I am interested in most of those USB miners. Let me chat with Novak a bit and see what we want to do, but I'm definitely interested.

Updated the list of whatall we have. I should organize it one of these days and put up some pictures.

Still looking for odds and ends. 30GH BFL units, USB miners, Technobit boards, whatever. If it's taking up space in your closet there's a chance I'll pay you for it.

Ah, unregulated. That makes sense for an AB stereo, pretty common. You had me scared for a second there though.

So anyways uh... how 'bout them 12V supplies what for the miners and stuff?

I sell 750W server PSUs with the adapter board and all cabling for $50 plus shipping. They're good for two S3 each without any trouble. I've also got 2KW setups but it requires external fans. GigaMPZ (forum user pmorici) sells adapters and cabling for 800/1000W and 1200W server PSUs, not sure on current pricing.

Server PSUs with adapters are handy because the PSU is built to sustain 100% loads indefinitely and can usually run 120% rated output (though not at peak efficiency), and if the PSU smokes out it takes ten seconds to pop in a replacement since you don't have to touch the adapter and cabling.

Jeeminy friggin' Christmas! What did you use for pass transistors?

Whatcha reckon, bridge rectifier with no PFC into a big fat linear regulator at 10% efficient?

Or I have 750W server PSU kits with 16AWG cabling for $50 plus shipping.

It's rare especially in the bitcoin economy, but not everyone's business ventures are based purely on greed and maximizing short-term profits.

You know, I happen to know a guy whose rates are better than theirs, and has hosted hardware for QG before.

Wait, what? He's building a gaming system, not a GPU mining rig, and wants an open-air case like people have used in the past for GPU mining rigs. Nothing you just said makes sense.

Is Spotswood still building stuff like that? I remember seeing something in the Marketplace (https://bitcointalk.org/index.php?board=75.0) a month or two ago.

If it's the Dell Z750P/N750P, that's my department. Pmorici has adapters for the DPS-800 and DPS-1200 from HP servers.

Whatever happened to these? Did they all sell?

Regulators typically aren't designed to sink current, but to source it. The 5V buck regulators on our PSU boards won't work as sinks so getting 7V across the 12-5 on them doesn't work. An actual high-current rail on a PSU is probably more readily able to work with sinking currents, especially if the current is quite a bit lower than what it's capable of handling in output. It kinda depends on the topology of the regulator. I wouldn't trust most things to handle reverse currents near high enough to power an S5, even at 9V loads.

I've thought about doing the 36V chain also, but I don't have any string miners to test with. Four boards on a Prisma would do it, except you'd need level shifters for the serial lines, which could be problematic. S5 there's no trouble stacking, since the only IO is ethernet, which is an isolated line independent of local ground references. You couldn't put two boards of an S5 in series on the same controller without smoking the controller, but four whole machines should work fine.

We're working on a prototype regulator for adjusting voltages for string miners; hopefully we have some good numbers in the next week or two.

Is this still a thing? I have buckets of BE100 chips but it looks like that's taken care of already. I've also got some Sierra and Habanero which, if I can't get 'em working, could supply some Golden Nonces. The only Avalon 1st-gen chips I have unattached are also exploded from a hot-shorted VRM.

What news of this project?

As long as you don't exceed the current ratings on the cable's pin sockets, which will probably fail long before 16AWG wire would. Depending on if they're standard or high-spec pins, probably good for around 9 or 12 amps.

Still looking to buy miscellaneous stuff. I did a bit of talking to some guys about BlackArrow X-3 but they kinda stopped responding. We're also looking for Avalon Gen3 stuff, most anything BFL, any of the hundred different USB miners, older KnC hardware... basically, anything in good shape that we don't already have two of.

The regulator he's linked is a switching regulator that takes in 12VDC and only 12VDC, then uses a high-current PWM pulse and lowpass LC filter to get an adjustable DC voltage lower than 12V out of it at relatively high efficiency. It does not put any load on 5V, 3.3V or anything else.

Additionally, if you connect a load between 12V and 3V then draw 20A, the 3V will see a -20A not -80A.

With a 4-wire fan, you can also get speed control by pulsing the PWM line (usually the blue wire). It takes an open-collector (or open-drain if using FETs) pulse driver, nominally around 24KHz, and the duty cycle determines the speed using the fan's internal circuitry. Something like that can be wired up with a 555 timer or some comparators in not very many minutes. There's no real load on the PWM line (milliamps), so you can control basically as big a fans as you want.

Dig around in CrazyGuy's Prisma sales threads. He's got a Minera image for the RPi that isn't terrible; I've had Prismas running with it in hosting for a while.

Also, Icebreaker, I have no problem agreeing with you that most people are stupid, and a lot of people make bad decisions, and most of them would rather spend all day ascribing blame than work to fix it and move forward. In America at least, profiting maximally from minimal effort and taking to the woodshed any available scapegoat when things don't work perfectly for you is almost mandatory, and I hate that about our culture. I just wish people in the bitcoin industry would stop making it so easy to do.