an XU208 and LVDS de-plexer passing through some TI isolators into the ESS chips; initialized/controlled via an STM32 which, oddly, is not isolated. OPA1612's for I/V stage and parallelled Nichicon 100uF KW (SMPS) caps (with .47uF film paralleled on board bottom). Lots of inductors and caps after the Monolithic boost for the opamp rails but jack squat for the AVCC, VCCA, and DVCC. I removed the useless HP amp board and BT; which can be handled by my AVR since it pipes data through the HDMI flow so I can steal its I2S.
This will be feeding a driverack PA2 (already adjusted I/V stage gain) which will in turn feed bi-amped (one stereo amp per channel) DIYSG Fusion 10 Pure speakers. The 'Easy' answer would have been JBL 708Ps on a Topping DX7 Pro/+ but I've had these speakers for the past decade + and I like them well enough (though I need a sub after trying the JBL 308P MK2s in my home office).
Can anybody make some sub-$200 USD recommendations? Needing to build with a kit is a bonus, as I am always a fan of hot, molten metal gluing legos together. Needing to source individual components and order PCBS from a MFG.... not as much of a bonus.
This is just for my HTPC which might be a tad overkill but hey, this money was stuck with a taobao agent who always found an excuse not to refund me for.... over two years. I do have a closet Gustard X20 but it's just sooooo honking big and would eat up valuable space in my low-profile multimedia cabinet. Still not sure where to use said Gustard since it lacks the USB card but that's a different topic.
Thanks in advance!