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Post subject: Bassman Amp Bias Pot, Where Is it?
Posted: Wed Dec 22, 2010 3:54 pm
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Hi all,
According to my date code, My '59 Reissue Bassman was made in February of 1994. It needs some tubes and I would like to re-bias it. Could someone tell me where I can find the Bias control? I was told my amp should have one, but I can't seem to find that sucker.

Thanks a bunch!
-Chris


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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Wed Dec 22, 2010 8:54 pm
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Only the Bassman LTD versions have the adjustable bias pot.

HTH

Arjay

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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Wed Dec 22, 2010 11:29 pm
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Thanks Arjay.

Do you know of any reference materials on the web that could help me install a bias pot in my amp?

Thanks!
-Chris


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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Thu Dec 23, 2010 1:42 am
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Off the top of my head, no.

But it you re-post this in the 'modern amp' section, "shimmilou" or "bluesky636" will prolly be able to help you as they've done bias-pot installs in other Fender amps that didn't have one from the factory.

HTH

Arjay

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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Thu Dec 23, 2010 6:00 am
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Arjay,

Is that because they use a different form of biasing vs. the BF models?
"fixed bias" ??
Been reading what you and others have been saying about bias in recent posts and trying to see if I'm picking things up correctly.... You know what they say? "A little knowledge..."
:?:

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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Thu Dec 23, 2010 2:52 pm
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tyronne wrote:
Arjay,

Is that because they use a different form of biasing vs. the BF models?
"fixed bias" ??
Been reading what you and others have been saying about bias in recent posts and trying to see if I'm picking things up correctly.... You know what they say? "A little knowledge..."
:?:


Well the original 5F6-A was fixed (cathode) biased and so were the first of the re-issues. But Fender (wisely, to its credit) decided to up the ante by developing an ever better tweed Bassman. Thus the "LTD" variant was born. In addition to the solid pine furniture and the lacquered finish on the tweed, an adjustable bias pot became a fixture since many owners added one to the original re-issue to explore various output tube options. This feature permits optimizing the output stage for 6L6, 5881, or even (some say) 6CA7/EL34 bottles. The cost for an after-the-fact bias pot installation varies but I'd say $200 is not beyond the realm of reality, depending upon where one lives.

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Thu Dec 23, 2010 4:32 pm
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Retroverbial wrote:
tyronne wrote:
Arjay,

Is that because they use a different form of biasing vs. the BF models?
"fixed bias" ??
Been reading what you and others have been saying about bias in recent posts and trying to see if I'm picking things up correctly.... You know what they say? "A little knowledge..."
:?:


Well the original 5F6-A was fixed (cathode) biased and so were the first of the re-issues. But Fender (wisely, to its credit) decided to up the ante by developing an ever better tweed Bassman. Thus the "LTD" variant was born. In addition to the solid pine furniture and the lacquered finish on the tweed, an adjustable bias pot became a fixture since many owners added one to the original re-issue to explore various output tube options. This feature permits optimizing the output stage for 6L6, 5881, or even (some say) 6CA7/EL34 bottles. The cost for an after-the-fact bias pot installation varies but I'd say $200 is not beyond the realm of reality, depending upon where one lives.

Arjay


Thank you Arjay.
:?: So the OP has a 59" Bassman but only the recent "Vintage Reissue '59 Bassman LTD" , have the bias pot?

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"You can't spend what you ain't got, you can't lose what you ain't never had" ~ McKinley Morganfield


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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Thu Dec 23, 2010 7:10 pm
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tyronne wrote:
So the OP has a 59" Bassman but only the recent "Vintage Reissue '59 Bassman LTD" , have the bias pot?


Correct.

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


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Post subject: Re: Bassman Amp Bias Pot, Where Is it?
Posted: Fri Dec 24, 2010 5:06 pm
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Thanks for clarifying that for me. I had a feeling I was going to have to install a bias pot myself.
:(


Happy Holidays!
-Chris


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