A warm system is a sweet system....

jstang

Honey,I can't hear you...
Never fails to amaze me how sweet my main system sounds if I leave it on over night... Over last month or so, I have been shutting the whole system down to give things a kind of rest... if you will...

Ok makes sense so far.... But the detailing is really improved this morning....

I have a CD-Pro transport, a custom DAC with tube output.... 1541 DAC chips are known for needing to be warmed up.... OK so far so good.... usually shut down the tube output and leave the DAC and Transport powered up....

My 7T is generally left on for months.... it only uses 7watts...

Left my 500 on over night.... Which I usually shut it down after listening... Last night I forgot.....

So the whole shebang was powered up over night...


May be the huge main filters in the 500 needed some long term charging to form up completely.... Or the DAC or the tube output or the transport.... or all of it....

Not the first time I have noticed this.... Cap ESR does lower with a reasonable rise in temp and maybe some biasing levels shift...

"A warm system is a sweet system.... and a happy listener". Hot is no good.....

John
 
First time poster here.

Recently came into possession of a Marantz 7t and I've gotten out of the habit of turning it off. Always find after an hour or so the sound opens up. I suspect the unit is going to need some TLC at least replacing the caps tho as it all appears to be stock components despite very few signs of age.

Just drool over the thought of a modded 7t paired with a 500 or model 9's (some day)! Currently i'm just using my restored 2245 as my power amp. It's serviceable and the 7t blows the built-in phono section on the 2245 out of the water.. but definitely feeling the urge to mod that 7t and find a synergistic power amp maybe a 250, model 16, or 32
 
DADRock... Your first post :) and you're diving in with a 7t ? Good on you.... and welcome on board.


Yup the 7t is usually left on during the winter, cause that is when I do most of my listening.

But it does seem to sound sweeter after being on for some time from cold.

So here's the "Warm Up" break down in order of the signal path....

1. The transport has a low jitter master clock. Temp does affect jitter... This definitely sounds better warm, maybe +24 hours to hit its peak.... Has its own power supply and AC power cable. Feeds the DAC via an "I2S" digital interface.

2. The DAC is a combo of customized home built with four TDA1541 S1 DAC chips.... Absolutely needs to be warm.... And seems like +24 hours is where it peaks.... Has its own power supply and AC power cable. First turned when cold is ok sounding, but on for 24 hours and wow.... It feeds the tube output via a "low level current source signal".

3. DAC tube output is again a customized kit. Using 6DJ8 tubes. From there to the 7t via some MIT interconnect cables. Has its own power supply and AC power cable. Does not seem to care much about warm up, 10/15 sec after power and it sounds great.

4. Modified Model 7T..... what else needs to be said..... Seems to like at least an hour to hit its peak.... Feeds the 500 via MIT interconnects.

5. Modified Model 500.... what else needs to be said.... Seems to like at least an hour to hit its peak if its been used recently.... I think the 500 wants 24 hours of powered up time if you have not used it for some time. Feeds the OHM Fs via MIT speaker cables...

Lots of separate power supplies, power switches and power cords in this system to play this game. Which you have be careful with.... POWERING UP AND DOWN IS AN EXERCISE knowing which goes first.... which is another reason most of it is left on during the winter.

During the winter, I usually leave the DAC, Transport and 7t powered up. When ready to listen, the tube output it powered on, wait 10/15 seconds and power up the 500.

Summer, I usually shut most of it down because I am out of the house a lot and listen a lot less.... Winter I listen at least every other day.... So just the tube output and 500 are shut down.

Caps and refurb on all the units within 10 years or less.... Not yesterday, but gosh there is a lot of electronics in this system, customizing and I have done a lot of testing of different mods over the years... I have pretty much noticed for the DAC the 24 hr warm PEAK for years now and the TDA1541 is well known to sound better warmed up. But just noticed the 500 seems to like being run 24 hours if it been sitting for weeks or more....

In other words if you run the 500 every other day.... 1 hour of warm brings it to it's peak... But if it been sitting for a few weeks.... It might need to run for 24 hours to hit it peak.... 100000uFs of supply filter caps in it. Shut it off over night and turned it on earlier to let it warm up... it is sound great like yesterday after the 24hr run in....

By the way, the DAC has a huge filter cap bank too.... like 40,000uF at 15Vs.

Maybe it seems the more supply filter cap you have the more you need to let the system form, warm and stretch it legs...to hit its peak if its been powered down for more than a day or so.... Other factors too....


Johnk
 
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