Well, the Sigma-11 power supply came today from Rockhopper Audio, for the low, low price of $200 shipped. Came out of the box looking sexy.

UPDATED with more info...

The unit: Pretty simple - it has the same aluminum case as the M3. Its front panel has a single tiny centered orange LED to let you know it's alive. In the back, there's an umbilical to connect it to the M3. A standard IEC inlet with an on/off switch connects a power cable of your choosing. You can put the M3 on top of it, so that they can be friends. Together, they will work to make your music sound good.

Parts:
This is a well made power supply packed with expensive parts. The 1500uf 63v nichicon caps in the power supply are nice. The Avel Lindberg 30va torroidal transformer inside is worth $37. The IEC inlet is a Schurter DC11, which is worth $9. The resistors are entirely Dale Vishay. There are four Schottky rectifier chips, and the power is transistor corrected with 17A MOSFETs connected to large Aavid black aluminum heatsinks and is also handled by six bipolar transistors. Lots of boutique parts in here make it well worth the $200 as it is built to last. The thick black aluminum enclosure keeps everything cool and it's nice that it's the same one as the M3 has.

The sound: A substantial ($200 = worth it) improvement in the sound. The soundstage widened slightly, sounds were more transparent and detailed. There was a sense of blackness and a clearer space for the sound with no sense of strain. Bass was deeper and more controlled. Midrange harshness was limited to nonexistent. Highs were as crisp as before but unfatiguing. The amp went up a notch in refinedment. This is a must have, and if you own an M3 without one, you should pray that you get the next available one from Stephen. I have both power supplies plugged in so that I can A/B, and it's a night and day difference - the amp just has a more effortless sound that has just tightened up significantly, like you are at the eye doctor and they show you lense 1 and lense 2 and you are picking the sharp lens. Still, the power supply keeps the sound moderately warm and not analytical enough to ruin the music...still, every detail comes through and bad recordings will stay bad.

I will reiterate one thing...while my 336SE is fixed (Bendix Crosley very old 6SN7 for $15 on ebay, eat that + 6N8P cleartop RCA) and does not hum and has sexy tubes in it (have not fitz modded yet and won't for now) and has very competent and appealing sound that threatens the M3 greatly, I think the M3 will work with a wide array of headphones (my super low impedance Sonys are doable with it) and it is unparalleled in listening pleasure for rock, electronic, rap, anything that demands detail and precision over a thick, sultry sound. The areas that the 336 surpasses the M3 are subtle, but it is not subtle the ways the M3 beats the 336, if that makes any sense. The M3 in other words is nearly as good at certain genres (jazz, light vocal stuff) while greatly surpassing the 336 in other areas with this power supply added to the mix.

Updates will occur when the 627/637 op amps come, and I have taken under advisement the different AD op amps i was recommended, but I am sticking with burr brown for now.

Some pictures:

The stack:



Yes, my 336 is looking sexy, you don't need to tell me...

Inside the little beast:



Come on, do you really want this powering your M3? I cracked open a comparable wall wart from a defunct possession of mine - enjoy!

Very nice! Been thinking about going this route for an amp.

Come over to the solid state side, we have cookies.
Augh, wait, so does my 336.

thanks for the review. the stack looks great. now if only Stephen/Thrice would get back to my email, i'd get one off him

Yeah, if only he were a factory and not one man, he did such a nice job.

I wonder if there is any difference between the Sigma-11 PSU and STEPS PSU. They are both of good quality, so I can't imagine it being a noticeable difference.
Any thoughts?

Quote:



i think the STEPS/YJPS/Elpac all have a max current output of 300mA while the Sigma-11 is usually around 1A. the YJPS and Sigma are both close in performance otherwise. the STEPS is an older model and not quite as good as the YJPS and Sigma, but better than the Elpac.

Nice review, I've been considering getting one for my DAC for a while... Hrm.... Must resist!

The Sigma11 is a very nice PSU, congrats.

Shahrose: STEPS, YJPS and Sigma can output huge amounts of current, easily upwards of 1A, no real problem there.

The Sigma is just a very nice tracking PSU while the YJPS is opamp-corrected and the STEPS is just a nicely implemented LM317 PSU.

At $200, that's quite expensive, but you're paying for quality build with warranty and matching case.

STEPS is a totally different design, it's not as overbuilt and as FallenAngel said it's not transistor corrected. As the pictures show, the Sigma is jammed with goodies and has a very nice full-size torroidal transformer...I know a lot of smaller designs using those blue, flat, PCB mounted ones which I have my doubts about. The case and finish are also very good - if you want a PS that matches your M3, this is the way to go. I like the performance that comes along with the separation of parts, the sound has a perfectly black, noiseless background.

No real triggers to be pulled unless Stephen can churn out a few more.

Now, what'd really be nice would be some sort of special circuitry to where it could output both 24V and (I think) the 5V that my DAC requires. Pretty sure I'd need a second sigma which would be beyond overkill for my puny Moodlab.

You can think of the σ11/σ22 as "opamp corrected" as well. In this case the "opamp" is implemented with discrete transistors.

LM317 is rated at max of 1.5A (and will current limit if you ask for more). I recall tangent saying that YJPS is good for ~330mA. The σ PSUs have two 17A MOSFETs in parallel per rail, and it has no current limiting, so it's capable of truly huge current peaks (tens of amperes, limited only by the rectifier diodes and transformer). For continuous current draw, all three are limited by the amount of heat that could be dissipated, but the σ is definitely capable of a lot more current than the other two.

Can these be adapted for, say, HeadRoom designs?

best,

o

Quote:



Yes, but you'll need the σ22, not the σ11. As far as I know almost all HeadRoom amps and DACs use +/-15V dual rail supplies, with a 5-pin DIN connector.

Of course, the obligatory disclaimers -- proceed at your own risk, etc.

Quote:



Thanks for the reply -- I think I may give it a go.

best,

o

well i just received my sigma 11. tbh, i was expecting a pretty subtle improvement, but i got changes that were immediately noticeable. 2 areas i feel have improved enough for me to hear the changes readily: soundstage depth/air and the decay. i noticed the attack was already very fast but the slightly sluggish decay made my DT990's sound boomy (this is all relative, since they didn't sound boomy, but compared to how they sound now, they did). now you get quick thwacks with bass beats. electric guitar and bass lines are very detailed.

i didn't notice any other changes, the background is still absolutely black, like it was before. i'll have to spend more time to check if there are any other changes. i think with this latest addition, i've reached end-game wrt to amps. it's hard to imagine how something will improve significantly over this amp+psu for any reasonable price.

Edit: i also forgot to mention that these changes are more noticeable with the DT990s than they are with the HD650s....and a question: should i leave the PSU on all the time and use the on/off switch of the M^3? or the other way around? or turn them both off after use?