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Old 5th March 2013, 05:45 PM   #1561
Zen Mod is offline Zen Mod  Serbia
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give us picture from bird perspective

if you're just blowing in da case , effect is minimal

you must have proper intake opening at case , same as as proper outtake opening at case

use cunning cut Roentgen foil for tunnel sides forming , if needed ( it's wise to have some friend in local Hospital )

moi could cool 158MW with that htsink and lazy Noctua

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Last edited by Zen Mod; 5th March 2013 at 05:50 PM.
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Old 5th March 2013, 06:07 PM   #1562
6L6 is offline 6L6  United States
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Quote:
Originally Posted by ZenMod
give us picture from bird perspective
If you are taking requests, I would like to see a photo from a Gazelle perspective...

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Old 5th March 2013, 08:42 PM   #1563
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Quote:
Originally Posted by Zen Mod View Post
give us picture from bird perspective
Intake openings are ~5X the area of the outlet, which was shown - the two opposed heatsinks with fins touching.

The intakes are:
a) rows of vent holes along sides of case - larger holes along the bottom and smaller holes along the top.
b) a row of ventilation slots in the top - located on the other side of the A-J boards from the fan (so resistor heat will be exhausted).
c) rows of vent holes in the case bottom immediately under the A-J boards.

Air speed through the heat sink 'tunnel' is fairly lazy to cool this...

Frank
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Old 5th March 2013, 10:03 PM   #1564
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yes , but you must have defined tunnel from one side of case to other side of case

if you dont have cold air intake and hot air outtake , all you are doing is just warbling hot air in case
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Old 5th March 2013, 11:30 PM   #1565
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Originally Posted by Zen Mod View Post
yes , but you must have defined tunnel from one side of case to other side of case
Sorry! Here the top of the tunnel is opened up, so you can see the heat sink fins and the position of the thermocouple (yellow heat shrink) for temperature readout. The case layout with closed front was intended to minimize fan noise in the room. Again, air inlets to the interior of the case are via rows of holes in the sides, bottom, and slots in the rear top. The fan draws that cool air past all of the interior components and then blows it out the back over the heatsink fins. The full back plates are not yet made, but will be split so the rear of the heatsinks are open.

Again, with the 12V 1200 rpm fan at full speed, the heatsinks rise about 24 degrees C above ambient. That fan speed is audible outside, though not annoying. With the fan slowed down just beyond the threshold of being heard outside the case, the heat sink temperature rise is ~30 degrees C. So I think I don't want more bias because in summer the ambient air temperature can easily be 10C higher. That means about 60C for silent operation, 55C when I'm rocking-out and don't care about a little fan noise. What do you think about those operating parameters?

Cheers!

Frank
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Old 11th March 2013, 02:46 PM   #1566
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Bottom line thus far - disappointed with the sound when driven by the Legato I/V stage on the DAC. It's not just the lack of volume but the lack of 'guts'. My Legato puts out about 1.7 Vrms @ 0 db (balanced). The amp sounds significantly better driven single ended by a preamp giving ~2V. I don't want a 'preamp' and I don't want to run single-ended...
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Old 11th March 2013, 02:56 PM   #1567
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some more info wouldn't make any harm ....

what's between Legato and J ?

link to Legato sch will help , too - there are to much variations for my peanut memory
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Old 11th March 2013, 03:36 PM   #1568
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Balanced circuits have double the circuit noise of a single ended circuit. A balanced circuit is only a benefit if you have significant external noise getting into your interconnects. A balanced circuit will not sound better simply because it is balanced. See Doug Self's book on Small Signals for a pretty in depth description of this.
Small Signal Audio Design - Douglas Self - Google Books
Around and after page 344.
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Old 11th March 2013, 03:43 PM   #1569
Zen Mod is offline Zen Mod  Serbia
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don't be so sure

one can claim that only for specific case , not generally

if balanced ( or any iteration of it ) is inherent to circuit construction , in most cases it will sound better than same circuit is used as any sort of SE/Bal converter

regarding Aleph J , some say that best sound is when inputing it balanced ; but I also know one serious audio designer who claims that ( for his ears ) Aleph J is sounding better when inputing it SE , but with positive leg grounded and minus leg used as active;

didn't asked him for variation with spk wires phase swapped

go figure
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Old 11th March 2013, 03:53 PM   #1570
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Never thought of that.
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