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5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 1:55 am
by Alain Benoit
Preparations.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 1:58 am
by Alain Benoit
Bias mod.
Increased the usable range on the bias control.
Sizable improvement, a must for these amps.
Biased to ~38mA.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 1:59 am
by Alain Benoit
Replaced electrolytic bypass caps with film ones.
No idea why they designed it like this.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:01 am
by Alain Benoit
Replaced Ra's with 1 Watt CCF60's.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:08 am
by Alain Benoit
Replaced the Illinois Co's with WIMA's.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:09 am
by Alain Benoit
Replaced the tired Ruby quad with SED's.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:12 am
by Alain Benoit
Experimented replacing the 'pseudo' *cough* choke with an MM multitap, settled on 5H.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:14 am
by Alain Benoit
Changed out stripped Phillips screws for 4-40 SS barrel head capscrews.
Silly Yanks.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:16 am
by Alain Benoit
Lowered R9.
Reduced fizz a bit, darkened tone, lowered gain.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:21 am
by Alain Benoit
Dropped C2 to 22nF.
Loosened attack a smidgen.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 2:29 am
by Alain Benoit
C17 to 470k//2n2F.
Lead channel closer to 5150.
Jury still out.

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Re: 5150II (6505+) Mods

PostPosted: Sat Sep 08, 2012 11:09 pm
by Scott DeVarenne
Thanks for the photo expose. Nice pics, BTW. I understand nothing, but it all looks nice. Bottles of pills in first photo? What? With booze? Careful. You might make sick, you night owl, you.