AA HPA V. 1.0 Info

[luvdunhill]

None of the Elpacs put out enough current to consider, and they have gone up considerably in price (the WM071 used for the GLite is now $43 from Newark... it is rated at 240mA per rail).

what about one of the (not yet released) Twisted Pear Placid supplies? I believe it will do up to 500mA and looks like a very nice design... and nice and compact as well.

[Pars]

what about one of the (not yet released) Twisted Pear Placid supplies? I believe it will do up to 500mA and looks like a very nice design... and nice and compact as well.

Exactly why I posted this instead of just PM'ing morphsci. Thanks!

[Pars]

Oh, also, forgot to add this:

[Beefy]

what about one of the (not yet released) Twisted Pear Placid supplies? I believe it will do up to 500mA and looks like a very nice design... and nice and compact as well.

Russ says 200mA. In reply to your question

[luvdunhill]

Russ says 200mA. In reply to your question

heh... I suppose I was too busy vented about their "release dates" in that thread to remember anything

[n_maher]

heh... I suppose I was too busy vented about their "release dates" in that thread to remember anything

The best policy is to ignore everything Brian and Russ say about release dates until it's listed as "In Stock" on their website. No expectation = no disappointment. I wish it was different, but it's not, and it's hard to get upset with them considering the ridiculous amount of work they put in for very little reward.

[Pars]

Too true! Kudos to them, particularly considering it is a side job for both of them (at least I think it still is).

[Beefy]

I wish it was different, but it's not, and it's hard to get upset with them considering the ridiculous amount of work they put in for very little reward.

Yep yep. They ran out of LCDPS when I ordered my Buffalo and as compensation I got a free LCBPS and a free Placid

Genuinely good guys trying their best to do the right thing for their customers and the community.

[Pars]

I talked to Jim (morphsci) via pm and he sez go for the sigma22. That said, the one option I hadn't priced out for him would be to build a dual unregulated PSU putting out +/- 15V (or 14.5) and let the internal regulators handle it. With the current load thru this thing, it is hard to come up with adequate heat sinking for a pair of Treads, at least from what I saw playing around with Tangent's power supply estimator. The 3.7 C/W heatsink he uses as a default won't fit on a Tread as far as I can tell... Since internally, this thing uses a pair of regs per rail, it appears it would handle it without a problem.

Any pointers to commercially available boards for a dual unregulated PSU? I took a look at Welborne Labs, but the dual PSU they have is as expensive as the sigma22 and doesn't seem to be as good (non-tracking, looks like a simple LM317/LM337 job). I suppose I could lay something out myself and home etch it... I'm a bit uncomfortable doing this for someone else though.

EDIT: took a look at Google and there appear to be quite a few similar +/- 25V capable unreg PSU boards and kits for <$20... this could be a good cheap option.

[n_maher]

I suppose you could in essence make a TREAD an unregulated supply by manipulating the resistor values so that the desired output range could never be achieved. Then you'd only be dealing with the drop over the reg in terms of heat dissipation. Not exactly elegant, but cheap and might work although I haven't plugged this scenario into Tangent's estimator to see what it looks like.

[Pars]

Something like this:

PAiA - K114 Dual Unregulated Power Supply, Building Block Kits, K114

[luvdunhill]

sounds like a good option. Maybe do a simple CRC filter as well. I just cannot see a sigma22 to be practical at all, given the cost and the fact that you're not planning on replacing the regulators. If you want to spend this kind of cash, you could replace the regulators with DEXA discrete regulators or something like that and use the unregulated supply you're proposing...

[Pars]

sounds like a good option. Maybe do a simple CRC filter as well. I just cannot see a sigma22 to be practical at all, given the cost and the fact that you're not planning on replacing the regulators. If you want to spend this kind of cash, you could replace the regulators with DEXA discrete regulators or something like that and use the unregulated supply you're proposing...

Well, I could pull the on board regulators and jumper the in/outs for use with the sigma22. DEXA would probably make the sigma22 seem cheap, and probably wouldn't outperform it.

$560 for a clock? Hehe... DIYHiFi.org • View topic - cdm9 transport mod: HELP

[luvdunhill]

Here's the website with the regulators:

NewClassD Products

They also sell them at PartsConnexion.

I think P-A offers some similar chips on his website that might be cheaper.

[Pars]

Yeah, I had found DEXAs website. The point is I doubt that they outperform the sigma, but even if they do, they wouldn't fit (too tall).

[Looser101]

Yeah, I had found DEXAs website. The point is I doubt that they outperform the sigma, but even if they do, they wouldn't fit (too tall).

You can lay them down at an angle. TentLabs also sells regs (not sure they would fit your needs). IMO I would go with an external regulated supply. The amp looks rather small, so keeping heat out of it would be a consideration. A quick and dirty CRC followed by a 78xx and 79xx should do the trick. Mount it in an aluminium Hammond and use the case as heatsink. A tracking regulator is unnecessary since its regulated again inside the amp in its present configuration.

[Pars]

You can lay them down at an angle. TentLabs also sells regs (not sure they would fit your needs). IMO I would go with an external regulated supply. The amp looks rather small, so keeping heat out of it would be a consideration. A quick and dirty CRC followed by a 78xx and 79xx should do the trick. Mount it in an aluminium Hammond and use the case as heatsink. A tracking regulator is unnecessary since its regulated again inside the amp in its present configuration.

The output FETs run hotter than hell in this amp, so any heat coming off the internal regulators is miniscule in comparison (so far I haven't relt any heat coming off these to speak of). I really don't think there is room to lay those DEXA regs down (this thing is rather small physically, and the internal height is not much more than a 7812/7912. I like Tent products, but his shuntregs don't handle enough current for this (wrong product forthe job). I really think just an unregulated supply capable of 0.5A per rail at around 14V would be perfect for this... I may just toss something together quickly and listen to it.

[luvdunhill]

high current shunt reg you say?

[Pars]

Not sure what you are showing me there Marc... those do look a bit beefier than most shunt regs I have seen. The DEXAs surprised me in claiming 650mA.

[Pars]

I sent an email to Monolithic Sound regarding a PSU they used to make, the MPS, for Audio Alchemy equipment. I was surprised to get a response from Dusty Vawter (CI Audio):

I thought it used 7808 & 7908 (I didn't design it). I do seem to remember it coming with a PS-1 which was +/-15v.

If it does use 7812/7912, then you would want a +/-15v supply. I wouldn't go much higher because HPA already runs very hot due to the class A output stage.

Sent from Dusty's iPhone

I was having a hard time trying to correlate an original +/- 12V supply with 12V regulators as this wouldn't be enough to have them regulate. Original equipment of 9V regulators makes alot more sense.

Hydrocity: Any chance you could look inside yours and see what is in there? I can give you the allen key size if you need it.

[Pars]

I sent an email to Monolithic Sound regarding a PSU they used to make, the MPS, for Audio Alchemy equipment. I was surprised to get a response from Dusty Vawter (CI Audio):

I thought it used 7808 & 7908 (I didn't design it). I do seem to remember it coming with a PS-1 which was +/-15v.

If it does use 7812/7912, then you would want a +/-15v supply. I wouldn't go much higher because HPA already runs very hot due to the class A output stage.

Sent from Dusty's iPhone

I was having a hard time trying to correlate an original +/- 12V supply with 12V regulators as this wouldn't be enough to have them regulate. Original equipment of 9V regulators makes alot more sense.

Hydrocity: Any chance you could look inside yours and see what is in there? I can give you the allen key size if you need it.

[hYdrociTy]

Sure I'll look and take photos when I get mine open. Where did you get yours in that size though? Theres a lowes about five minutes away.. not sure if they carry anything that small. but if you let me know the exact size I could drop by tomorrow morning. I tried emailing one of their former techs (the guy I got my hpa from) for schematics but apparently he's now a rockstar and doesn't answer email much.

[Pars]

Mine are just a set of the ball allen wrenches. I don't even think it is the smallest size, and I got these either at an Ace Hardware or Home Depot / Lowes. Something like this (Lowes): 13-Piece Ball Plastic Handle Hex-Torx Key

I have a couple of sets, both standard and metric. Damn handy as long as one of the kids hasn't run off with it

The size you need for these is 1/16". The sets have a smaller one as well, 0.050".

[hYdrociTy]

2x7812 and 2x7819

I have to go now but here are some pics. I'll take a look with the meter later tonight.

[Pars]

Actually 7812s and 7912s. Looks identical to morphsci's. I'm going to leave his at 12V and do a 15V PSU for it, though the PSU can be dropped to 12V by pulling one resistor (R10), which will be socketed. Won't even overheat like a typical 317/337 would if you made it pull 3 volts more across the regulators.

Thanks for looking and for taking the pics Hydro!