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Old 29th December 2011, 07:04 PM   #1461
massimo is offline massimo  Italy
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Very nice George, congrats
Just a question: where did you connect SSHV2 sense + and -?
Sense + to the #26 anode and sense - to the star gnd?
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Old 29th December 2011, 07:08 PM   #1462
vgeorge is offline vgeorge  Greece
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Maybe 170Vdc. Pls, either simulate or make a test. There is going to be some voltage sag.
I like to have higher voltage transformer and adjust B+ with a small capacitor in front of the choke.
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Old 29th December 2011, 07:13 PM   #1463
vgeorge is offline vgeorge  Greece
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Quote:
Originally Posted by massimo View Post
Very nice George, congrats
Just a question: where did you connect SSHV2 sense + and -?
Sense + to the #26 anode and sense - to the star gnd?
Correct, but as I use a transformer, sense and force + to it' s input, not to anode.
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Old 29th December 2011, 07:20 PM   #1464
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Wich dimensions have your chassis?
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Old 29th December 2011, 07:33 PM   #1465
massimo is offline massimo  Italy
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Quote:
Originally Posted by vgeorge View Post
Correct, but as I use a transformer, sense and force + to it' s input, not to anode.
Thank you. I asked this question because I saw a red wire coming out from the SSHV2 going apparently to the tube anode. I was wrong then.
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Old 29th December 2011, 07:52 PM   #1466
vgeorge is offline vgeorge  Greece
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It's one red wire coming from the transformer. Two red wires leaving SSHV2 going to transformer.
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Old 29th December 2011, 10:03 PM   #1467
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I think there's a growing bunch of people who see filament bias as the best sound you can get out of the 26. I know most of you don't start with a small cap (220uF) and choke input before the filament reg, but I found this gave a nice increase in sound quality. I use 280mH chokes rated at 2.7A - simply because I bought a few off a dealer. But Hammond chokes are another option.

We seem to be moving towards a "standard" design with filament bias and a Salas reg. LL1660 seems to be the default transformer option, but I'm sure there are some tasty hand made options out there as well, and there are some very skilled winders on this forum.

andy
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Old 30th December 2011, 03:26 PM   #1468
vgeorge is offline vgeorge  Greece
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Quote:
Originally Posted by merlin el mago View Post
Wich dimensions have your chassis?
43X33cm PS unit 43X26
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Old 30th December 2011, 03:37 PM   #1469
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Thanks George have a Happy New Year.

Cheers,
Felipe
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Old 31st December 2011, 06:55 AM   #1470
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Default filament board brought almost 6 months ago

Quote:
Originally Posted by Rod Coleman View Post
Hi George, Looks like good layout and build!

Voltage Rating for Filament Bias:
With correctly specified C1 and R8, any new kit can be configured to run Filament bias up to 45V or so at the input.

With changes of transistor 200V is possible - though I can't imagine it is needed.
Flexible operating voltage - the beauty of discrete-transistor design! New V4 kits are available for Filament bias.
Hi Rod,

I still have a pair of your boards sitting on the bench of which brought out from you almost 6 months ago. I'm going to cut my chassis and lately found that people have good result on filament bias. Are my boards suitable for the purpose by changing some value of parts ?? Please kindly advise.
Regards

Albert
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