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Old 1st January 2012, 08:49 AM   #701
M Gregg is offline M Gregg  United Kingdom
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I have an idea,

I intend to leave the top plate alone,
I have a dividing plate that the tube bases are mounted on, (I'm going to leave this alone as well) and mount another false plate under the dividing plate. This I intend to use as the heat sink for the Mozener. The dividing plate has large holes for air flow so the hope is the air will travel across the new plate and through the holes...

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M. Gregg
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Old 1st January 2012, 09:11 AM   #702
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Your layout is probably better than mine with several heat barriers.

I thought of putting the Moz on the side of the case.
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Old 1st January 2012, 09:24 AM   #703
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
Your layout is probably better than mine with several heat barriers.

I thought of putting the Moz on the side of the case.
I find that a double skin works well even with just a 3-5mm between as long as there is air flow across / between the surfaces.

I also found that there is little point in trying to cool an area of metal sometimes its better to isolate it from the chassis and let it do its thing..The reason is anything attached to it to try to cool it will just come up to the same temp...and cause even more problems.. The wooden sides prevent heat transfer between levels..also stops ringing..as long as the heat is managable on each plate..
another thing that works ok is to put a row of holes between two areas of the metal the heat transfer is slower and a heat reduction can be had across each side of the holes...down side is loss of strength caused by the holes..

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M. Gregg
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Old 2nd January 2012, 01:40 PM   #704
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Hi Gregg ,very nice amp build , congratulations !! .
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Old 5th January 2012, 06:16 PM   #705
M Gregg is offline M Gregg  United Kingdom
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Just for interest,

Mozeners fitted started burn in.... A couple of orange drop 716 in the 1st to second stage coupling just for a test..


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M. Gregg
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Old 5th January 2012, 06:21 PM   #706
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What voltage and current did you get ?

How even is it wthout the trimmers ?
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Old 5th January 2012, 06:30 PM   #707
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
What voltage and current did you get ?

How even is it wthout the trimmers ?
I haven't measured it yet just listening...I have only just completed the mod

So I will measure it as soon as I get a chance (work getting in the way)..

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M. Gregg
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Old 5th January 2012, 06:46 PM   #708
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How´s first impression ?
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Old 5th January 2012, 07:27 PM   #709
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
How´s first impression ?
It's very loud..

With two heaters on it's a bit much to stand in front of the speakers...I am also concerned about damage to the speakers the cones are being driven quite hard... at these volumes...YMMV

sound is clear and powerfull...its a bit early to tell yet it needs to burn in..

I'm only using the mozener as a clamp....so the heat will be less spread across the resistor and FET.. cap still in place at the moment...

I don't want to use the trim pot its another pain in the ....like fixed bias..
...it's almost cheating....so I might change a few resistors to get it close..LOL


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M. Gregg
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Old 5th January 2012, 07:34 PM   #710
M Gregg is offline M Gregg  United Kingdom
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Its interesting,

I think I prefer the sound of one heater ....wonder why ...sound is smoother and perhaps warmer..triode sound comes to mind...

Anyway I will do some tests when I get chance..

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M. Gregg
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