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Old 20th December 2011, 07:05 PM   #621
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Resistor failure probably to low voltage rating.

Itīs starting to come alive, sounds better for every minute.

Canīt turn it all the way up starts distorting badly at 75%.

Iīll let run at 50% for a burnin period before starting to measure which stage is doing what.

Have start figuring out a way to trick it into playing a little louder .
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Old 20th December 2011, 07:28 PM   #622
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
Resistor failure probably to low voltage rating.

Itīs starting to come alive, sounds better for every minute.

Canīt turn it all the way up starts distorting badly at 75%.

Iīll let run at 50% for a burnin period before starting to measure which stage is doing what.

Have start figuring out a way to trick it into playing a little louder .
Great!
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Old 20th December 2011, 08:01 PM   #623
M Gregg is offline M Gregg  United Kingdom
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Is it sill running??




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Old 20th December 2011, 08:06 PM   #624
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Loud and its way past bed time

Details are coming out think the russians need some time.
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Old 20th December 2011, 08:07 PM   #625
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
Loud and its way past bed time

Details are coming out think the russians need some time.
But it's only 1.5W...LOL



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Old 20th December 2011, 08:17 PM   #626
M Gregg is offline M Gregg  United Kingdom
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The 6C33C's need about a month to burn in..

They start to sing after about 30 mins..

Do you have the option to run on one heater?
(I would give it a while before you switch to one)

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Old 20th December 2011, 08:32 PM   #627
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I have a switch installed.

Will run it for some time before messing with it.

First time since start that i feel like iīm ahead of it.
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Old 20th December 2011, 08:34 PM   #628
M Gregg is offline M Gregg  United Kingdom
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Quote:
Originally Posted by flatheadmurre View Post
I have a switch installed.

Will run it for some time before messing with it.

First time since start that i feel like iīm ahead of it.
Thats great!

I'm really looking forward to your progress..

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Old 21st December 2011, 04:08 PM   #629
M Gregg is offline M Gregg  United Kingdom
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Just a few tests,

1st stage CCS now has CC 330 Ohm + Ferrite bead.

2nd stage CCS still 270 Ohm + Ferrite bead.

The bead is insulated from the resistor leg (on the gate side) with PTFE sleeve.
No instability and highs are more open..

New 716 orange drop in the PI output to 6C33C's just for a test...burn in taking place...curiosity!

Looking at cathode CVS across existing resistors....

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Old 21st December 2011, 04:22 PM   #630
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Measurements tells that bias voltage in the output stage must be stabilized.

The amp delivers about 10watts before it drifts due to lack of stability.

It drifts of into classB land when run hard.

A zener referenced fet will do the job as constant bias voltage i hope.

Another way is to run it hotter someone experienced please shout if iīm on the wrong track.
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