Pars

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...

What!!!! Get back to work!

I grew up in NE Iowa. I do remember the first or second year that my wife and I lived in Chicago of driving back to my parents house on Christmas Eve with it around -25F air temp out. Semis stalled on the interstates from the fuel gelling... was a bit scary thinking about the car quitting out there around eleven or midnight, but it was relatively new so no problems. I wouldn't have done that if we had the kids at that time.

The coldest I remember is -27F... then there was the wind (20 mph+). Made walking 1/4 mile west across campus a real treat. I guess it did get down to -34F when I was 8, but I don't remember that.

In this economy? For what has to be a tiny, niche manufacturer?

Have a nice one!

Stayed employed... some weren't so lucky.

Lowest signal level present is already line level (i.e., highest level in preamp), so maybe they thought the Faraday cage wasn't needed? Silver transformers? uhhh, yeah... I'll bet those are expensive

BNC is a far superior connector, so particularly given WBT's prices, why bother?

Yes, that's what I'm saying. And the WBT actually being 75 ohms isn't verified as far as I know. It is a physics thing... the distance between the center conductor and the shell that precludes RCAs from being 75 ohm without massive rework. Read the link or do some searches on diyhifi or diyaudio... while you are at it take a look at the SPDIF xmit/receive portions as well Oh wait, you said Cryo? That changes things

I can't think of one, but...

Marketing bullshit... IIRC they measure somewhere around 50 ohms from what I've read (somewhere???). If you have to use an RCA, those are what I would use though. DIYHiFi.org • View topic - Connecting CS841[2,4] directly to the line: why not? The jury is out on the WBT ones (haven't seen anyone measure these), but these have to be used with the matching WBT sockets.

Except that there's no such thing as a 75-ohm RCA (connector)... But yeah, much of the coax used for ICs is probably 75 ohm coax.

I would be really worried with a blind threaded bore in material this thin... it is only aluminum after all.

One other thing to keep in mind with these things is that pots don't like DC on them (particularly the conductive plastic ones such as Alps, TKD, etc.) So even if you're preamp has coupling caps in it, make sure they happen before the signal hits the pot if you are thinking about using a straight LOD and cable with an iMod. In my Counterpoint tube pre, that is not the case.