No, I hadn't try the AD/TI search functions. There might be LT models to simulate too.
Yes, there are negative regulators to use with the LT3042 @ 15v.
There are also options to be used with higher voltages, although for up to 80v input only with 60v max output. Not the 68v I'd be interested in.
It's unlikely I will find eBay reg pcbs using any of these chips, but I will look into that. There's always the evaluation kits, but they will certainly be rather expensive.
Yes, there are negative regulators to use with the LT3042 @ 15v.
There are also options to be used with higher voltages, although for up to 80v input only with 60v max output. Not the 68v I'd be interested in.
It's unlikely I will find eBay reg pcbs using any of these chips, but I will look into that. There's always the evaluation kits, but they will certainly be rather expensive.
No, I hadn't tried the AD/TI search functions. There might be LT models to simulate too.
Yes, there are negative regulators to use with the LT3042 @ 15v.
There are also options to be used with higher voltages, although for up to 80v input only with 60v max output. Not the 68v I'd be interested in.
It's unlikely I will find eBay reg pcbs using any of these chips, but I will look into that. There's always the evaluation kits, but they will certainly be rather expensive.
Yes, there are negative regulators to use with the LT3042 @ 15v.
There are also options to be used with higher voltages, although for up to 80v input only with 60v max output. Not the 68v I'd be interested in.
It's unlikely I will find eBay reg pcbs using any of these chips, but I will look into that. There's always the evaluation kits, but they will certainly be rather expensive.
I am currently contemplating to design a PCB using LT3081/LT3091 in TO-220 package. I hope to make it all with through hole components. When I start with it I'll open a dedicated thread.
Now THIS looks very interesting!
LT3045 LT3094 positive and negative regulated linear power supply +-5/9/12/15V | eBay
Or this:
LT3045 LT3094 Positive and Negative Low Noise Regulated Linear Power Supply for | eBay
The one with the heatsink below seems to allow using an external input, where we can implement a CRC input filter, that seemed to influence PSRR quite a bit on my simulations.
LT3045 LT3094 positive and negative regulated linear power supply +-5/9/12/15V | eBay
Or this:
LT3045 LT3094 Positive and Negative Low Noise Regulated Linear Power Supply for | eBay
The one with the heatsink below seems to allow using an external input, where we can implement a CRC input filter, that seemed to influence PSRR quite a bit on my simulations.
The layouts are really spacious around the regs. The distance between the decoupling caps and the regs is larger than I would like but if it works why not.
It means that inputs can withstand negative up to 22V voltage (it won't burn, and won't work, of cause).
LT3081 would need help to improve its PSRR. Input CR(L)C filter comes to mind. Ideally I would think of using a DC-DC converter in front of it which allows for much lower CR(L)C components values to achieve >100dB extra PSRR at the switching frequency. Doing it for 50 or 60 Hz mains frequency requires large capacitance and either relatively big value resistor which increases the voltage drop and lowers efficiency or large size choke.
Considering the actual parts size, the caps, particularly the more critical output ones, seem to be around 10mm off, which I'm not sure it's not within specs.
Only getting one and checking that with a ruler would answer that.
I'm much concerned about the actual schematic they used, and, as you also raise, how they could get that price to be that low.
Either fakes or a large batch they could get from someone else that sold them for a lower price.
To check the first option only actual measurements can answer that.
In any case, the bet is low to try it to power an actual circuit. Which in my case would be a RIAA preamp.
Yes, that's what I seemed to notice in my LT3081 simulations, which I thought were wrong because they were worst than the ones I had achieved even with a discrete regulator, which I can show you for you to see.
So I thought my implementation is wrong, and why I asked for a working schematic.
Probably you didn't see them, but there are a few threads dealing with remarkable regulators, some even as good or better than the superregulators.
I've seen all these threads dealing with all kinds of regulators but I prefer relative simplicity of the IC based LDO regs.
Except for the discrete regulator I will use on the power amplifier, some of the others I plan to build and listen to on the RIAA preamps I will be building.
That is a very sensitive circuit, and it's quite likely there are audible differences between the different regulators.
That is a very sensitive circuit, and it's quite likely there are audible differences between the different regulators.
Be aware that some of the LT3045 on eBay have been fakes. Do a quick google search for fake LT3045 and you probably find an article on how to spot some of them.
I googled and didn't find that article on fake 3045.
What do you think about those 3042 eBay boards that I showed? Are they fake too?
For some reason I can't find it either.. Some of the cheapest boards were fakes with wrong package markings regarding package type or wrong number of legs. So check the Ti's datasheet regarding numbering and count the legs on the chip to improve the likelihood of getting a real one. Perhaps someone on this forum have measured their cheap LT3042?
I think if you buy something low-noise, like LT3042/3045 you have to have microvoltmeter (to have posibility to measure noise), because otherwise why you need such a low-noise parts?
OK, folks. Coming back just to update.
The regulators I need are to be used on a phono preamp, so you will need a very low noise supply.
I could simulate plenty of them, some of the best were measured by John Walton on Linear Audio.
https://linearaudio.nl/sites/linearaudio.net/files/v4 jdw.pdf
I am working on opening another thread with the simulations I did, compared to the actual Walton results.
Now you can find the LT3045 in a small version that you can use to replace a fixed voltage 3-pin regulator. Price is reasonable.
https://pt.aliexpress.com/item/1005...c16709322398561672e52ba!12000025008751691!rec
These folks, who probably also designed this 3-pin adapter, sell a V+/V- power supply, at a very reasonable price.
The LT chips excel at noise and PSRR, but they are not as good as others on impedance.
I can upload the asc files from the simulations I did, if anyone is interested.
There's a new family of regulators that use 3X7 regulators existing supplies, and you add a small pcb called "denoisator" and it improves all measured figures by a large margin.
But the most reliable high end power supply still continues to be the Jung/Didden design called Super regulator. Now you can buy the two pcbs for V+/V- regulators, buy all the listed parts, easily available in Mouser, and have a state of the art PS.
The regulators I need are to be used on a phono preamp, so you will need a very low noise supply.
I could simulate plenty of them, some of the best were measured by John Walton on Linear Audio.
https://linearaudio.nl/sites/linearaudio.net/files/v4 jdw.pdf
I am working on opening another thread with the simulations I did, compared to the actual Walton results.
Now you can find the LT3045 in a small version that you can use to replace a fixed voltage 3-pin regulator. Price is reasonable.
https://pt.aliexpress.com/item/1005...c16709322398561672e52ba!12000025008751691!rec
These folks, who probably also designed this 3-pin adapter, sell a V+/V- power supply, at a very reasonable price.
The LT chips excel at noise and PSRR, but they are not as good as others on impedance.
I can upload the asc files from the simulations I did, if anyone is interested.
There's a new family of regulators that use 3X7 regulators existing supplies, and you add a small pcb called "denoisator" and it improves all measured figures by a large margin.
But the most reliable high end power supply still continues to be the Jung/Didden design called Super regulator. Now you can buy the two pcbs for V+/V- regulators, buy all the listed parts, easily available in Mouser, and have a state of the art PS.