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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 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.

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 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.

What's missing in the schematic? I assume this is the BH you are talking about?

Seems that all of us forget from time to time that "I don't know" is a perfectly valid answer...

Yes it would! Trying to find #&!*^ 0805s or their ilk after I drop them and they go under my workbench is a massive fail exercise. Strangely, both my kids liked doing SMT better than thru hole. A good pair of tweezers is invaluable as well (think I found the ones I use at one of the bead shops my wife frequents). Now there's a hobby

There was a reason I had a beard for 20+ years. Always loved that mothers cover

I agree. I wondered what became of her and if someone had pissed her off or something. Real life? What a concept...

Yeah, I initially took it that way as well (read it as used as a headphone amplifier). I run my HP amp right off the tape outs on my pre (SE) as well, works great; even better with mine in that the pre doesn't have to be on.

You're right... my opinion doesn't mean jack, but I stated it anyway. And yes, I have read much of this forum and site.

Inane posts like this are best left back over there (HF) imo...

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.

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.

Looks nice, although I'm not familiar with (as in never heard of) Wilton. A bit bigger than mine (10" Delta); could come in useful if you decide to build yourself a turntable, etc.

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).

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

Something like this: PAiA - K114 Dual Unregulated Power Supply, Building Block Kits, K114

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.

FTFY... good idea tho, might have to do that

Damn... too bad my Mac is a G5 (well, not really as I still like it alot )

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

Oh, also, forgot to add this:

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

x34 whatever we're up to now...

Got a chance to play around with this more today. First thing I did was change out the power entry caps (470u 16V) for a pair of Pana FM 470u 25V. The 35V version of this cap won't fit BTW. The caps on the reg outputs are Nichicon Muse FX (I think) 220u 25V, so I left these alone as IIRC 3 terminal regs don't like low ESR on their outputs. I thought the input caps were worth changing on their voltage (16V, a bit low for a 14.5V + supply input) and their temp rating (85C). I have been doing listening tests using a Sony PCDP line out into the HPA and then into my AKG K601s. I tried the following: +/- 12V bench PSU +/- 15V bench PSU +/- 12V Sigma 22 +/- 15V Sigma 22 I really didn't notice much if any difference between these. The 12V levels gave working DC of ~10V at V+/V- (pins 8 and 4) of the OP275s as it is too low for the regs to regulate. The 15V levels gave ~12V at V+/V-. I was using an Enya CD as test material, and did notice a bit of upper midrange "steeliness", but this could very well be the source. Power draw was backwards from what I previously had posted: + rail ~350mA; - rail ~260mA. At this point, I would think a pair of Treads might be the best and most cost effective PSU to go with. The Sigma22, while nice (really nice), doesn't seem to buy you enough to warrant the cost. Which of course wouldn't keep me from using it 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).

You'll get over it...