Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by tribi9 » Tue Nov 11, 2008 3:35 pm

And one more with a labeled PT for us rookies, but of a Blackface champ...   :P




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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by atomicmassunit » Mon Mar 16, 2009 4:53 pm

Hey guys, new to the board.  I work as an amp tech, so if you need any help with any of this stuff, let me know.

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rugby style
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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by rugby style » Tue Mar 31, 2009 12:12 pm

Another question for the veterans - The schematic for the amp I'm working on specifically lists 1W and 2W resistors near the filter caps, but no wattage is specified in other areas.  Can I assume 1/2 watt where not specified?

On an electronics component site I found the following, relating to replacing older carbon resistors with newer metal oxide versions:
Wattage: Available at 1 Watt and 2 Watt. Replace your 1/2W carbon comp with 1W metal oxide..
So I guess it's not really an exact science, and going larger when in doubt is safe?
Last edited by rugby style on Tue Mar 31, 2009 12:26 pm, edited 1 time in total.

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rugby style
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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by rugby style » Tue Mar 31, 2009 4:25 pm

My schematic doesn't, but I found another revision online, which does indeed spec 1/2w unless otherwise noted.  Thanks for your help!

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by knathan » Wed Apr 01, 2009 1:26 pm

Brad- this is an awesome thread/ tutorial...will come in quite handy when I begin my first attempt :ph34r:
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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tutorial!

Post by billaftermath » Wed May 06, 2009 12:32 pm

I have been trying to figure all of this kind of stuff out. Just finished school for the year, so I am gonna focus on doing this for a bit.

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tuto

Post by Keegan » Mon Aug 02, 2010 6:03 pm

Is a standby switch just a kill switch for the high voltage from the transformer so that the tubes have time to heat up before any high voltage is applied? I wanted to add one to my Blackheart since I never use the 3w/5w switch.
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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tuto

Post by misterMagoo » Thu Oct 28, 2010 1:30 pm

This thread is awesome!!! It's really helping me with the mods I'm doing to my AC30!

Here is another link that may be very useful:
http://www.freewebs.com/valvewizard/" onclick="window.open(this.href);return false;
lifereformatted.wordpress.com

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing tuto

Post by Sanibel » Mon Apr 25, 2011 8:40 am

Thanks for all of this information - it's fantastic!

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing

Post by RaDana » Thu Jan 12, 2012 11:03 pm

I was just curious, if you wanted to lower the wattage of your amp, you would apply Kirchoff's Law (V=I/R), no? Lets say you had a large transformer and wanted to step down--a 50w amp to run at 30w or a 100w to run at 50w--all you would need is a large resistance such as a large (series) of resister(s) following the transformer, yes? I understand voltage as what pushes the current through the circuit, so would this then in effect act as a yoke to prevent the amp from running untethered and destroying itself?

Hope I made my thought-process clear :jacked: ....

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Re: Tube amp schematics 101, etc: NEW NEWER UPDATE: Biasing

Post by RaDana » Fri Jun 08, 2012 9:34 pm

If it helps anyone else whose a visual learner, I found some videos that look pretty helpful.

http://www.youtube.com/user/glprecycledsound/videos" onclick="window.open(this.href);return false;

Plus when you look at the videos you can find similar videos on the right side bar.

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