Temperature test...

[Manoet]

    Here's the temps after 4 hours of non-convection, purely conductive cooling provided by the high efficiency thermal pads and whatever radiant cooling the black anodized case can contribute to the equation. I'll work on percentage differences later today.

One thing I want to bring up from the past; Several months ago Rufus (I believe) was mentioning how he thought hotter temperatures were affecting his SQ negatively. I didn't think much of it initially because temps are "what they are"... nothing I could do about it. Once my temps climbed back up from near or below 30C to high 30's there was a distinct SQ degradation that I presume would've continue to degrade if they continued to climb! I've no idea at what point it occurred as I wasn't listening during the 4 hour temp climb. SQ is still better than pre-mods but significant enough to be high-profile obvious. It found me rather than the other way around and made me think of Rufus' post. So for those wondering, I have to think temps play a significant, if not dramatic role in SQ. Its far too high-profile obvious to be placebo and like I said, I didn't even think about it... it found me!

[Manoet]

    Here's the temp-mapping of the D200 top surface taken at same time as above 'without-convection' temps in red ( vs yesterdays 'w/convection' temps in black). Additionally I've labelled the surface quadrants from Q1, clock-wise to Q4 as I suspect this won't be the last time quadrant surface temps are going to come up here going forward and it'll be helpful to know what quadrant I or others might be referring to.

BTW, Q3 is where PSU lives and Q4 is where the power/filter boards/fuses etc are. A & D amps are less attributable to specific quadrants.

[Rufus McDufus]

I long-suspected the degradation was temperature-related. I did some more thorough testing over the summer and ended up finding the temperature-SQ link a little less conclusive, but I did find there seemed to be a noticeable SQ dip as temps rose - though at a higher temper threshold than I previously suspected (in the mid-late 50s C as opposed to the mid-to-late 40s). I did also strangely find my unit seemed better close to power up - maybe ten minutes in, and seemed to deteriorate from then on albeit pretty slowly until that threshold was reach where SQ dip was noticeable, beyond which it was pretty much unlistenable.

On the other hand I've suspected I have a faulty D200 for a long time as it's quite inconsistent sound quality wise from one listening session to the next. It's currently with Devialet and I have a loaner unit which seems much more consistent (i.e it hasn't sounded bad at all, even on extended listening sesssions where the temps have got quite high). So I don't really know for sure whether there's a temperature link. It could just be a faulty unit.
Another factor is the earlier units like mine were generally subjected to higher temps due to less attention paid to temp regulation in the earlier firmwares. I wonder sometimes whether earlier units could've degraded somehow due to the higher temps, but then we're not really talking very high temperatures at all in terms of electronic components/solder joints etc. which should remain in tolerance quite a bit beyond the temps we're seeing displayed.

But I'm fairly sure lower temps/higher stability of temperature (which you seemed to achieve Manoet) can't be anything other than positive.

Now if you could fool it into thinking it's a 250...! Are there DIP switches anywhere? I'm wondering how the firmware figures what unit is running.

[Manoet]

Ya gotta know if there were dip switches mine certainly wouldn't be anywhere near the OEM settings ;-) But I too am tremendously interested in Confused's theory of identical parts shared between 200/250 and only firmware is dissimilar as I believe a bump of 50 would be child's play for my D200 at this point temps-wise. If components were identical with 200 I'd jump straight to 400 without a worry in the world of overheating. I can always make it run cooler ;-)

[Manoet]

As hoped, 2 hours after convection cooling was re-enabled and normal temps A30, D29 & S31 were restored SQ returned to the jaw-dropping quality it presented at initial power up! There's a lot more to temp drop and SQ than I thought possible. Now I'm curious at what temp does SQ stop improving? Maybe if I could just install a micro inlet valve with a multiple orifice outlet manifold to inject compressed CO2 slowly and evenly into the case across the PCB width. Heh heh, just kidding... mostly ;-)

[kenreau]

Very interesting to read of your temperature and SQ interaction. I'm going to reconsider your drilling of holes for ventilation and perhaps upgraded spec thermal pads (but not the uber performance & $$$ ones...)

Kenreau

[Matthew]

This has been an interesting discussion. I've always believed (conventional wisdom) that we wanted our components to 'warm up' and would sound better after being turned on for some period of time (keeping tubes out of the discussion). So are saying that this may not be the case?

I cannot say I've heard sound differences with temperature increase/decreases but also have not previously looked for them either. This summer with a D200 in a moderately confined component rack my temps could have fried an egg! Silly me I did not look for the readings. At one point I actually turned a fan onto it (which cooled it waaaaay down so as barely to even be warm.

Last night I checked my temps, now with a D400 and both units completely open and ambient temperature at 21°C I had these results:

Temp at start up from fully off
A - D - S
26-26-28 master
32-31-35 slave

Temp after 30 mins -20.5 dB
34-32-34 master
36-34-38 slave

After 60 mins 
38-36-38 master
38-35-40 slave

After 90 mins
39-37-39 master
38-36-40 slave


I'm going to keep an ear out for SQ changes for a while.

Manoet, you amaze with your efforts!!!!

[mauidan]

Congrats to Manoet on his successful efforts to reduce operating tempertures.

I think the big improvement in SQ came from removing the filtered PEM.

[hrky_zmaj]

While I can't guarantee what I'm about to write, my gut-level suspicions of enhanced SQ would be as follows:

1. Anodized, non-magnetic/non-conductive interior walls, ceiling & floor has to be counted as H-U-G-E in such a tightly-packed electronic component! (you don't see any "chrome" smartphones!)

2. F'tech rhodium IEC install with PEM removal & high-end/high-current highly shielded pure silver leads soldered directly to power board and grounded direct to chassis (maybe even moreso than #1, hard to know)

3. WBT speaker binding posts

4. Non-magnetic fasteners & PCB stand-offs

At this point it would be hard to summarily dismiss cooler temps as sharing some measure of responsibility for enhanced SQ. They're just too dramatic to ignore! I also believe it at least possible that there's a bit of "overall improvement is greater than the sum total of parts" used 'may' be at play here.

Its a lot for even me to absorb & process as it certainly exceeds any/all my objective & reasonable expectations.

Congrats to Manoet on his successful efforts to reduce operating tempertures.

I think the big improvement in SQ came from removing the filtered PEM.

+1. Me too! I did it before and as a single step. The best tweak. Better than speakers terminal change. Thumbs up for PEMectomy !

[Manoet]

But the topic we're specifically discussing here is SQ related to internal temps, or at least that's how the thread started since we're already amidst discussions in another thread related to "what made the biggest change?" I'm lost! So are you guys saying specifically that the PEM or lack thereof makes SQ better at lower temps and worse at high temps?

**UPDATE** Nevermind guys its me confusing threads/posts. Sorry, being pulled at from too many directions!