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Post by mchoi32 on Jan 21, 2009 14:30:30 GMT -7
About to buy new tubes and I want to learn how to bias my own amp which is the EZG-50. Are there tips/notes for the EZG-50? I took out the chassis and it seems pretty straight forward, the bias trimpot is right there... But I am trying to figure out what are optimal settings for this amp and can't find it on the Z website or in the forums.
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Post by djc (Dave) on Jan 21, 2009 19:05:07 GMT -7
I emailed the Doc December 1st with that same question. He emailed me back with this answer:
Let me see what I can do.
Two things though:
1) I’m in the process of a complete overhaul of my website.
2) I’m not real happy over the original bias notes, the wall volt is VERY important for that simple adjustment to work correctly. So I will need to overhaul all the notes with fixed wall voltages stated.
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Post by Curt on Jan 22, 2009 14:03:01 GMT -7
Correct, Wall voltage changes move every thing around.
You'll need to know the plate voltage your amp is running to be dead on.
And I do not know that number on your amp on your house circuit, but if want a safe target to start with, 6L6's tend to be happy around 32mA.
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Post by hdahs143 on Jan 24, 2009 11:07:16 GMT -7
This is a good source I use at work all the time. As cool as you can run them and still sound good is what to shoot for. The amp runs cooler, and the tubes will last longer. Anywhere from 60-70% of max safe plate dissipation is usually a good neighborhood. www.webervst.com/tubes1/calcbias.htmHarold
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Post by Phil (aka Phil) on Jan 24, 2009 16:28:39 GMT -7
Actually I use Myles' spreadsheet here: www.guitaramplifierblueprinting.com/load-nov01.xlsYou just put in your plate voltage where it says "anode voltage" and fill in the "maximum design anode rating" i.e., the tube's rating, hit "enter" and there you go.
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Post by mazmaster on Jun 20, 2009 22:04:59 GMT -7
Actually I use Myles' spreadsheet here: www.guitaramplifierblueprinting.com/load-nov01.xlsYou just put in your plate voltage where it says "anode voltage" and fill in the "maximum design anode rating" i.e., the tube's rating, hit "enter" and there you go. But, make sure you use a variac or, better yet, a high quality regulator to set the input voltage to 120 VAC and keep it there during biasing and when performing. For every 1 VAC deviation in wall voltage, you get about 4 VDC variation in plate voltage, which can drastically throw off your adjustment.
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