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In Reply to: RE: P4 power supply using the BELLESON regulator and mouse problem posted by GStew on December 31, 2010 at 12:09:05
Sounds like you're providing several new wrinkles that will benefit us all.First, thanks for sharing the info on the new Belleson 2A regulators. I hadn't seen them yet. They look to be THE current contender for DIY supply regulators... I'd even look at their 2A regulator if I were doing another linear/hybrid supply for the main 12v rail. I strongly suspect they are a better choice than the AMB Sigma... and based on your comment about the high-current 5v Salas, it may not be suitable (BTW, can you point to any web references or discussions on this aspect of the Salas? I'd like to see what can be done to make the voltage level more consistent).
You know, as I ponder it more, I think I need to put an order in for a couple of 12v & a 5v 2A regulator from them.
On voltages, earlier this summer, I had been in communication with a lurking-inmate from Oz who had a fully linear supply built. He had pots to adjust the voltages and found (similar to other postings here) that a slightly lower voltage was best sonically. He didn't get around to reporting on the 3.3v rail, but found the sweet voltages for his setup were 4.6v & 11.8v for the ATX connection.
BTW, he used the John Swenson choke-filtered supply for his basic raw DC supplies and was very happy with the results. Very interested in what you're doing for the choke-filtering for your 5v raw supply if you're willing to share it.
Those are the voltages I settled on based on his suggestions.
And I'd agree that using an LT1086-3.3v is likely your best bang-for-the-bux for the 3.3v rail. Sorry, tho, I haven't taken the time to put in my LT3080-based regulator on that rail, so I don't have a definitive opinion on that.
As for heatsinks on the rectifiers for the 5v raw supply, I totally agree with that. Those devices are the hot-spots of my fully-linear supply and putting heatsinks on them was one of the first things I did when trying to resolve my early issues that I thought were related to overheating (but were not). I'd also suggest heatsinks for the other regulators too, especially if you have a fairly high input-to-output voltage differential on them. All of my regulators (all LT1083 or LT3080 based at this time) run from moderately-warm to hot, but I do have fairly high differentials on all of them.
On powering the HDD, if you have a 2.5" SATA drive, they only need the 5v rail. I believe that 3.5" drives need both the 5v & 12v, but I cannot confirm that... it may have changed with the newer 'Green' drives. But I strongly suspect that the best sound quality will be had by using an entirely separate supply (or pair of them) for the HDD instead of sharing it with the USB 5v supply.... the drive(s) seem to be electrical-noise hot-spot(s) in our cMPs.
Finally, my experience with the sonic benefits parallel yours. 'Dense' is the adjective that comes to mind... lot of details, lot of textures, all presented in an easy-to-listen-to, but musical fashion. But I bet your Belleson-based supplies with the choke-filtering on the 5v raw supply might be the best sounding implementation out there currently.
Thanks... And Happy New Year too!
Greg in Mississippi
P.S. I have a few tweak comments too... will put them into the EVS Ground Enhancer tweak sub-thread you, Theob, & Playmate discussed awhile back.
Everything matters!
Edits: 12/31/10 12/31/10Follow Ups:
Using the HAMMOND 100mH 5A (195T5)choke between two caps - nothing clever.
Then on to the DANIELs PCB. I am able to use the PCB on the heatsink I had laying around which is absurdly oversized but better safe than sorry.
I am stealing Swenson's rectifier filter and using his recommended rectifiers for the P24 supplies. For the other supplies I used FAIRCHILD "Stealth" rectifiers.
BELLESON has led me to believe that the 2A reg will be able to do the job with a large heatsink. I am using the latest recommended MB which I hope will allow me to get away with this regulator. I can always plug in the ATX for outside of cMP duty like adding music files.
I am using heatsinks for the others, just not big ones. This is what I am using: http://www.mouser.com/ProductDetail/Ohmite/RA-T2X-64E/?qs=sGAEpiMZZMttgyDkZ5WiumlCfl50RTwzl4D6wMWH1QQ%3d.
For the JULI@ and the P4 (what I have done so far) they are warm. No need for any more. To make them more efficient I am not using anything between the heatsink and the transistor. I am using that trick thermal compond the computer gamers use for their CPUs. One does need to make sure there is no way the heatsink comes in contact with anything else, though. You can touch them without getting shocked as long as you are not grounded! From what has been said about the P24 12 & 3.3V requirements I cannot imagine these not being sufficient. Nice thing about these sinks one can mount the regulator at the connector - the one for the JULI@ is on the board, for the P4 I am using about two inches of wire before the connector. The JULI@ regulator is not using the DANIELs PCB.
For P24 this will not be possible, obviously!
One can certainly make a shunt reg have a constant voltage - you have to add some kind of feedback and an error amplifier of some kind. This is what Allen Wright does and I feel certain Hynes does this also. Hynes uses lots of SMD devices so it hard to see what is actually happening. It has been awhile since I had the ones I have in front of me to look. Nonetheless, there is no other way.
For audio circuits the SALAS type reg is probably superior. There really is no need (that I can see) for voltages being absolute, though it is a nice bonus. One can worry about just what mischief an error amp and feedback loop can do - they still lag behind the actual event so you get the see-sawing. I would think a slow variation is better than the quick (but never quite quick enough) reactions of an error amplifier.
Not to say I hear anything wrong with the Hynes, and plenty of other people are keeping the man very busy, so it must not be much of a problem. (Excuse my going in circles)
My HDD is not a 2.5" so I guess I need to have both rails. I think you are right about separate supplies for USB and HDD. It is so easy with the DANIEL's PCB and fixed voltage versions of the LT1086. No need to push the limits of the regulator.
Now, if you could just tell me where I am going wrong with the "mouse" supply!
Thanks,
Rick McInnis
Thanks for the info on your choke setup. What size caps? How'd it look in the sim?
On the rectifier heatsinks, I am using very oversized rectifiers... IXYS DSEP30-06A, a 30A 600v FRED. My heatsinks on them are pretty small in size... but do make a diff. The other difference is that I've setup all my supplies as 2 diodes full-waves instead of a 4 diode full-wave bridges. I've also used the MSR860 diodes that Peter Daniel uses in his NOS DAC, but prefer the IXYS ones.
I need to try the Swenson filters. See his comments here that suggest it'll work on just about any PSU setup:
http://www.diyhifi.org/forums/viewtopic.php?f=15&t=1957&start=15
I'm running about 2.2A on the GA-G31M-S2L motherboard. I need to check with Belleson if their 2A reg will work with that much current with a substantial heatsink. My P4 is at just under .5A & I use a smaller heatsink than what you referenced. All of my supplies have about 5V-6V of input-to-output differential.
I checked the Hynes shunt I have here for a Juli@ upgrade & it does appear to have an error amp.
I'll have to build up the high-current Salas & see how tight they can be set. I was assuming the 2 LED reference would keep the output pretty stable.
Again, thanks for all.
Greg in Mississippi
Everything matters!
fluctuations in line voltage.
If yours is super stable it will not make much a difference.
I'll readily admit I did not feel like fooling around with the SALAS - as usual, I bought the parts and then thought that the BELLESON's make it easy! I will do that!!!
I might eventually use a SALAS on JULI@, I do not think super stable (divorced from the line) voltage is all that important there.
I am using the i3 board so I am hoping that it does indeed use less power.
(You need to make this upgrade, it really makes a difference) Board is on sale at NEWEGG, who I despise at the moment.
Can't remember if I said, that the reason I am using the choke with the % volts supply is that I am going to have to minimize the in/out voltage differential and figured I should give the regulator as little work as possible to do.
On the other regulators I have used more dropout voltage, I suspect similat to your choices.
I am still enjoying what the EVS version of the Purvine idea does for my speakers, I have only used them on the TAD drivers, the 4001 especially known for aggressiveness, and found they made them sound much more refined.
Theo is far more adventurous than me with his DIY efforts. I tried the battery on my woofers but did not hear much of anything but it might take time to hear the difference below 500 hz (?). I have not tried the battery in place of the EVS devices. I will.
I have not tried Mr. Maher's devices. I am intrigued. They strike me as even more mysterious than loops of wire and batteries hanging off of drivers!
If the battery works as well as Theo reports, and as you know I think Theo has very perceptive hearing, Mr. Schultz might be back to modifications soon. The battery is easy to implement. What Ric was/is doing is time-consuming. I know I would not want to make one in the same fashion as his. I was glad to send him the money. They are well made.
I have been involved in a very silly thread about the battery at AA TWEAKS - a guy who makes cables is going on and on about how the "pool of electrons" idea is preposterous and CANNOT work. A guy making cables saying this. Says: where's the proof? A guy making cables wants proof? I asked him about cables being PROVED to work. He says they have not (duh!) but that doesn't stop him. He has not tried the tweak. I think he has been on an extended NEW YEAR'S "imbibement" or maybe he is lacking some other form of diversion, who knows?
Bye,
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